JP2003008054A - Silicon-based light emitting and receiving element, method of manufacturing the same, silicon-based opto-electric integrated circuit, and silicon-based opto-electric integrated circuit system - Google Patents

Abstract

(57) [Problem] To provide a semiconductor light emitting / receiving element and an optical waveguide for realizing optical wiring in a silicon-based integrated circuit. The silicon-based light-emitting and light-receiving element has fine particles made of germanium in a second silicon crystal layer formed by an SOI layer on an oxide film layer and an intrinsic silicon epitaxial layer. An efficient light emitting and receiving device utilizing the quantum size effect,
The light emitted by the fine particles 15 is confined between the interface between the second silicon crystal layer and the oxide film layer 11 and the interface between the second silicon crystal layer and the second silicon crystal layer on the side opposite to the oxide film layer 11. Thereby, light can be efficiently propagated into the second silicon crystal layer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a silicon-based light emitting / receiving element, a method for manufacturing the same, a silicon-based optoelectronic integrated circuit, and a silicon-based optoelectronic integrated circuit system for transmitting information using light.

[0002]

2. Description of the Related Art The operation speed of a semiconductor device is MOSFET
(Metal oxide semiconductor / field effect transistor) is inversely proportional to the channel length, and bipolar transistor is inversely proportional to the base length. Therefore, as the fine processing technology advances, the operating speed of semiconductor devices will increase.

The speed of the entire integrated circuit is determined by the operating speed of the elements that form the integrated circuit and the transmission speed of signals between the elements. Therefore, even if the speed of the element alone is increased, the advantage of speeding up the element due to miniaturization cannot be enjoyed unless the signal transmission speed follows it.

Although metal wiring is generally used for interconnection between elements, a delay time determined by resistance and capacitance of the metal wiring has become a problem as the speed of the element increases. In order to overcome such a problem, multi-layer metal wiring has been carried out, and metal wiring made of a low resistance material such as copper has also been studied.

However, in the future, as finer semiconductor structures can be processed and the speed of the device further increases, it is necessary to further increase the multilayer metal wiring structure and further reduce the resistance of the metal material. , Approaching the limit.

Therefore, an optical wiring for transmitting light is considered as an alternative to such a metal wiring. Since signals propagate at the speed of light in this optical wiring, the problem of delay in metal wiring is solved.

Direct bandgap materials based on III-V semiconductor technology, especially gallium arsenide-based technology, can form efficient light emitting elements and light receiving elements. Applying this gallium arsenide-based technology, an optoelectronic integrated circuit (OEIC) has been proposed which combines signal processing by an electronic element and signal transmission by a light emitting and receiving element.

However, in contrast to a direct bandgap semiconductor such as a III-V group compound semiconductor, a group IV semiconductor such as silicon has an indirect transition type energy band structure, and therefore the probability of interband transition is small. It has been difficult to form an efficient light emitting device and an optical wiring using the same.

However, in Japanese Unexamined Patent Publication No. 6-326359, a chemical vapor deposition (CVD) method or a molecular beam epitaxy (MBE) method is used in a silicon pin structure as shown in FIG. A silicon-based light emitting and receiving device has been proposed in which fine particles 113 are formed in a genuine silicon layer 114 by using germanium islands that utilize the lattice mismatch between germanium and silicon by epitaxial growth. By utilizing the quantum size effect in the semiconductor fine particles 113, an efficient light emitting and receiving element can be formed even with silicon.

[0010]

By the way, the above-mentioned FIG.
In the light emitting and receiving element in the conventional example, the fine particles 113 in silicon emit light with energy lower than the band gap of bulk silicon due to the transition between the formed quantum confinement levels. Since this light has energy lower than the band gap, it can propagate in silicon. In addition, when semiconductor fine particles having no carrier absorb light with energy corresponding to the band gap,
Electrons and holes are formed in the semiconductor particles. Therefore, the light from the semiconductor fine particles is emitted in all three-dimensional directions, which causes a problem that the information transmission efficiency deteriorates. Therefore, there is a problem in that it may be difficult to control between arbitrary elements as a substitute for the metal wiring.

Therefore, an object of the present invention is to provide a silicon-based light emitting / receiving element having a high information transmission efficiency, a method of manufacturing the same, a silicon-based optoelectronic integrated circuit, and a silicon-based optoelectronic integrated circuit system.

[0012]

In order to achieve the above object, a silicon-based light emitting and receiving element according to the present invention comprises a first silicon crystal layer, an oxide film layer on the first silicon crystal layer, and the oxide film. A substrate having a silicon-on-insulator structure formed by a second silicon crystal layer on the film layer is provided, and the second silicon crystal layer has fine particles made of a semiconductor.

In the silicon-based light emitting and receiving element of the present invention,
Since the second silicon crystal layer on the oxide film layer contains fine particles made of a semiconductor, the light emitting element has a high efficiency utilizing the quantum size effect, and the light emitted by the fine particles is It is confined between the interface between the second silicon crystal layer and the oxide film layer and the interface between the second silicon crystal layer on the side opposite to the oxide film layer. This allows
Light can be efficiently propagated into the second silicon crystal layer.

Further, when light that resonates with the band gap of the fine particles made of the semiconductor enters the second silicon crystal layer, carriers (electrons and holes) are generated in the fine particles made of the semiconductor by optical transition. To do. By outputting this carrier to a predetermined electrode, it becomes possible to convert the optical signal into an electrical signal.

A silicon-based optoelectronic integrated circuit according to one embodiment includes the above-mentioned silicon-based light emitting / receiving element, and the silicon-based light emitting / receiving element constitutes a signal transmission mechanism between semiconductor elements by light.

In the silicon optoelectronic integrated circuit according to this embodiment, the silicon light emitting / receiving element constitutes a signal transmission mechanism between semiconductor elements by light, so that efficient information transmission between the semiconductor elements is possible. Becomes

The silicon-based integrated circuit system of one embodiment comprises the above-mentioned silicon-based light emitting / receiving element, and the silicon-based light emitting / receiving element constitutes a signal transmission mechanism between the integrated circuits by light.

In the silicon-based optoelectronic integrated circuit system of this embodiment, the silicon-based light emitting / receiving element constitutes a signal transmission mechanism between the integrated circuits by light.
Information can be efficiently transmitted between integrated circuits.

In the light emitting and receiving element of one embodiment, in the above silicon based light emitting and receiving element, a silicon oxide film is formed on the second silicon crystal layer.

In the silicon-based light emitting / receiving element of this embodiment, the interface between the silicon oxide film on the second silicon crystal layer and the second silicon crystal layer, and the oxide film under the second silicon crystal layer. Light emitted by the fine particles of the semiconductor is confined between the layer and the interface between the second silicon crystal layer and the light emission can be efficiently propagated in the second silicon crystal layer.

In the silicon-based light-emitting / receiving element of one embodiment, in the silicon-based light-emitting / receiving element, the thickness of the silicon oxide film is smaller than the attenuation distance of light emission in the silicon oxide film.

In the silicon-based light emitting / receiving element of this embodiment, since the thickness of the silicon oxide film is thinner than the light emission attenuation distance of the silicon oxide film, the fact that the refractive index of air is approximately 1 is utilized. Then, the light emitted by the semiconductor fine particles can be more efficiently totally reflected at the interface of the second silicon crystal layer. Therefore, the light propagation efficiency can be further enhanced.

In the silicon-based light emitting and receiving device of one embodiment, a silicon nitride film is formed on the second silicon crystal layer.

In the silicon-based light emitting and receiving element of this embodiment, since the silicon nitride film is formed on the second silicon crystal layer, this silicon nitride film and the second silicon crystal film are formed.
The light emitted from the semiconductor fine particles can be confined between the interface with the silicon crystal layer and the interface between the second silicon crystal layer and the oxide film to efficiently propagate the optical signal.

The silicon-based light emitting / receiving element according to one embodiment is the same as the silicon-based light emitting / receiving element according to the second aspect.
A laminated film of a silicon oxide film and a silicon nitride film is formed on the silicon crystal layer.

In the silicon-based light emitting / receiving element of this embodiment, since the laminated film of the silicon oxide film and the silicon nitride film is formed on the second silicon crystal layer, the film thickness and the number of layers can be reduced. By controlling this laminated film and the second
The reflection at the interface with the silicon crystal layer can be made wavelength dependent, and the waveguiding characteristic can be made dependent on the wavelength of the optical signal propagated in the second silicon crystal layer.

Further, the silicon-based light emitting / receiving element of one embodiment has a control structure for controlling the traveling direction of light in the plane of the second silicon crystal layer.

The silicon-based light emitting / receiving element of this embodiment has a control structure for controlling the traveling direction of light in the plane of the second silicon crystal layer, and thus this control structure is
It can be an optical waveguide for light emission.

Further, in the silicon-based light emitting / receiving element of the one embodiment, in the above silicon-based light emitting / receiving element, the control structure is a trench structure.

In the silicon-based light emitting / receiving element of this embodiment, the control structure of the traveling direction of the light can be constructed by the trench structure.

Further, in the silicon-based light emitting / receiving element of one embodiment, the control structure in the silicon light emitting / receiving element is a LOCOS (local oxidation of silicon) structure.

In the silicon-based light emitting / receiving element of this embodiment, the control structure of the traveling direction of the light can be constructed by the LOCOS structure.

In the silicon-based light emitting / receiving element according to one embodiment, in the silicon-based light emitting / receiving element, the fine particles made of the semiconductor are made of germanium.

In the silicon-based light emitting / receiving element of this embodiment, the fine particles made of the semiconductor are made of germanium. Since germanium is an indirect semiconductor, it has a low emission efficiency, but when it is made into fine particles, it becomes a direct transition type due to the quantum confinement effect, and the emission efficiency becomes high.

Further, in the silicon-based light emitting / receiving element of the one embodiment, in the silicon light emitting / receiving element, the fine particles made of the semiconductor are made of a silicon-germanium mixed crystal semiconductor.

In the silicon-based light emitting and receiving element of this embodiment, the fine particles made of the above semiconductor are made of a silicon-germanium mixed crystal semiconductor, so that the band gap can be controlled not only by the size of the fine particles but also by the mixed crystal ratio.

In the silicon-based light emitting / receiving element of the one embodiment, in the silicon-based light emitting / receiving element, the fine particles made of the semiconductor are compounds such as indium arsenide and indium antimony having a band gap smaller than that of silicon. Made of semiconductor.

In the silicon-based light emitting / receiving device of this embodiment, the fine particles made of the above semiconductor are made of a compound semiconductor of indium arsenide or indium antimony having a band gap smaller than that of silicon. While utilizing the above, the band gap can be controlled by the particle size and the composition ratio of the mixed crystal.

Further, in the silicon-based light-emitting / receiving element of one embodiment, in the silicon-based light-emitting / receiving element, the fine particles made of the semiconductor are made of at least three kinds of elements selected from indium, gallium, arsenic, phosphorus and antimony. It is a mixed crystal compound semiconductor.

In the silicon-based light emitting and receiving device of this embodiment, the fine particles made of the semiconductor are a mixed crystal compound semiconductor composed of at least three kinds of elements of indium, gallium, arsenic, phosphorus and antimony. The band gap can be controlled by the particle size and the composition ratio of the mixed crystal while making the most of the characteristics of the direct transition type semiconductor.

In the silicon optoelectronic integrated circuit according to one embodiment, in the above silicon optoelectronic integrated circuit, a plurality of lights having different wavelengths transmit different signal information, respectively, so that the same optical waveguide is formed. , Wavelength division multiplexing parallel transmission is performed by a plurality of lights having different wavelengths.

In the silicon-based optoelectronic integrated circuit of this embodiment, a plurality of lights having different wavelengths transmit different signal information, respectively, so that a plurality of lights having different wavelengths are wavelength-multiplexed in the same optical waveguide. Perform parallel transmission. Thereby, a plurality of signal information can be transmitted in parallel within the same optical waveguide.

Further, the silicon-based optoelectronic integrated circuit system of one embodiment is the same as the silicon-based optoelectronic integrated circuit system, in which a plurality of lights having different wavelengths transmit different signal information, respectively, so that the same optical waveguide. In the inside, wavelength division multiplexing parallel transmission is performed by a plurality of lights having different wavelengths.

In the silicon-based optoelectronic integrated circuit system of this embodiment, a plurality of lights having different wavelengths transmit different signal information, so that a plurality of signal information can be transmitted in parallel in the same optical waveguide.

The silicon-based optoelectronic integrated circuit of one embodiment is the same as the above-described silicon-based optoelectronic integrated circuit, and is provided with a plurality of silicon-based light emitting / receiving elements, and the plurality of silicon-based light emitting / receiving elements each have a size. The fine particles made of different semiconductors are used, and the plurality of silicon-based light emitting / receiving elements perform wavelength-multiplexed parallel transmission by a plurality of lights having different wavelengths in the same optical waveguide.

In the silicon-based optoelectronic integrated circuit according to this embodiment, the plurality of silicon-based light emitting / receiving elements have fine particles made of semiconductors of different sizes. Thus, it is possible to perform wavelength division multiplexing parallel transmission using a plurality of lights having different wavelengths in the same optical waveguide.

The silicon-based optoelectronic integrated circuit of one embodiment is the same as the above-mentioned silicon-based optoelectronic integrated circuit, and is provided with a plurality of silicon-based light emitting and receiving elements, and fine particles made of semiconductor of the plurality of silicon-based light emitting and receiving elements , A mixed crystal compound semiconductor, and the plurality of silicon-based light emitting / receiving elements each have fine particles made of a mixed crystal compound semiconductor having a different mixed crystal ratio. Wavelength multiplex parallel transmission is performed by a plurality of lights having different wavelengths in the optical waveguide.

In the silicon-based optoelectronic integrated circuit of this embodiment, since the fine particles made of the semiconductor of the plurality of silicon-based light emitting / receiving elements are made of the mixed crystal compound semiconductor, the same silicon-based light emitting / receiving elements are used. Wavelength multiplex parallel transmission can be performed by a plurality of lights having different wavelengths in the optical waveguide.

The silicon-based optoelectronic integrated circuit of one embodiment has an optical waveguide connected to an external system in the above-described silicon-based optoelectronic integrated circuit, and a plurality of light beams having different wavelengths are transmitted via the optical waveguide. Input and output signals by WDM parallel transmission.

In the silicon optoelectronic integrated circuit of this embodiment, an optical waveguide connected to an external system is provided, and signals are input / output through the optical waveguide by wavelength division parallel transmission using a plurality of lights having different wavelengths. can do.

The silicon optoelectronic integrated circuit system of one embodiment is the same as the silicon optoelectronic integrated circuit system, in which an optical waveguide is connected between a plurality of integrated circuits.
Signals are input and output through the optical waveguide by wavelength division parallel transmission using a plurality of lights having different wavelengths.

In the silicon-based optoelectronic integrated circuit system of this embodiment, an optical waveguide is connected between the integrated circuits, and wavelength-multiplexed parallel transmission of a plurality of lights having different wavelengths is performed via the optical waveguide. It is possible to input and output signals.

In the silicon optoelectronic integrated circuit of one embodiment, the optical waveguide is an optical fiber.

In the silicon-based optoelectronic integrated circuit of this embodiment, signals can be input / output by wavelength-multiplexed parallel transmission using a plurality of lights having different wavelengths by using an optical waveguide formed of an optical fiber.

According to another aspect of the present invention, there is provided a method of manufacturing a silicon-based light emitting / receiving element, wherein the silicon-on-insulator layer doped with the first conductivity type is formed on the silicon-on-insulator layer.
A step of forming at least one fine particle made of the semiconductor according to any one of 1. above, and forming an intrinsic silicon epitaxial layer on the doped silicon-on-insulator layer and the fine particle made of the semiconductor, And a step of forming a second conductive type doped silicon layer on the intrinsic silicon epitaxial layer, and a light emitting and receiving device having the silicon on insulator layer and the fine particles of the semiconductor. And a step of forming.

In the method for manufacturing a silicon-based light emitting / receiving element of this embodiment, the fine particles of the above semiconductor are embedded between the silicon-on-insulator layer of the first conductivity type and the intrinsic silicon epitaxial layer, and then the intrinsic silicon epitaxial layer is formed. By forming a second conductivity type doped silicon layer on the layer, a silicon-based light emitting / receiving element having a pin or an nip structure can be manufactured.

In the method for manufacturing a silicon-based light emitting and receiving element according to one embodiment, the intrinsic silicon first epitaxial layer or the silicon on insulator layer is formed on the silicon on insulator layer doped with the first conductivity type. 15. A step of forming a doped silicon first epitaxial layer having the same conductivity type as, and the intrinsic silicon first epitaxial layer or the doped silicon first epitaxial layer, according to any one of claims 11 to 14. The step of forming at least one fine particle made of the semiconductor described above, the intrinsic silicon second epitaxial layer on the intrinsic silicon first epitaxial layer or the doped silicon first epitaxial layer, and the fine particle made of the semiconductor. And forming the fine particles of the semiconductor Forming a second conductivity type doped silicon layer on the intrinsic silicon second epitaxial layer, the silicon-on-insulator layer, the intrinsic silicon first epitaxial layer or the doped silicon first epitaxial layer. A step of forming a silicon-based light emitting / receiving element having a layer, the doped silicon layer, and fine particles made of the semiconductor.

In the method for manufacturing a silicon-based light emitting / receiving element of this embodiment, the intrinsic silicon / first epitaxial layer on the SOI layer (or the doped silicon / first epitaxial layer having the same conductivity type as the SOI layer), and the intrinsic silicon / first epitaxial layer The fine particles made of the semiconductor are embedded between the silicon and the second epitaxial layer, and then the intrinsic silicon and the second epitaxial layer are formed.
A second conductivity type doped silicon layer is formed on the epitaxial layer. As a result, p-i-n or n-i-
A silicon-based light emitting / receiving element having a p-structure can be manufactured.

According to this manufacturing method, fine particles made of a semiconductor are formed on the flat intrinsic silicon first epitaxial layer (or the doped silicon first epitaxial layer) formed on the SOI layer. be able to. This makes it possible to control the distribution of semiconductor particles in the depth direction and reduce surface irregularities and defects.

In the method for manufacturing a silicon-based light emitting / receiving element of one embodiment, a step of forming an n-type region in the undoped silicon-on-insulator layer and a step of forming a p-type region in the undoped silicon-on-insulator layer. A step of ion-implanting a semiconductor into the undoped region between the n-type region and the p-type region, a heat treatment step for forming fine particles of a semiconductor after the ion implantation, the undoped silicon-on-insulator layer and And a step of forming a silicon-based light emitting and receiving element having fine particles made of the above semiconductor.

Since the method of manufacturing the silicon-based light emitting / receiving element of this embodiment is constituted only by the standard manufacturing process of the MOSFET, the MOSF is in view of the manufacturing process.
Good compatibility with ET.

Now, the principle of the present invention will be described. In fine particles made of a semiconductor formed in a silicon substrate, a quantum confinement level is formed in the band gap of silicon. Since the energy of light emission due to the transition between the quantum confinement levels is smaller than the bulk band gap,
It can propagate without being absorbed by bulk silicon.

In the i layer (genuine silicon epitaxial layer),
By combining the p-i-n light emitting element or the light receiving element formed with the semiconductor fine particles and the MOSFET or the bipolar transistor, it is possible to convert an electric signal into an optical signal and an optical signal into an electric signal. Become.

As a result, signals can be transmitted between semiconductor elements in a silicon-based integrated circuit, between integrated circuits, or between an integrated circuit and an external system.

By the way, the fine particles formed in the silicon substrate emit light having energy lower than the band gap of bulk silicon. Therefore, the light emission has an advantage that it can propagate in silicon without being absorbed by bulk silicon. However, for that reason, the above-mentioned light emission propagates in all three-dimensional directions in the bulk silicon, and it becomes impossible to use it instead of the metal wiring between the elements.

Here, Si, SiO ₂ and Si ₂ N ₃
Table 1 summarizes the refractive index and the critical angle. Silicon oxide film (SiO ₂ ) and silicon nitride film (Si ₂ N ₃ )
Has a smaller refractive index than that of silicon (Si).
Therefore, total reflection of light occurs at the interface between silicon and the silicon oxide film or the silicon nitride film. Table 1 shows the calculation of the critical angle (θ _C ) that causes total reflection from Snell's law.

[0067]

[Table 1]

Therefore, at the interface between the silicon layer 91 and the insulating film layer 92 as shown in FIG. 10, when light is incident on the interface at an incident angle larger than the critical angle, the insulating layer 92 of the light is incident.
There is no refracted light component to the silicon region 91, and only the reflected component to the silicon region 91 (total reflection). Therefore, fine particles made of a semiconductor are formed on an SOI (silicon on insulator) layer of an SOI (silicon on insulator) substrate, and a silicon oxide film, a silicon nitride film, or a laminated film of these is formed on the SOI layer. By forming the insulating film, light emission from the fine particles made of semiconductor is confined in the two-dimensional space of the SOI layer sandwiched between the buried oxide film below the SOI layer and the insulating film.

In particular, in the above-mentioned laminated film, reflection can be made wavelength-dependent by controlling the film thickness and the number of layers of each layer. It is possible to have more.

Further, the refractive index of air is approximately n≈1, which is smaller than that of a silicon oxide film or a silicon nitride film. Therefore, the total reflection angle at the interface between silicon and air is also θ.
_It becomes as small as _C ≈ 17.0 °.

Further, it is necessary to form a silicon oxide film as a protective film for the device.

However, if the film thickness of the silicon oxide film is thinner than the exudation of light in the silicon oxide film,
Even when the fact that the refractive index of air is n≈1, it is possible to cause total reflection with high efficiency. In Figure 11,
The electric field intensity distribution 103 of the light confined in the silicon region 101 is shown. The electric field intensity distribution 103 of this light is attenuated in the silicon oxide film region 102. The light seeping distance in the silicon oxide film region 102 is determined by the light wavelength and the incident angle.

Since germanium and silicon-germanium are indirect semiconductors, their luminous efficiency is low. However, when they are made into fine particles, they are of a direct transition type due to the quantum confinement effect, so that the luminous efficiency is increased.

Furthermore, if the fine particles are formed of a compound semiconductor such as gallium / arsenic, since it is originally a direct transition type semiconductor, a light emitting / receiving element with higher efficiency can be formed. If this direct transition type semiconductor is used, it is considered that a highly efficient light emitting and receiving element can be formed even if it is not a particle but a bulk.

However, since most compound semiconductors have different lattice constants from that of silicon, it is difficult to form a stable heterostructure without defects due to lattice mismatch.
On the contrary, by positively utilizing this strain (lattice mismatch), it becomes possible to form fine particles made of a semiconductor in a self-organizing manner. Further, even if there is a lattice mismatch, if the semiconductor fine particles are used, most of the substrate is silicon, so that only a part of the substrate has strain. Therefore, it is possible to form a stable silicon-based light emitting / receiving element. it can.

[0076]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will now be described in detail with reference to the illustrated embodiments.

(First Embodiment: Element Forming Method by Epitaxial Method) With reference to FIGS. 1 and 2, a method of manufacturing a silicon-based light emitting and receiving element will be described as a first embodiment of the present invention.

First, the SOI (silicon) shown in FIG.
The thickness of the on-insulator layer 12 is 30 to 70 n.
An SOI substrate of about m is prepared. This SOI substrate includes a silicon single crystal layer 10, a buried oxide film 11 on the silicon single crystal layer 10, and an SOI layer 1 on the oxide film 11.
2 and.

For this SOI substrate, 30-40 keV
Energy of about 10 ¹⁴ to 1 × 10 ¹⁵ cm ⁻²
For example, an n-type impurity such as arsenic is added to the SO
Ions are implanted into the I layer 12. Since the SOI layer 12 supplies electrons to the fine particles, the final impurity concentration is 1 × 1.
The implantation conditions such as the above energy and dose are adjusted so as to be about 0 ¹⁹ to 1 × 10 ²¹ cm ⁻³ .

Next, a resist (not shown) is applied on the SOI layer 12 so that the film thickness is, for example, 50 to 300 nm. Then, the pattern shape is exposed by an ultraviolet exposure device, and subsequently, this is developed to form a resist pattern (not shown). A silicon oxide film is formed on the SOI substrate by a sputtering method, for example,
It is deposited to a thickness of about 50 to 300 nm. As a result, in the space portion (window portion) of the resist pattern, S
A silicon oxide film is formed on the OI substrate.

Then, by lift-off, only the silicon oxide film deposited on the resist pattern is removed. As shown in FIG. 1A, a mask pattern 13 made of a silicon oxide film is formed on the SOI layer 12. To be done.

Next, by chemical vapor deposition (CVD) method or molecular beam epitaxy (MBE) method, about 1 to 30 nm is applied.
Germanium, for example, is deposited on the SOI substrate. As shown in FIG. 1B, due to the stress caused by the lattice mismatch between the germanium and silicon, the germanium deposited on the SOI substrate does not become a flat thin film, and a crystalline or amorphous island 14 is formed. Are formed on the SOI layer 12 and the mask pattern 13.

The plurality of germanium islands 14 shown in FIG. 1 (B) exist in a state where they are individually separated or in a state where a plurality of them are connected, depending on the size and the number thereof. There are cases. After the island 14 made of germanium is formed, the mask pattern 13 is removed by hydrofluoric acid.

Next, as shown in FIG. 1C, an intrinsic silicon epitaxial layer (i layer) 16 is formed on the SOI substrate by the epitaxial growth method, and the S
The OI substrate is annealed at, for example, about 500 to 700 ° C. As a result, the island 14 is crystallized and germanium particles 15 on the surface of the SOI layer 12 are formed in the intrinsic silicon epitaxial layer 16. The intrinsic silicon epitaxial layer 16 and the SOI layer 12 form a second silicon crystal layer.

Next, the intrinsic silicon epitaxial
An impurity concentration of 1 × 10 is formed on the layer 16. ¹⁹~ 1 x 10²¹
cm^-2Epitaxial layer of p-type silicon layer 17
Then, as shown in FIG. 1 (C), the germanium is contained in the i layer 16.
A p-i-n structure having the fine titanium particles 15 is formed.

By using this embodiment, by forming the semiconductor fine particles 15 on the SOI layer 12, a silicon-based light emitting / receiving element for controlling the propagation direction of light in the two-dimensional SOI layer 12 can be constructed. Become. In addition, as described in a third embodiment to be described later, the silicon-based light emitting / receiving element is
By combining an OSFET or a bipolar transistor, it is possible to transmit information using light at a speed higher than that of electric wiring. The size of the semiconductor fine particles 15 is a size in which the quantum size effect appears, and is on the order of nanometers, for example.

Further, as will be described in the next modification, S
By forming a trench structure or a LOCOS structure in the OI layer 12, the propagation direction of light in the SOI layer 12 can be controlled, and signal transmission between elements can be selectively performed.

(Modification of the First Embodiment) In the first embodiment, the island 14 made of germanium is directly deposited on the SOI layer 12, but the SOI layer 1
The surface of 2 may have irregularities or defects depending on the manufacturing process of the SOI substrate.

In this case, as shown in FIG.
A true (or n-type) silicon epitaxial layer 21 may be epitaxially grown on the OI layer 12, and then the germanium island 14 may be formed on the silicon epitaxial layer 21. In addition, SO
The I layer 12 is formed on the buried oxide film 11, and the buried oxide film 11 is formed on the silicon single crystal layer 10, which is the same as the SOI substrate of FIG. 1 described above.

By thus forming the silicon epitaxial layer 21 on the SOI layer 12, the SO
The surface of the I substrate can be made flat. This makes it possible to control the distribution of the germanium islands 14 in the depth direction and reduce surface irregularities and defects. After that, if the same process as that of the first embodiment is performed, as shown in FIG. 2B, germanium fine particles 15 are formed in the intrinsic silicon epitaxial layer 16 on the silicon epitaxial layer 21. Can form a structure. In this modification, the SOI layer 12 and the epitaxial layers 21 and 16 form a second silicon crystal layer.

In the first embodiment, the SOI layer 1
Although the case where 2 is an n-type has been described, the SOI layer 12
In the case of p-type, a p-i-n structure can be formed by the same method as in the first embodiment by making the doped silicon layer 17 epitaxially grown into n-type.

In the first embodiment, the mask pattern 13 is formed in order to control the position of the fine particles 15 made of germanium. However, since the mask pattern 13 has a laminated pin structure, the mask pattern 13 is not used. Lost, SOI layer 12
It is also possible to form the fine particles 15 made of germanium on the entire surface of the.

In addition, the SOI layer 12, intrinsic silicon
P consisting of the epitaxial layer 16 and the p-type silicon layer 17
After forming the -i-n structure, the trench structure or the LO structure is formed.
The formation of the COS structure also makes it possible to control the distribution of the germanium particles 15 in the plane of the SOI layer 12.

(Second Embodiment) (Device Forming Method by Ion Implantation Method) Next, with reference to FIGS. 3 and 4, a description will be given of a method of manufacturing a silicon-based light emitting and receiving device according to a second embodiment of the present invention. To do.

In the second embodiment, the SOI layer 31 is
An SOI substrate which is doped with impurities of low concentration, which is true or 10 ¹⁷ cm ⁻³ or less, is formed. The impurity is not particularly limited, whether it is n-type or p-type, as long as it has a low concentration.

A resist is formed on the SOI layer 31 shown in FIG. 3A so that the film thickness is, for example, 50 to 300 nm.
Apply (not shown). Then, the resist is exposed to a pattern shape by an ultraviolet exposure device, and subsequently, the resist exposed to the pattern shape is developed,
A resist pattern (not shown) is formed.

Then, a silicon oxide film, for example, 50 to 300 is formed on the SOI substrate by a sputtering method.
Deposit to a film thickness of about nm. In the space portion (window portion) of the resist pattern, on the SOI layer 31 of the SOI substrate,
A silicon oxide film is formed. Then, by lift-off, only the silicon oxide film deposited on the resist pattern is removed to form the mask pattern 32 made of the silicon oxide film. This state is shown in FIG.
It is shown in (A).

Next, as shown by the arrow in FIG. 3A, after p-type impurities such as boron are ion-implanted on the SOI substrate, the mask pattern 32 is removed by hydrofluoric acid. As a result, a region to be the p-type silicon region 33 is formed in the SOI layer 31.

Next, resist patterning is performed on the SOI substrate in the same manner as described above, and then, as shown in FIG.
A mask pattern 34 made of a silicon oxide film is formed as shown in FIG. The mask pattern 34 covers the region to be the p-type silicon region 33 and the region adjacent thereto.

Then, as shown by an arrow in FIG. 3B, an n-type impurity such as arsenic is ion-implanted onto the SOI substrate. As a result, a region to be the n-type silicon region 35, which is separated from the region to be the p-type silicon region 33 by a predetermined dimension, is formed in the SOI layer 31. Then, the SOI substrate is annealed to activate the impurities in the n-type and p-type regions,
As shown in FIG. 3B, a p-type silicon region 33 and an n-type silicon region 35 are formed in the SOI layer 31.

Next, as shown in FIG. 3 (C), a mask pattern 36 is formed by the same method as described above, and germanium ions, for example, 50 as shown by the arrow in FIG. 3 (C) are formed.
Ions are implanted into the SOI substrate with low energy of about keV. Thus, by implanting germanium ions with low energy, the germanium ion-implanted layer 37 is formed. As shown in FIG. 3C, the germanium ion-implanted layer 37 has an SOI
8 nm centered around the depth of about 20 nm from the outermost surface of the layer 31
It is formed in a region having a certain width.

Thereafter, this SOI substrate is, for example, 50
By annealing at about 0 to 700 ° C, S
The germanium ion implantation layer 37 in the OI layer 31 is crystallized. Thereby, as shown in FIG. 4, germanium fine particles 38 are formed from the germanium ion-implanted layer 37.

After the germanium fine particles 38 are formed, the mask pattern 36 is removed with hydrofluoric acid to form a pin structure in the SOI layer 31. The pin structure has a p-type silicon region 33 and an n-type silicon region 35, and a region 39 between the regions 33 and 35.

[0104] In the second embodiment, in the step shown in FIG. 3 (A) and FIG. 3 (B), the p-type impurity ions and the n-type impurity ions, at an energy of about 30~40keV, ^{10 14} ~ Implant with a dose of about 10 ¹⁶ cm ⁻² .

Since it is necessary to supply carriers of electrons and holes to the i layer (region 39) where the fine particles 38 made of germanium are present, it is necessary to supply the p layer (p type silicon region 33) and the n layer.
Final impurity concentration n of the layer (n-type silicon region 35)
_{d is, n} d = 1 × such that ¹⁰ 19 ^~1 × ¹⁰ 21 ^{cm -3} or so, adjusting the injection conditions such as energy and dose of the injection.

At the time when the p-type ion implantation and the n-type ion implantation are finished, activation annealing is performed respectively, so that the p-type germanium fine particles 38 in the i-type region 39 are formed.
-i-n structure is formed.

All of the above ions (p-type ion, n
The same p-i-n structure as described above can also be formed by performing annealing treatment collectively after implantation of (type ions, germanium ions).

In this embodiment, the ion depth distribution of germanium ions implanted into the SOI layer 31 is important. The depth profile of the germanium ion to be implanted is determined by the dose and energy of the ion. SM Sze VLSI Technology 2nd ed. McGra
According to wHill Publishing (1988), the depth profile of ion implantation is the projection range Rp of ions and the projection dispersion ΔR.
From p and the third moment m3, LSS (Lindhar
d, Scharaff, Schiott) theory. J. F. Gibsons, W. S. Johnson, S. M.
By Mylrorie Projected Ranges Statics: Semicond
uctors and Related Materials, 2nd.Dowden, Hut
The chinson & Ross publisher (1975) has compiled a table for Rp and ΔRp and m3 above. SO
With a width of about ΔRp centered on the depth Rp from the outermost surface of the I layer,
A germanium implant layer is formed. By changing the ion implantation energy, the width ΔRp of the implantation layer is changed, and the size of the formed semiconductor fine particles can be controlled. For example, in the case of 30 keV, Rp = 21.8n
m, ΔRp = 8.2 nm.

In the p-i-n structure formed in the first or second embodiment, the light emitting / receiving element capable of injecting carriers from the outside by forming electrodes in the p layer and the n layer. Can be formed. Furthermore, the above p
-i-n structure is formed on the drain region of the MOSFET or on the collector side of the bipolar transistor to form an electrode for supplying a carrier having a polarity opposite to that of the carrier from the drain or the collector, thereby forming electrons and holes By supplying the particles in the layer, the output electric signal of the semiconductor element can be converted into an optical signal. This will be described in detail in the following embodiments.

(Third Embodiment) (Optical Transmission of Signal Between Semiconductor Elements) FIG. 5 shows a third embodiment of the present invention.
1 illustrates a silicon-based optoelectronic integrated circuit as an embodiment. This silicon-based opto-electric integrated circuit is a combination of an npn type bipolar transistor B1 and a pin type light emitting element L1 in which fine particles 15 are formed on an i layer 16. In this silicon-based optoelectronic integrated circuit, the collector 42 of the bipolar transistor B1 and the n-type region 41 of the light emitting element L1 are made common. The collector 42 and the n-type region 41 are formed on the buried oxide layer 11. The buried oxide layer 11 is formed on the silicon single crystal layer 10.

The bipolar transistor B1 in the third embodiment can be formed by the same method as in the first embodiment.

The bipolar transistors B1 and p-i-
A silicon oxide film 48 is provided between the n-type light emitting and receiving element L1.
Is formed, and this silicon oxide film 48 separates the bipolar transistor B1 and the light emitting element L1. A light emitting element metal contact 45 is formed on the p-type silicon layer 17 of the light emitting element L1, and an emitter metal contact 46 is formed on the emitter 44 of the transistor B1.
A base metal contact 47 is formed on the base 43.

The light emitting device L1 has an n-type region 41, an intrinsic silicon epitaxial layer 16 on the n-type region 41, and a p-type silicon epitaxial layer 17 on this epitaxial layer 16, and the intrinsic silicon epitaxial layer 1
6 includes fine particles 15 made of germanium.

Further, the bipolar transistor B1
Is composed of an emitter 44, a base 43, and a collector 42. When a base current flows through the base 43, the bipolar transistor B1 is turned on and the collector 4
Electrons are injected into 2. Then, the electrons are injected into the n-type silicon region 41 of the light emitting element L1, and through the metal contact 45, the p-type silicon region 17 of the light emitting element L1.
When holes are injected into the semiconductor particles 15, the semiconductor fine particles 15 made of germanium in the intrinsic silicon epitaxial layer 16 emit light.

In this embodiment, between the layers 17, 16 and the region 41 of the light emitting element L1 and the corresponding regions (emitter 44, base 43, collector 42) in the depth direction of the bipolar transistor B1. Therefore, the conductivity type and the impurity concentration are different. For example, in the light emitting device L1, the epitaxial layer 16 is genuine silicon, while the base 43 is p-type. Further, while the p-type silicon region 17 of the light emitting element L1 is p-type silicon, the emitter 44 of the bipolar transistor B1 needs to be n-type.

These structures can be manufactured by combining lithography and etching or lift-off. For example, the conductivity type and the impurity concentration of each region can be controlled by forming a mask pattern made of a silicon oxide film and selectively ion-implanting the region without the silicon oxide film.

(Modification of Third Embodiment) Next, FIG. 6 shows a modification of the third embodiment. This modification is n−M
This is a silicon-based optoelectronic integrated circuit in which an OSFET 50 and a pin light emitting element 60 in which semiconductor particles 38 are formed in an intrinsic silicon region (i layer) 31 are integrally incorporated in a semiconductor substrate.

The pin light emitting device 60 includes an n-type region 53, an intrinsic silicon region 31, and a p-type region 35 formed on the buried oxide layer 11 on the silicon single crystal layer 10.
The intrinsic silicon region 31 contains semiconductor fine particles 38. A metal contact 57 is formed on the p-type region 35.

The n-type region 53 shown in FIG. 6 is an n-MOSF.
The drain region 53 of the ET 50 and the n-type region 53 of the light emitting element 60 play two roles.

The MOSFET 50 of this modification can be formed by the same method as that described in the second embodiment. This MOSFET 50 has a source region 51 and a channel region 5
2, a drain region 53, a gate oxide film 54, and a gate electrode 55. When a voltage is applied to the gate electrode 55, the MOSFET turns on and electrons are injected into the drain region 53. Electron is n-type region 53
From the metal contact 57 into the intrinsic silicon region 31 through the p-type region 35 of the light emitting element 60, the semiconductor fine particles 38 in the intrinsic silicon layer 31 emit light. To do.

In the third embodiment and its modification, the combination of the npn bipolar transistor B1 and the light emitting element L1 and the n-MOSFET 50 are used.
The combination of the light emitting element 60 with the
The -np type bipolar transistor or p-MOSFET and the light emitting element L1 or 60 may be combined. In this case, it can be configured by exchanging the conductivity type of each region.

Contrary to the above description, the above FIG. 5 and FIG.
In the p-i-n structure of the light emitting device L1, 60 shown in
Fine particles 1 made of semiconductor formed in the i layers 16 and 31
When light that resonates with the band gaps of 5, 38 enters, electrons and holes are generated in the fine particles 15, 38 by optical transition. As a result, the p-i included in the light emitting elements L1 and 60 are
-n-type n-type regions 41, 53 or p-type regions 17,
It is possible to take out the carrier from 35, and one carrier may be made to flow to another transistor through the electrode.

Furthermore, by incorporating the pin structure into the emitter 44 side of the bipolar transistor B1 shown in FIG. 5 or the source 51 side of the MOSFET 50 shown in FIG. 6, the bipolar transistor B1 or the MOSFET 50 is turned on. Only in the case of, it becomes possible to convert the optical signal into an electrical signal.

The signal conversion function from this light to an electrical signal is
In the structure shown in FIG. 5, the bipolar transistor B1
This can be realized by exchanging the emitter 44 and the base 43 of the. Further, the structure shown in FIG. 6 can be realized by exchanging the source 51 and the drain 53 of the MOSFET 50.

By the way, in particular, in the method for manufacturing a silicon-based light emitting / receiving element of the first embodiment described above, since the silicon-based light emitting / receiving element is configured only by the standard manufacturing process of the bipolar transistor, Good compatibility in terms of manufacturing process. Therefore,
According to the manufacturing method of the first embodiment described above, the bipolar transistor B1 and the light emitting / receiving element L1 in the third embodiment can be simultaneously formed in parallel in the same process.

The manufacturing method of the second embodiment described above is
Since it is constituted only by the standard manufacturing process of the MOSFET, it is compatible with the MOSFET in terms of the manufacturing process. Therefore, according to the manufacturing method of the second embodiment described above, the MOSFET 50 and the light emitting / receiving element 60 in the modified example can be simultaneously formed in parallel in the same process.

Furthermore, due to the progress of fine processing, a process similar to that of MOSFET, which uses lithography and ion implantation, is now being considered in the manufacturing process of a bipolar transistor instead of the conventional epitaxial process. Therefore, with the progress of this manufacturing process in the future, the manufacturing method of the second embodiment is likely to be compatible with the manufacturing process of the bipolar transistor.

(Fourth Embodiment) (Control of Light Propagation Direction by Trench Structure or LOCOS Structure) In the light emitting and receiving elements formed in the first and second embodiments, the light from the light emitting element is emitted from the SOI layer 12 , 31
Propagate in the plane of. However, in the SOI layers 12 and 31,
It has no in-plane directionality. Therefore, this SOI layer is
To use for wiring between elements, as described below,
It is necessary to give directionality to the SOI layer.

That is, by using a lithography technique and a patterning technique using etching or lift-off, a trench is formed in the SOI layer to form a one-dimensional structure. Next, the manufacturing method of the first or second embodiment is executed to form a light emitting / receiving element. Accordingly, it is possible to give directionality to the light propagation direction in the two-dimensional space of the SOI layer.

The light propagation direction can also be controlled by making the SOI layer one-dimensional by using a LOCOS structure that oxidizes the SOI layer region other than the waveguide region instead of the trench structure. .

Further, the propagation direction of light can also be controlled by first forming a trench or a LOCOS structure in the SOI substrate formed by executing the manufacturing method of the first or second embodiment described above. It is possible.

FIG. 7 shows a plane cross section of the SOI layer of an integrated circuit having an element incorporating the light emitting / receiving element formed in the first or second embodiment, as seen from above the substrate.

This integrated circuit has two MOSFETs 60.
1 and 602, and MOSFETs 601 and 602
Are connected by an optical waveguide 631. Then, a trench structure is formed in a region other than the optical waveguide 631,
Deposit an oxide film. Alternatively, a LOCOS structure is formed in a region other than the optical waveguide 631.

As a result, as shown in FIG. 7, the two MOSFETs 601, 602 coupled by the optical waveguide 631 are connected.
Is formed. In FIG. 7, a region 632 other than the optical waveguide 631 and the two MOSFETs 601 and 602.
Is a silicon oxide film.

The n-channel MOSFET 601 has a source region 611, a channel region 612 and a drain region 613.
The n-channel MOSFET 602 includes a source region 621, a channel region 622, and a drain region 623. The drain region 613 of the FET 601 also serves as the n-type region 613 of the light emitting / receiving element 603. Also, F
The drain region 623 of the ET 602 is the light emitting / receiving element 60.
4 also serves as an n-type region 623.

The light emitting / receiving element 603 has the n-type region 613, the p-type region 615 and the light emitting region 614, and the light emitting / receiving element 604 has the n type region 623, the light receiving region 624 and the p type region 625. And have.

An electrode as shown in FIG. 5 is formed on each area. That is, the MOSFET 60
A gate electrode is formed on the channel regions 612 and 622 of the 1,602 via a gate oxide film, and the source region 61 is formed.
A source electrode is formed on 1,621.

In the integrated circuit of the fourth embodiment, the above n
When the channel MOSFET 601 is turned on, the light emitting region 614 emits light, and this light propagates through the optical waveguide 631 formed of the SOI layer as indicated by an arrow. Then, this light forms carriers in the light receiving region 624 of the light emitting and receiving element 604 and turns on the n-channel MOSFET 602. In this way, the n-channel MOSFET 6
It is possible to optically propagate information between 01 and the n-channel MOSFET 602.

In the fourth embodiment, two MOs are used.
The integrated circuit in which information is propagated between SFETs by light has been described. In the third embodiment, two MOSFs are used.
If two bipolar transistors are provided in place of the ETs 601 and 602, an integrated circuit that optically propagates information between the two bipolar transistors can be obtained.

(Fifth Embodiment) (Optical Transmission of Signal between Integrated Circuit and System) Light emitting / receiving element manufactured in the first and second embodiments or the silicon-based optoelectronic integrated circuit in the third embodiment. The circuit can be used to convert the output signal of the integrated circuit into light.

As shown in FIG. 8, a groove 73 is formed in an integrated circuit 71 made of an SOI substrate, and the center of the optical waveguide portion inside the outer peripheral circuit of the groove 73 is aligned with the center of the core of the optical fiber 72 for connection. . An optical system such as a lens is introduced into this connecting portion as needed. This optical fiber 7
By using 2, the output signal of the integrated circuit 71 can be output to the outside of the integrated circuit 71 by light.

For example, the integrated circuit system shown in FIG.
The integrated circuits 81 and 82 are connected by the optical fiber 84, and the integrated circuit 82 is connected to the keyboard 85 by the optical fiber 85.

The integrated circuits 81 and 82 are elements incorporating the light emitting and receiving elements produced in the first and second embodiments or silicon-based optoelectronic integrated circuits comprising the integrated circuits of the third embodiment. .

Information can be input to and output from the integrated circuits 81 and 82 through the optical fiber 84.

Similarly, by connecting the optical fiber 85 so that the center of the optical fiber core is aligned with the center of the optical waveguide inside the integrated circuit 85, the light input from the outside to the optical fiber 85 is connected. Signal
With the integrated circuit 85, it can be converted into an electric signal and inputted into the integrated circuit 85. For example,
In FIG. 9, input data from the keyboard 83 is input to the integrated circuit 82 via the optical fiber 85, whereby signals can be input / output between the integrated circuit 82 and an external system. The external system may be a mouse, a computer, a monitor, an audio or the like in addition to the keyboard 83.

With the combination of these two optical fibers 84 and 85, information transmission between the integrated circuits 81 and 82 and between the integrated circuit 82 and an external system (keyboard 83 in the figure) can be performed by light. It will be possible. This increases the information transmission speed.

(Sixth Embodiment) (Parallel Transmission of Signal Information) The band gap of semiconductor fine particles can be controlled by the size of the semiconductor fine particles. Let R be the radius of the semiconductor particles and m be the effective mass of electrons.
_e , the effective mass of holes is m _h, and the approximation in which the wave function of electrons and holes is 0 at the boundary of the semiconductor particles and the effective mass approximation are introduced, the band gap Eg _{mi cro} of the semiconductor particles is , Can be calculated by the following formula.

[0148] ^{_{Eg micro = Eg bulk + h 2}} φ 1 2 / 2μR 2 ... (1) In the expression (1), h is the blank constant, the μ is the reduced mass μ of electrons and holes. μ = m _e m _h / (m _e
+ M _h ), and Eg _bulk is a band gap in the bulk, and φ ₁ = π.

If fine particles are formed of a silicon-germanium mixed crystal instead of germanium, the band gap can be controlled not only by the size but also by the mixed crystal ratio. For example, the bandgap of silicon is Eg _Si and the bandgap of germanium is Eg _Si.
The band gap Eg _SiGe of silicon-germanium can be calculated by the following formula, where _Ge is the composition ratio of Si.

Eg _SiGe = xEg _Si + (1-x) Eg _Ge (2) It is known that the same relation as in the above formula (2) holds in other mixed crystal systems. If the fine particles are formed of a mixed crystal semiconductor composed of at least three kinds of elements among indium, gallium, arsenic, phosphorus and antimony, instead of the compound semiconductor having a composition ratio of an integer ratio, a direct transition type semiconductor can be obtained. It is possible to control the band gap by controlling the particle size and the composition ratio of the mixed crystal while utilizing the above characteristics.

Although it is difficult to transmit a plurality of signal information in parallel on the same wiring with the conventional metal wiring, when light is used as a signal, different signal information is transmitted for each light having a different wavelength. By transmitting, a plurality of signal information can be transmitted in parallel.

For example, according to the third embodiment, the size of the fine particles made of semiconductor and the composition ratio of the mixed crystal are controlled, and the light emitting and receiving elements made of the fine particles having different band gaps are incorporated as the respective elements of the integrated circuit. The light-receiving element portion including the element or the light-emitting element portion is formed in the same SOI waveguide. This makes it possible to simultaneously transmit a plurality of different pieces of signal information in parallel in the common SOI waveguide with light having different wavelengths.

Furthermore, by combining the sixth embodiment and the fifth embodiment, it is possible to input a plurality of optical signals output from the integrated circuit to the outside through a single optical fiber, which is composed of light. Multiple external signals can be input to the integrated circuit with a single optical fiber. Moreover, it becomes possible to input and output information between integrated circuits and between the integrated circuit and an external system with one optical fiber. A plurality of optical fibers may be used, but a signal requiring a few tens to several hundreds of input / output pins for current electrical signals can be input / output with a smaller number of optical fibers.

As described above, according to the optoelectronic integrated circuit system of this embodiment, the input / output signals corresponding to hundreds of input / output pins are externally provided by the optical fibers of which the number is smaller than that. Signal can be input to and output from the integrated circuit to the outside. Therefore, the cost and development burden associated with the arrangement of the pins are reduced, and the wiring of the printed circuit board incorporating the integrated circuit can be simplified. Further, it is possible to input / output an optical signal between the integrated circuit and another integrated circuit or input / output an optical signal between the integrated circuit and an external system.

The manufacturing method of the light emitting and receiving element shown in the first and second embodiments is an example, and the manufacturing method is not limited to this as long as a similar structure is formed. For example, the patterning method is not limited to UV exposure, and SOI MOSFETs having the same structure can be similarly formed by lithography using electron beams, excimer lasers, X-ray lasers, synchrotron radiation, or the like.

Further, in the first and second embodiments, the mask pattern is formed by the combination of photolithography and lift-off, but the mask pattern of the same structure is formed by the combination of photolithography and etching. it can.

In the above embodiments, germanium was taken as an example of the semiconductor constituting the fine particles, but fine particles of another semiconductor having a band gap smaller than that of silicon may be adopted. It can be manufactured by the same manufacturing method as in the above embodiment.

As described above, according to this embodiment, the signal transmission between the semiconductor element, the integrated circuit, the system, and the like is performed by light, so that the speeding up of the semiconductor element due to the development of future fine processing can be coped with. Signal transmission becomes possible, and advanced information processing that requires high processing capability such as image processing can be realized at higher speed. In addition, with a silicon-based light emitting / receiving element manufactured by an extension of the conventional silicon process technology, high-speed and multiple-light information transmission can be performed between elements, between integrated circuits, and between integrated circuits / systems.

[0159]

As is apparent from the above, since the silicon-based light emitting and receiving element of the present invention has fine particles made of a semiconductor in the second silicon crystal layer on the oxide film layer, the quantum size effect is utilized. And the light emitted by the fine particles is emitted from the interface between the second silicon crystal layer and the oxide film layer and the second silicon crystal layer on the opposite side of the oxide film layer. Trapped between the interface and. As a result, light can be efficiently propagated into the second silicon crystal layer.

When light that resonates with the band gap of the fine particles made of the semiconductor enters the second silicon crystal layer, carriers (electrons and holes) are generated in the fine particles made of the semiconductor by optical transition. . By outputting this carrier to a predetermined electrode, it becomes possible to convert the optical signal into an electrical signal.

The silicon-based optoelectronic integrated circuit of one embodiment includes the above-described silicon-based light emitting / receiving element, and the silicon-based light-emitting / receiving element constitutes a signal transmission mechanism between semiconductor elements by light. Information can be efficiently transmitted between the elements.

Further, in the silicon-based integrated circuit system of one embodiment, the above-mentioned silicon-based light emitting / receiving element constitutes a signal transmission mechanism between the integrated circuits by light, so that efficient information transmission between the integrated circuits is possible. Becomes

Further, in the light emitting / receiving element of one embodiment, a silicon oxide film is formed on the second silicon crystal layer. In this silicon-based light emitting / receiving element, the interface between the silicon oxide film on the second silicon crystal layer and the second silicon crystal layer, the oxide film layer under the second silicon crystal layer, and the second silicon crystal layer are formed. Between the interface with the silicon crystal layer,
Since the fine particles made of the semiconductor confine the emitted light, the emitted light can be efficiently propagated into the silicon crystal layer.

Further, in the silicon-based light emitting / receiving element of one embodiment, since the thickness of the silicon oxide film is smaller than the attenuation distance of light emission in the silicon oxide film, the refractive index of air is approximately 1. By utilizing, the light emitted from the semiconductor fine particles can be more efficiently totally reflected at the interface of the second silicon crystal layer. Therefore, the light propagation efficiency can be further enhanced.

In the silicon-based light emitting / receiving element of the one embodiment, since the silicon nitride film is formed on the second silicon crystal layer, the silicon nitride film and the second silicon crystal layer are formed. The light emitted by the semiconductor fine particles can be confined between the interface of 1) and the interface of the second silicon crystal layer and the oxide film to efficiently propagate the optical signal.

Further, in the silicon-based light emitting and receiving element of one embodiment, since the laminated film of the silicon oxide film and the silicon nitride film is formed on the second silicon crystal layer, the thickness of each layer and the number of layers are set. By controlling, the reflection at the interface between this laminated film and the second silicon crystal layer can be made wavelength dependent, and the wavelength dependence of the optical signal propagated in the second silicon crystal layer can be obtained. Can have wave characteristics.

Further, the silicon-based light emitting and receiving element of one embodiment has a control structure for controlling the traveling direction of light in the plane of the second silicon crystal layer, and thus this control structure is used as an optical waveguide for light emission. be able to.

In the silicon-based light emitting / receiving element of one embodiment, the control structure is a trench structure. In this silicon-based light emitting and receiving element, with the above trench structure,
The control structure of the traveling direction of the light can be constructed.

In the silicon-based light emitting / receiving element of the one embodiment, the control structure is a LOCOS structure. In this silicon-based light emitting / receiving element, a control structure for the traveling direction of the light can be constructed with the LOCOS structure.

Further, in the silicon-based light emitting and receiving element of one embodiment, the fine particles made of the semiconductor are made of germanium. Since germanium is an indirect semiconductor, it has a low emission efficiency, but when it is made into fine particles, it becomes a direct transition type due to the quantum confinement effect, and the emission efficiency becomes high.

In the silicon-based light emitting and receiving device of one embodiment, since the fine particles made of the semiconductor are made of a silicon-germanium mixed crystal semiconductor, the band gap is controlled not only by the size of the fine particles but also by the mixed crystal ratio. it can.

Further, in the silicon-based light emitting and receiving element of one embodiment, since the fine particles made of the above semiconductor are made of a compound semiconductor such as indium arsenide or indium antimony having a band gap smaller than that of silicon, the direct transition type is used. The band gap can be controlled by the particle size and the composition ratio of the mixed crystal while making the most of the characteristics of the semiconductor.

Further, in the silicon-based light emitting and receiving element of one embodiment, the fine particles made of the above semiconductor are at least 3 out of indium, gallium, arsenic, phosphorus and antimony.
Since it is a mixed crystal compound semiconductor composed of more than one kind of element, the band gap can be controlled by the particle size and the composition ratio of the mixed crystal while making the most of the characteristics of the direct transition type semiconductor.

In the silicon-based optoelectronic integrated circuit according to the embodiment, a plurality of lights having different wavelengths transmit different signal information, so that a plurality of lights having different wavelengths are generated in the same optical waveguide. WDM parallel transmission is performed. Thereby, a plurality of signal information can be transmitted in parallel within the same optical waveguide.

In the silicon-based optoelectronic integrated circuit system according to the embodiment, a plurality of lights having different wavelengths transmit different signal information, so that a plurality of signal information are transmitted in parallel in the same optical waveguide. it can.

Further, in the silicon-based optoelectronic integrated circuit according to the embodiment, the plurality of silicon-based light emitting / receiving elements have fine particles made of semiconductors having different sizes. Depending on the light receiving element,
Wavelength multiplex parallel transmission can be performed by a plurality of lights having different wavelengths in the same optical waveguide.

Further, in the silicon optoelectronic integrated circuit of one embodiment, since the fine particles made of the semiconductor of the plurality of silicon light emitting / receiving elements are made of the mixed crystal compound semiconductor, the plurality of silicon light emitting / receiving elements are Wavelength multiplex parallel transmission can be performed by a plurality of lights having different wavelengths in the same optical waveguide.

Further, the silicon optoelectronic integrated circuit of one embodiment has an optical waveguide connected to an external system, and a signal is transmitted through the optical waveguide by wavelength-multiplexed parallel transmission by a plurality of lights having different wavelengths. Can be input and output.

Further, in the silicon optoelectronic integrated circuit system of one embodiment, an optical waveguide is connected between a plurality of integrated circuits, and wavelength multiplexing parallel transmission of a plurality of lights having different wavelengths is performed via the optical waveguide. , Can input and output signals.

Further, in one embodiment, signals can be input / output by wavelength-multiplexed parallel transmission using a plurality of lights having different wavelengths using an optical waveguide formed of an optical fiber.

Further, in the method for manufacturing a silicon-based light emitting and receiving element according to one embodiment, the fine particles made of a semiconductor are embedded between the first conductivity type silicon-on-insulator layer and the intrinsic silicon epitaxial layer, and then the intrinsic silicon is formed. By forming a second conductivity type doped silicon layer on the epitaxial layer, a silicon-based light emitting / receiving element having a pin or nip structure can be manufactured.

Further, in the method for manufacturing a silicon-based light emitting / receiving element of one embodiment, an intrinsic silicon / first epitaxial layer on the SOI layer (or a doped silicon / first epitaxial layer of the same conductivity type as the SOI layer) is formed. , The intrinsic silicon / second epitaxial layer is filled with fine particles of the above semiconductor, and then the intrinsic silicon /
A second conductivity type doped silicon layer is formed on the second epitaxial layer. As a result, p-i-n or n
-A silicon-based light emitting / receiving device having an ip structure can be manufactured.

Further, according to this manufacturing method, fine particles made of a semiconductor are formed on the flat intrinsic silicon first epitaxial layer (or the doped silicon first epitaxial layer) formed on the SOI layer. be able to. This makes it possible to control the distribution of semiconductor particles in the depth direction and reduce surface irregularities and defects.

Further, since the method for manufacturing the silicon-based light emitting / receiving element of the embodiment is constituted only by the standard manufacturing process of the MOSFET, in terms of the manufacturing process, MO
Good compatibility with SFET.

[Brief description of drawings]

1 (A) to 1 (C) are schematic cross-sectional views showing a method of manufacturing a silicon-based light emitting / receiving element (a method of forming fine particles by an epitaxial method) according to a first embodiment of the present invention in the order of steps. Is.

2 (A) and 2 (B) are schematic cross-sectional views illustrating a modified example (a method of forming fine particles by an epitaxial method) of the first embodiment.

3 (A) to 3 (C) are schematic cross-sectional views sequentially showing a method of manufacturing a silicon-based light emitting / receiving element (a method of forming fine particles by an ion implantation method) according to a second embodiment of the present invention. Is.

FIG. 4 is a sectional view of an SOI substrate having an SOI layer 31 having a p-i-n structure manufactured in the second embodiment.

FIG. 5 is a sectional view showing the structure of a silicon-based optoelectronic integrated circuit including a silicon-based light emitting / receiving element (an example in which a light emitting element is incorporated in a bipolar transistor) according to a third embodiment of the present invention.

FIG. 6 is a cross-sectional view showing a structure of a modified example of the third embodiment (an example in which a light emitting element is incorporated in a MOSFET).

FIG. 7 is a plan sectional view showing the structure of a silicon-based optoelectronic integrated circuit according to a fourth embodiment of the present invention.

FIG. 8 is a perspective view showing a connection between an optical fiber and an integrated circuit included in the silicon-based optoelectronic integrated circuit system according to the fifth embodiment of the present invention.

FIG. 9 is a schematic diagram showing a connection by an optical fiber in the system of the fifth embodiment.

FIG. 10 is a schematic diagram showing a state of total reflection at a silicon / insulating film interface.

FIG. 11 is a schematic diagram showing the electric field intensity distribution of light at the silicon / silicon oxide film interface.

FIG. 12 is a schematic cross-sectional view showing the structure of a conventional silicon-based light emitting and receiving element.

[Explanation of symbols]

11 ... Buried oxide film, 12 ... N-type SOI layer, 13 ... Mask pattern made of silicon oxide film, 14 ... Germanium island, 15 ... Germanium fine particles, 16 ... Intrinsic silicon epitaxial layer, 17 ... P-type silicon.
Epitaxial layer, 21 ... Silicon epitaxial layer
(Intrinsic or n-type), 31 ... SOI layer, 32 ... Mask pattern, 33 ... N-type silicon region, 34 ... Mask pattern, 35 ... P-type silicon region, 36 ... Mask pattern,
37 ... Germanium ion-implanted layer, 38 ... Germanium fine particles, 41 ... Light emitting element section n-type region, 42 ... Collector section n-type region, 43 ... Base, 44 ... Emitter, 45 ...
Light emitting element part metal contact, 46 ... Emitter metal contact, 47 ... Base metal contact, 48 ... Silicon oxide film, 51 ... Source (n type), 52 ... Channel region (p
Type), 53 ... Drain and light emitting element section n-type area common area, 54 ... Gate oxide film, 55 ... Gate electrode, 56 ... Source metal contact, 57 ... Light emitting element section p-type area metal contact, 611 ... Source area, 612 Channel region, 613 ... Drain region and light emitting element n-type region, 6
14 ... Light emitting region, 615 ... Light emitting element p-type region, 621 ...
Source region, 622 ... Channel region, 623 ... Drain region and light emitting element n-type region, 624 ... Light emitting region, 62
5 ... Light emitting element p-type region, 631 ... Optical waveguide, 632 ... Silicon oxide film, 71 ... SOI substrate, 72: Optical fiber, 73 ... Groove, 81 ... Integrated circuit, 82 ... Integrated circuit, 83
... keyboard, 84 ... optical fiber, 85 ... optical fiber, 91 ... silicon with refractive index n = 3.42, 92 ... insulating film with refractive index n, 101 ... silicon, 102 ... silicon oxide film, 103 ... electric field intensity of light, 111 ... n + silicon layer, 112 ... first epitaxial layer, 113 ... semiconductor fine particles, 114 ... second epitaxial layer, 115 ... p
+ Epitaxial layer.

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 2H037 AA01 BA02 BA11 DA04 DA06                       DA12 DA16                 5F041 CA05 CA08 CA33 CA57 CA71                       CA74 CB32 CB33 EE01 FF16                 5F089 AA06 AB03 AB15 AC02 AC05                       AC16 CA03 DA02

Claims (24)

[Claims] 1. A substrate having a silicon-on-insulator structure comprising a first silicon crystal layer, an oxide film layer on the first silicon crystal layer, and a second silicon crystal layer on the oxide film layer. Wherein the second silicon crystal layer has fine particles made of a semiconductor. 2. A silicon-based optoelectronic integrated circuit comprising the silicon-based light-emitting / receiving element according to claim 1, wherein the silicon-based light-emitting / receiving element constitutes a signal transmission mechanism between semiconductor elements by light. . 3. A silicon based integrated circuit system comprising the silicon based light emitting and receiving element according to claim 1, wherein the silicon based light emitting and receiving element constitutes a signal transmission mechanism between integrated circuits by light. 4. The silicon-based light emitting / receiving device according to claim 1, wherein a silicon oxide film is formed on the second silicon crystal layer. 5. The silicon-based light emitting / receiving element according to claim 4, wherein the silicon oxide film has a thickness smaller than a light emission attenuation distance of the silicon oxide film. . 6. The silicon-based light emitting / receiving element according to claim 1, wherein a silicon nitride film is formed on the second silicon crystal layer. 7. The silicon-based light emitting and receiving element according to claim 1, wherein a laminated film of a silicon oxide film and a silicon nitride film is formed on the second silicon crystal layer. Light emitting and receiving elements. 8. The silicon-based light emitting and receiving element according to claim 1, further comprising a control structure for controlling a traveling direction of light within the plane of the silicon crystal layer. System light emitting and receiving element. 9. The silicon-based light emitting / receiving device according to claim 8, wherein the control structure is a trench structure. 10. The silicon-based light emitting / receiving element according to claim 8, wherein the control structure is a LOCOS structure. 11. The silicon-based light emitting / receiving element according to claim 1, wherein the fine particles made of a semiconductor are made of germanium. 12. The silicon-based light emitting / receiving element according to claim 1, wherein the fine particles made of a semiconductor are made of a silicon-germanium mixed crystal semiconductor. 13. The silicon-based light emitting and receiving device according to claim 1, wherein the fine particles made of a semiconductor are made of a compound semiconductor of indium arsenide or indium antimony having a band gap smaller than that of silicon. Silicon light emitting and receiving element. 14. The silicon-based light emitting and receiving device according to claim 1, wherein the fine particles made of a semiconductor are a mixed crystal compound composed of at least three or more elements of indium, gallium, arsenic, phosphorus and antimony. A silicon-based light emitting / receiving element, which is a semiconductor. 15. The silicon-based optoelectronic integrated circuit according to claim 2, wherein a plurality of lights having different wavelengths transmit different signal information, respectively, so that a plurality of lights having different wavelengths are transmitted in the same optical waveguide. A silicon-based optoelectronic integrated circuit characterized by performing wavelength division parallel transmission by light. 16. The silicon-based optoelectronic integrated circuit system according to claim 3, wherein a plurality of lights having different wavelengths transmit different signal information, so that a plurality of different wavelengths are provided in the same optical waveguide. A silicon-based optoelectronic integrated circuit system characterized by performing wavelength-division-multiplexed parallel transmission using light. 17. The silicon-based optoelectronic integrated circuit according to claim 15, further comprising a plurality of silicon-based light emitting / receiving elements, wherein each of the plurality of silicon-based light emitting / receiving elements comprises fine particles made of semiconductors of different sizes. A silicon-based optoelectronic integrated circuit having a plurality of silicon-based light-emitting and light-receiving elements for performing wavelength-multiplexed parallel transmission of a plurality of lights having different wavelengths in the same optical waveguide. 18. The silicon-based optoelectronic integrated circuit according to claim 15, further comprising a plurality of silicon-based light emitting / receiving elements, wherein the fine particles made of semiconductor of the plurality of silicon-based light emitting / receiving elements are made of a mixed crystal compound semiconductor. The plurality of silicon-based light emitting / receiving elements have fine particles made of mixed crystal compound semiconductors having different mixed crystal ratios, respectively. A silicon-based optoelectronic integrated circuit characterized by performing wavelength division multiplexing parallel transmission using a plurality of different lights. 19. The silicon-based optoelectronic integrated circuit according to claim 15, further comprising an optical waveguide connected to an external system, and a plurality of different wavelengths being provided via the optical waveguide. A silicon-based optoelectronic integrated circuit characterized by inputting and outputting signals by wavelength division multiplexing parallel transmission using light. 20. The silicon-based optoelectronic integrated circuit system according to claim 16, wherein an optical waveguide is connected between a plurality of integrated circuits, and wavelength multiplexing is performed by a plurality of lights having different wavelengths via the optical waveguide. A silicon-based optoelectronic integrated circuit system, which inputs and outputs signals by parallel transmission. 21. The silicon-based optoelectronic integrated circuit according to claim 20, wherein the optical waveguide is an optical fiber. 22. A method of manufacturing a silicon-based light emitting / receiving element according to claim 1, wherein the silicon-on-insulator layer doped to the first conductivity type is provided. Forming at least one fine particle made of a semiconductor, and forming an intrinsic silicon epitaxial layer on the doped silicon-on-insulator layer and the fine particle made of the semiconductor to form the fine particle made of the semiconductor. Step of burying, step of forming second doped silicon layer of second conductivity type on the intrinsic silicon epitaxial layer, and formation of light emitting / receiving element having fine particles of the silicon-on-insulator layer and the semiconductor A method of manufacturing a silicon-based light emitting / receiving element, comprising: 23. A method of manufacturing a silicon-based light emitting / receiving element according to claim 1, wherein an intrinsic silicon / first epitaxial layer is formed on the silicon-on-insulator layer doped to the first conductivity type, or The step of forming a doped silicon / first epitaxial layer having the same conductivity type as that of the silicon-on-insulator layer; A step of forming at least one fine particle made of the semiconductor described in any one of the above, and an intrinsic silicon on the intrinsic silicon / first epitaxial layer or the doped silicon / first epitaxial layer and the fine particle made of the semiconductor. · Fine particles made of the above semiconductor by forming a second epitaxial layer And a step of forming a second conductive type doped silicon layer on the intrinsic silicon / second epitaxial layer, the silicon-on-insulator layer, and the intrinsic silicon / first epitaxial layer or the doped layer. A silicon first epitaxial layer, the above-mentioned doped silicon layer,
And a step of forming a silicon-based light emitting / receiving element having the fine particles made of a semiconductor. 24. The method for manufacturing a silicon-based light-emitting / receiving element according to claim 1, wherein an n-type region is formed in the undoped silicon-on-insulator layer, and a p-type region is formed in the undoped silicon-on-insulator layer. A step of forming a semiconductor, a step of ion-implanting a semiconductor into an undoped region between the n-type region and the p-type region, a heat treatment step for forming fine particles of a semiconductor after the ion-implantation, the undoped silicon And a step of forming a silicon-based light emitting / receiving element having an on-insulator layer and fine particles made of the above semiconductor.