JP3018001B1 - Combinatorial laser molecular beam epitaxy system - Google Patents

Abstract

An object of the present invention is to provide a combinatorial laser molecular beam epitaxy apparatus for performing an efficient material search in a short time while mainly forming an inorganic superstructure by epitaxial growth for each molecular layer. SOLUTION: A combinatorial laser molecular beam epitaxy apparatus 20 includes a common chamber 22, a growth chamber 24, an annealing chamber 26, a preheating heating chamber 28, and a target load lock chamber 3.
2 and a substrate holder load lock chamber 34. Each of these chambers is a vacuum chamber which is vacuum shielded and independently evacuated to a high vacuum. The growth chamber 24 has a target table 10 loaded with the target 12 and a mask plate 102, facing the substrate holder 48.
An excimer laser beam 13 for vaporizing the target 12;
Reflection high-energy electron diffraction for monitoring in-situ molecular layer epitaxial growth on a thin film growth substrate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a combinatorial laser molecular beam epitaxy apparatus which is used mainly for forming an inorganic superstructure which is epitaxially grown for each molecular layer, and particularly for efficient material search in a short time. .

[0002]

2. Description of the Related Art Recently, a lanthanum / barium / copper oxide superconductor has been discovered, and as the technology for forming a thin film of a high-temperature superconducting oxide has made remarkable progress, various materials such as metallic materials, inorganic materials and organic materials have been developed. The search and research of new functional materials are being conducted. In the formation of high-temperature superconducting oxide thin films, functional oxides such as perovskite are themselves based on multi-component double oxides. It is difficult to predict and optimization must be performed by trial and error.

Under such circumstances, X.M. -D. Xiang et al. Combine thin film formation by multi-source sputtering with mask patterning technology that covers a specific location on a substrate with a mask, and combine oxide high-temperature superconductors by synthesizing a combinatorial thin film of inorganic materials that synthesizes many inorganic substances in parallel. And show that it is effective in searching for functions of multi-dimensional materials (X.-D. Xiang et al., Sciencec).
e., 268, 1738 (1995)).

[0004] Further, G. Briceno et al, for the search of colossal magnetoresistance (CMR) materials, new materials for the cobalt oxide based _{Ln x M y CoO 3- δ (} Ln =
La, Y, M = Ba, Sr, Ca, and Pb) were sputter deposited 128 samples of different compositions in combinatorial synthesis, by measuring the magnetic resistance after sintering in an oxygen atmosphere, based CoO ₂ It was clarified that the composite oxide of the present invention also showed a maximum magnetoresistance ratio of 72% CMR, and only two combinatorial syntheses with different sintering conditions resulted in a Co-based CMR.
Finding and optimizing materials.

[0005]

However, in the combinatorial synthesis of the above-mentioned inorganic materials, since the thin films are all formed at room temperature, they only play the role of controlling the composition. However, combinatorial synthesis of a thin film having a superlattice structure formed by epitaxial growth for each molecular layer has not yet been realized.

Accordingly, the present invention has been made in view of the above problems,
It is an object of the present invention to provide a combinatorial laser molecular beam epitaxy apparatus for forming an inorganic superstructure mainly by epitaxial growth for each molecular layer, and for performing efficient material search in a short time.

[0007]

According to a first aspect of the present invention, there is provided a combinatorial laser molecular beam epitaxy apparatus comprising: a heating means for heating a substrate;
A substrate holder that holds and rotates one or more substrates and transports them to a growth position, a plurality of different solid material targets that are vaporized by excimer laser irradiation, and a rotating and up-and-down operation in which the targets are loaded and the targets are arranged at positions facing the substrates. A movable target table, a movable mask plate disposed between the target and the substrate, a gas supply means for supplying a gas to the substrate surface, and an in-situ epitaxial growth for each monolayer on the substrate surface. Equipped with a high-vacuum chamber capable of controlling the reflected high-speed electron beam diffraction to be observed,
A multilayer film having a different combination of elements and a different lamination sequence in one or both of the substrate and a predetermined region of the substrate is systematically synthesized by epitaxial growth for each molecular layer based on reflection high-speed electron diffraction.

Further, the invention according to claim 2 is characterized in that the mask plate has a plurality of mask patterns, is rotatable and vertically movable, and sequentially exchanges different mask patterns. According to a third aspect of the present invention, the mask plate is a movable mask of a shutter capable of moving horizontally with respect to the substrate, and one or both of the substrate and a predetermined region of the substrate is covered or removed by the movable mask. It is a feature. Further, the invention according to claim 4 provides:
The substrate is α-Al ₂ O ₃ , YSZ, MgO, SrTiO
₃ , LaAlO ₃ , NdGaO ₃ , YAlO ₃ , LaS
rGaO ₄ , NdAlO ₃ , Y ₂ O ₅ , SrLaAlO
₄ , CaNdAlO ₄ , Si or a compound semiconductor. In the invention according to claim 5, the solid material of the target is a high-temperature superconductor, a luminescent material,
It is one of a dielectric, a ferroelectric, a giant magnetoresistive material and an oxide. The oxide may be either a single component or a multi-component. Further, the invention according to claim 6 is characterized in that the substrate is a substrate in which the surface of the substrate is flattened at the atomic level and the outermost atomic layer is specified. According to a seventh aspect of the present invention, there is provided a target load lock chamber for loading a target while maintaining a high vacuum on a target table in the high vacuum chamber. The invention according to claim 8 further comprises, in addition to the high vacuum chamber, a common chamber, an annealing chamber for annealing the substrate after the growth of the thin film, and a residual heat heating for heating the substrate at a high vacuum and a predetermined temperature before the growth of the thin film. Wherein a heating means and a substrate holder are integrally rotated in a common chamber, and rotated and transported to a growth chamber, an annealing chamber and a preheating heating chamber, and independently vacuum-sealed to form a vacuum chamber. It is. The invention according to claim 9 is characterized in that the common chamber is provided with a substrate holder load lock chamber for exchanging the substrate holder while maintaining a high vacuum. Further, the invention according to claim 10 is characterized in that the heating means is a lamp heater, and a substrate holder is arranged at a focal position of the lamp heater.

In the combinatorial laser molecular beam epitaxy apparatus according to the present invention having the above-mentioned structure, [multiple materials] × [multiple substrates] × [mask pattern] ×
Independently controlling the combination of [reaction parameters such as temperature, pressure, and flux (deposition rate) from the gas phase], it is possible to systematically synthesize a superlattice structure epitaxially grown for each monolayer by a series of reactions. it can. According to the inventions described in claims 4 and 5, since the fact that the raw material composition of the target is faithfully supplied to the substrate surface and the adhesion probability is approximately 1 irrespective of the components works advantageously, the thin film epitaxially grown for each monolayer is advantageous. High temperature superconductors, luminescent materials, dielectrics, ferroelectrics, and giant magnetoresistive materials. Furthermore, in the invention according to claim 6, it is possible to observe the RHEED oscillation that is much more regular and long-lasting, so that the epitaxial growth that proceeds for each monolayer can be reliably realized. In the inventions according to the seventh and ninth aspects, since the high vacuum load lock chamber is provided, the substrate and the target can be exchanged in a clean state without being exposed to the atmosphere. Further, according to the present invention, the substrate holder can be rotated and transported while being heated, and the temperature control and the pressure control of the annealing chamber, the preheating heating chamber and the ultrahigh vacuum chamber can be performed independently. According to the tenth aspect of the present invention, the substrate can be heated in an oxidizing atmosphere, for example, when a high-temperature superconducting thin film in which the amount of oxygen greatly affects the characteristics, and infrared rays are focused on the substrate holder, thereby making the substrate effective. Heating.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on embodiments shown in the drawings. FIG. 1 is an external view of a combinatorial laser molecular beam epitaxy apparatus according to an embodiment of the present invention. The combinatorial laser molecular beam epitaxy apparatus 20 according to the present embodiment includes a common chamber 2
2, a growth chamber 24, an annealing chamber 26, a preheating heating chamber 28, a target load lock chamber 32, and a substrate holder load lock chamber 34. Each of these chambers is a vacuum shielded vacuum chamber which is independently evacuated to a high vacuum. Has become. Although TMP in FIG. 1 is an abbreviation of a turbo molecular pump, it is evacuated by an ultra-high vacuum pump through a gate valve (not shown), and a rotary pump is used as an auxiliary pump.

In each vacuum chamber, pressure can be controlled by adjusting the opening / closing degree of a valve (not shown). Further, a valve and a mass flow meter (not shown) are provided at predetermined locations, and oxygen and dry nitrogen can be introduced at a controlled flow rate. It has become.

The common chamber 22 includes a growth chamber 24 and an annealing chamber 26.
And the opening 4 provided in the preheating chamber 28 and the partition 39
The O-ring 41 is buried in a groove around the opening. Further growth room 2
4. The annealing chamber 26 and the preheating heating chamber 28 are vacuum-shielded and fixedly held to the partition wall 39, respectively.

The common chamber 22 is provided with three substrate heating units 36 in which a substrate holder 48, a substrate holder chucker 45, and a lamp heater 8 (see FIG. 2) are stored in a cylindrical housing 35 in FIG. ing. These substrate heating units 36 are rotatably conveyed by a revolving movement shaft 43 and mounted on a transfer plate 38 which moves in the up-down direction.
5 is vacuum-shielded and held by the flange portion 31. The revolving moving shaft 43 is rotated by the rotating mechanism 60 while the common chamber 22 is vacuum-shielded, and the moving mechanism 7
0 moves in the vertical direction.

The flange portion 33 at the other end of the housing 35
The O-ring 4 embedded in the groove around the opening 42 of the partition 39 when the transport plate 38 moves to the lower end point.
1 and is vacuum-shielded separately from the common chamber 22. At this time, the vacuum chambers formed by the substrate heating units 36, 36, 36, the growth chamber 24, the annealing chamber 26, and the preheating heating chamber 28 are independently evacuated and pressure-controlled, and heated to a predetermined temperature. It is supposed to be.

As shown in FIG. 1, in a substrate holder load lock chamber 34 provided in the common chamber 22 via a gate valve 46, a stocker 49 holding a plurality of substrate holders 48 loaded with the substrates 5 is installed. The substrate holder 48 is loaded on the chuck of the substrate heating unit 36 by a clip 52 that is operated from the outside while the substrate holder load lock chamber 34 is maintained at a high vacuum.

In the target load lock chamber 32 provided in the growth chamber 24 via a gate valve 47, a plate 54 holding a plurality of targets 12 is installed, and the target load lock chamber 32 is evacuated to a high vacuum. Target 1 with clip 56 operated from outside while holding
2 can be loaded on a target table (not shown).

Next, the substrate heating section will be described. FIG.
FIG. 3 is a detailed cross-sectional view of the substrate heating unit, showing a state in which the transport plate has moved to a lower end point and the substrate heating unit is in contact with a partition. As shown in FIG.
Has a cylindrical housing 35 having flanges 31 and 33 at both ends, a lamp holder 82 provided on the center line of the housing, and a lamp heater 8 installed in the lamp holder. A substrate rotation mechanism for causing the substrate to rotate. The lamp heater 8 is provided with a water cooling pipe for safety and temperature control, and is water cooled.

The substrate rotating mechanism includes a substrate holder rotating section 84 provided outside the lamp holder 82, and a substrate holder 48 provided on the rotating section for rotating the lamp heater 8
And a chucker 45 disposed at the focal position of the camera.
A rotation gear 83 is provided on the upper portion of the substrate holder rotating portion 84 and meshes with a gear 85 of a rotation shaft 86. A rotation gear 88 provided at the other end of the rotation shaft 86 is connected to a revolution gear 65. Are engaged. Further, a bearing 87 is provided below the rotating portion of the substrate holder.

Next, the growth chamber will be described. FIG. 3 is an external view of a main part of the growth chamber, showing an independent vacuum chamber consisting of a substrate heating unit and a growth chamber. As shown in FIG. 3, the substrate heating unit 36 contacts a partition (not shown) to form an independent vacuum chamber 100 between the substrate heating unit 36 and the growth chamber 24, and the substrate holder 4 having a plurality of substrates 5.
8 is provided on the substrate holder rotating unit 84 of the substrate heating unit 36 (shown in FIG. 2), and the substrate holder is rotatable. The growth chamber 24 includes a rotatable target table 10 provided facing the substrate holder 48, and a mask plate 102 provided between the substrate holder 48 and the target table 10. The mask plate 102 includes, for example, eight types of mask patterns 1
04 is formed. Although the mask plate shown in FIG. 3 has a disk shape, another example of the mask plate may be a shutter shape movable from both directions with respect to the substrate. In this case, the mask plate may be used as a movable mask in horizontal and vertical directions. It can be moved to.

Further, a plurality of targets 12 of different fixed raw materials loaded on the target table 10, a light source 14 of an excimer laser beam 13 for vaporizing these targets 12, a lens 15 for condensing the laser beams, and a laser Window 16 for introducing light into vacuum chamber 100
And reflection high-energy electron diffraction (hereinafter referred to as "RHE") for monitoring in situ molecular layer epitaxial growth on a thin film growth substrate.
ED ". ) And a screen 17 of RHEED. Target table 10
The mask plate 102 is rotatable and vertically movable while maintaining the degree of vacuum in the growth chamber 24, and has a mask rotation mechanism, a target table rotation mechanism, a mask vertical movement mechanism, and a target table vertical movement mechanism, respectively. I have. In particular, the mask rotation mechanism is precisely controlled by, for example, a stepping motor so as to be movable by controlling the thickness of the thin film growth in a predetermined area.

In the growth chamber 24, a gas supply system (not shown) such as oxygen and a reactive gas supplied by a nozzle or the like is supplied for atmospheric epitaxy for returning to normal pressure and nitrogen or oxidation epitaxy related to high-temperature superconductivity. Z) is provided.

Further, the home position and the rotational position of the substrate holder 48, the mask plate 102 and the target table 10 are managed by a control device (not shown), and the position of the substrate on which the thin film is to be grown is controlled by each rotary mechanism. The type of the mask pattern 104 and the type of the target are selected, and while the epitaxial growth for each monolayer is monitored in-situ by RHEED,
In conjunction with this monitor, the time for irradiating an excimer laser in a pulsed manner is controlled.

As the substrate, α-Al ₂ O ₃ , YSZ, M
gO, SrTiO ₃ , LaAlO ₃ , NdGaO ₃ , Y
AlO ₃ , LaSrGaO ₄ , NdAlO ₃ , Y
₂ O ₅ , SrLaAlO ₄ , CaNdAlO ₄ , Si and compound semiconductors can be used.

RH based on molecular layer epitaxy
In order to detect the EED vibration and monitor the RHEED vibration to control each monolayer to maintain the monolayer epitaxial growth, it is extremely necessary to planarize the substrate surface at the atomic level and specify the outermost atomic layer. is important. For example, the perovskite oxide represented by the general formula of ABO ₃ is A
It is composed of the repetition of atomic layers of O and BO ₂ , but when the outermost surface is AO, when it is BO ₂ , when both coexist,
The growth mode of the film deposited thereon is different.

For example, the SrTiO ₃ polished substrate has a top surface mainly made of TiO ₂ and a surface roughness of several nm. When the SrTiO ₃ (100) substrate is wet-etched with an HF / NH ₃ buffer solution (pH = 4.5), the surface can be flattened at the atomic level, and the outermost atomic layer can be formed on the TiO ₂ surface. In the case of the substrate whose surface is flattened at the atomic level in this manner, RHEED oscillation caused by the growth of each monolayer can be detected. Therefore, in this embodiment, it is preferable to use a substrate in which the surface of the substrate is flattened at the atomic level and the outermost atomic layer is specified.

As the solid material for the target, any solid can be used. For example, YBa ₂ Cu ₃ O
₇ , high-temperature superconductors such as ZnO, (ZnMg) O, (Z
nCd) a light emitting material such as O, SrTiO ₃ , BaTiO
A dielectric or ferroelectric such as ₃ , PZT or (SrBa) TiO ₃ , or a giant magnetoresistive material such as (LaSr) MaO ₃ can be used. Furthermore, it is also possible to supply each component using single component and multicomponent oxides.

Next, the operation of the combinatorial laser molecular beam epitaxy apparatus when forming a thin film will be described.
Referring to FIG. 3, for example, the vacuum chamber 100 is
^The substrate holder 6 is rotated to position the substrate 5 at the growth position while controlling the substrate 5 at a high vacuum of about ^-4 Torr and controlling the substrate 5 at a growth temperature of, for example, 850 ° C. by the lamp heater 8. A mask pattern 104 is selected by a mask rotating mechanism corresponding to the substrate 5, and the target table 10 is rotated to face the substrate 5 at the growth position, and the target 12 is arranged at a predetermined position. The excimer laser light 13 is irradiated, for example, in a pulse shape for a predetermined time.

By the irradiation of the excimer laser light,
Both rapid heat generation and photochemical reaction occur on the surface of the target, and the raw material components explosively evaporate, forming a thin film of the desired composition on the substrate. Further, at the specular reflection point of RHEED, vibrations due to repeated nucleation and flattening due to the growth of each layer can be observed, and a film thickness monitor having strictly self-controllability for each monolayer is performed. After the epitaxial growth for each monolayer, the target table 10 is rotated to place another target 12 at a predetermined position, and a thin film as another superlattice structure is grown.

After producing an artificial crystal or a superlattice having a new lattice structure on one substrate, the substrate holder 6 is rotated to process the next substrate. When the epitaxially grown film is a superconductor, the necessary oxidation conditions are satisfied by increasing the oxygen partial pressure in the growth chamber 24. In this embodiment, the degree of pressure reduction is low, and the oxygen partial pressure in the growth chamber can be controlled in a wide range.

The above is the case where combinatorial synthesis is performed by fixing a mask pattern on multiple substrates, but a mask pattern obtained by sequentially changing and moving different mask patterns on one substrate, that is, moving a mask plate. May be used as a movable mask to form thin films having different compositions or superlattices having different laminated structures in a plurality of predetermined regions. Further, a thin film having a different composition or a superlattice having a different laminated structure may be manufactured by covering or removing a predetermined region of the substrate by using a shutter-shaped mask plate as a movable mask with respect to the substrate.

As described above, in the combinatorial laser molecular layer epitaxy apparatus of the present embodiment, [multiple raw materials] × [multiple substrates] × [mask pattern] × [temperature, pressure, flux (deposition rate) from gas phase, etc. Are independently controlled, and a group of substances whose structures are systematically controlled can be synthesized by one series of reactions.

Next, a rotating mechanism for rotating and transporting the transport plate and a moving mechanism for vertically moving the transport plate will be described. As shown in FIG. 1, a rotation mechanism 6 for rotating the transport plate 38
0 is a motor 61 provided on the moving plate 72;
A shaft 62 for transmitting the rotational driving force of the motor 61
And a drive gear 64 provided at an end of the shaft 62.
The drive gear 64 is configured to mesh with a revolving gear 65 provided on the revolving movement shaft to transmit the power of the rotating machine. The rotating shaft 62 passes through a flexible tube 82 provided between the moving plate 72 and the growth chamber 22 for vacuum shielding.

Referring to FIG. 2, a transport plate 38 is attached to a plurality of fixing shafts 91 at the end of the revolving shaft 43.
A support gear 92 is fixedly provided via a bearing 93, and a revolving gear 65 is provided so as to rotate at a predetermined torque with respect to the support 92 via a bearing 93.

Referring to FIG. 1, a moving mechanism 70 includes a bracket 73 fixed to an upper cover 71 of the common chamber 22, a rotating shaft 75 driven by a motor 74 provided on the bracket 73, and a rotating shaft 75. And a moving plate 72 that moves up and down by the rotation of 75. The revolving moving shaft 42 passes through the inside of a flexible tube 83 provided for vacuum shielding between the moving plate 72 and the growth chamber 22, and is placed on the moving plate 72. Magnetically shielded by the magnetic shield unit 77 fixed to
And it is held rotatably. The magnetic shield unit vacuum shields the revolving shaft with a magnetic fluid.

First, the operation of the moving mechanism will be described. When the moving plate 72 is at the upper starting point, the rotating shaft 75 is rotated by the motor 74 and the moving plate 72 is lowered.
At this time, the flexible tubes 82 and 83 between the moving plate 72 and the upper lid 71 of the growth chamber 22 shrink. As the moving plate 72 moves down, the revolving moving shaft 43 moves down. As the revolving moving shaft 43 moves down, the flange 3 of the substrate heating section 36 provided on the transport plate 38 moves.
3 comes into contact with the O-ring 41, compresses the O-ring 41 and stops. Therefore, each vacuum chamber is vacuum shielded by the substrate heating unit, and can be independently evacuated and controlled in pressure, and can be heated to a predetermined temperature.

Next, the operation of the transport plate and the substrate rotating mechanism will be described. When the moving plate 72 is at the upper starting point, the rotational driving force is transmitted to the shaft 62 by the motor 61 and the driving gear 64 rotates. The drive gear 64 rotates the revolving movement shaft 43 together with the revolving gear 65, and the transport plate rotates with this rotation, so that the substrate heating unit 36 revolves. At this time, since the rotation gear 88 also rotates, the rotation driving force is applied by the rotation shaft 86 to the rotation gear 8.
3, the substrate holder rotating unit 85 rotates, and the substrate holder 48 rotates. The revolving movement shaft 43,
The rotation shaft 62 and the rotation shaft 86 rotate while being vacuum-shielded in each vacuum chamber. Thereby, the substrate heating unit provided on the transport plate can be transported to each vacuum chamber, and the substrate holder can be rotated.

When the transfer plate 38 moves to the lower end point and the substrate heating section is vacuum-shielded separately from the common chamber, the rotational driving force of the rotary shaft 62 is transmitted to the revolving gear 65.
However, since the substrate heating section abuts on the O-ring and is in a locked state, only the revolving gear 65 is mounted on the bearing 93.
, The rotation gear 88 rotates with this rotation, the substrate holder rotating unit 85 rotates, and the substrate holder 48 rotates. Thereby, the substrate holder can be rotated in each vacuum chamber.

Next, the operation in the process of this embodiment will be described. When the transfer plate 38 is at the home position of the upper starting point at room temperature at a predetermined pressure, the first substrate holder 48 is loaded into the chucker 45 of the substrate heating unit corresponding to the preheating chamber, and then the transfer plate 38 is lowered, and each substrate is heated. The portion 36 comes into contact with the O-ring 41 of the partition wall, compresses and stops. The preheating chamber 28 is set to a high vacuum of, for example, 10 ^-6 Torr.
And cleaning, and at a temperature rise rate of 10
The temperature is raised to 950 ° C at a rate of ° C / min.

After a lapse of a predetermined time, each vacuum chamber and the common chamber are returned to a predetermined pressure while maintaining the temperature of each substrate heating unit, and the transfer plate 38 moves to the upper starting point. This transport plate 38 rotates, and the first plate corresponding to the preheat heating chamber 28 is rotated.
The substrate heating section loaded with the substrate holder is transported to the growth chamber 24. At this time, at room temperature, that is, the lamp heater 8
A second substrate holder 48 for performing the next process is loaded in the chuck 45 of the substrate heating unit 36 corresponding to the preheating chamber in the substrate heating unit where is turned off.

The transport plate 38 is lowered to isolate each vacuum chamber, and the growth chamber 24 is kept at a high vacuum of, for example, 10 ^-4 To.
While maintaining the temperature at rr and heating to 950 ° C., laser molecular beam epitaxy is performed for a predetermined time. At this time, the temperature in the preheating heating chamber 28 is maintained at 10 ^-6 Torr,
The temperature is being raised to 950 ° C at a rate of ° C / min.

In the growth chamber 24, a superlattice structure or the like is formed on each substrate by rotating the substrate holder by molecular layer epitaxial growth for each monolayer, and then, while maintaining the set temperature of 950 ° C., the vacuum chamber and the common chamber are subjected to a predetermined pressure. And the transport plate 38 moves to the upper starting point. This transport plate 38
Rotates, and transports the substrate heating unit loaded with the first substrate holder corresponding to the growth chamber 24 to the annealing chamber 26.
At this time, the third substrate holder 48 is loaded in the chucker 45 of the substrate heating unit 36 corresponding to the preheating chamber 28.

The transfer plate 38 is lowered to isolate each vacuum chamber, and annealing is performed at a temperature lowering rate of, for example, 950 ° C. at a rate of 10 ° C./min for a predetermined time while the annealing chamber 28 is maintained at, for example, 1 Torr. In this annealing chamber 28,
The oxygen partial pressure is controlled optimally. Turn on the lamp heater 8
When the annealing chamber 28 is cooled to room temperature, the vacuum chamber and the common chamber are returned to a predetermined pressure while the other substrate heating units are maintained at 950 ° C., and the transfer plate 38 is moved to the upper starting point. The plate 38 rotates and returns to the home position. Then, the substrate holder after the epitaxial growth is taken out and stored in the stocker 49, and a new fourth substrate holder is placed in the chucker 45 of the substrate heating unit 36.
, And sequentially processed.

As described above, in the present embodiment, the combination of [multiple raw materials] × [multiple substrates] × [mask pattern] × [reaction parameters such as temperature, pressure, and flux (deposition rate) from the gas phase] is used. A group of substances whose structures are systematically controlled by one series of reactions can be synthesized independently. Further, a growth chamber 24 for forming a monolayer epitaxial growth layer on the substrate, an annealing chamber 28 for annealing the substrate on which the thin film has been grown, and a residual heat heating chamber 28 for cleaning and heating the substrate are respectively provided in the corresponding substrate heating sections 36, 36, and 3.
Since the pressure control and the temperature control are independently performed together with the pressure control 6, the transfer can be performed without lowering the substrate temperature, and the process at a different substrate temperature and pressure can be continuously performed.

[0044]

As will be understood from the above description, in the combinatorial laser molecular beam epitaxy apparatus of the present invention, [multiple materials] × [multiple substrates] × [mask pattern] ×
Independently controlling the combination of [reaction parameters such as temperature, pressure, and flux (deposition rate) from the gas phase], it is possible to systematically synthesize a superlattice structure epitaxially grown for each monolayer by a series of reactions. It has the effect of being able to.

[Brief description of the drawings]

FIG. 1 is an external view of a combinatorial laser molecular beam epitaxy apparatus according to an embodiment of the present invention.

FIG. 2 is a detailed sectional view of a substrate heating unit according to the embodiment.

FIG. 3 is an external view of a main part of a growth chamber according to the embodiment.

[Explanation of symbols]

Reference Signs List 5 substrate 6 substrate holder 8 lamp heater 10 target table 12 target 13 excimer laser beam 14 light source 15 lens 16 window 17 screen 18 electron gun 19 nozzle 20 combinatorial laser molecular beam epitaxy device 22 common room 24 growth room 26 annealing room 28 preheating room 34 substrate holder load lock chamber 35 housing 36 substrate heating part 38 transfer plate 39 partition 41 O-ring 42 opening 43 revolving movement shaft 45 chucker 48 substrate holder 52 clip 60 rotating mechanism 62 shaft 64 drive gear 65 revolving gear 70 moving mechanism 71 Upper lid 72 Moving plate 73 Bracket 74 Motor 75 Rotating shaft 77 Magnetic seal unit 82 Flexible tube 83 Rotating gear 84 Holder rotating part 85 gear 86 rotates the shaft 87 bearing 88-rotating gear 91 fixed shaft 92 support 93 bearing 100 vacuum chamber 102 mask plate 104 mask pattern

Continuation of the front page (56) Reference US Pat. No. 5,776,359 (US, A) WO 96/11878 (WO, A1) Science 268 (1995) P. 1738-1740 Nature 389 (1997) 944-948 Appl. Phys. Lett. (1997) p. 3353-3355 (58) Field surveyed (Int. Cl. ⁷ , DB name) C30B 23/08 B01J 19/00 H01L 21/203 H01L 43/08 INSPEC (DIALOG) JICST file (JOIS)

Claims (10)

(57) [Claims] 1. A heating means for heating a substrate, a substrate holder for holding one or more substrates and rotating and transporting them to a growth position, a plurality of different solid material targets vaporized by irradiation of excimer laser, and A rotatable and vertically movable target table for loading and disposing the target at a position facing the substrate, a movable mask plate disposed between the target and the substrate, and supplying gas to the substrate surface Gas supply means, and reflection high-speed electron beam diffraction for observing in situ the epitaxial growth of each monolayer on the substrate surface in a high-vacuum chamber capable of pressure control, wherein any of the substrate and a predetermined region of the substrate is provided. Either or both, systematically reflect multi-layer films with different element combinations and lamination sequences depending on the mask plate Fast synthesized by epitaxial growth per molecule layer on the basis of electron diffraction, combinatorial laser molecular beam epitaxy apparatus. 2. The combinatorial laser molecular beam epitaxy according to claim 1, wherein the mask plate has a plurality of mask patterns, is rotatable and vertically movable, and sequentially exchanges the different mask patterns. apparatus. 3. The method according to claim 1, wherein the mask plate is a movable mask of a shutter that is horizontally movable with respect to the substrate, and one or both of the substrate and a predetermined region of the substrate is covered or removed by the movable mask. The combinatorial laser molecular beam epitaxy apparatus according to claim 1, characterized in that: 4. The method according to claim 1, wherein the substrate is α-Al ₂ O ₃ , YSZ, M
gO, SrTiO ₃ , LaAlO ₃ , NdGaO ₃ , Y
AlO ₃ , LaSrGaO ₄ , NdAlO ₃ , Y
_{2 O 5, SrLaAlO 4, CaNdAlO} 4, characterized in that any one of Si and compound semiconductor, combinatorial laser molecular beam epitaxy apparatus according to claim 1. 5. The target according to claim 1, wherein the solid material of the target is any one of a high-temperature superconductor, a luminescent material, a dielectric, a ferroelectric, a giant magnetoresistive material, and an oxide.
3. The combinatorial laser molecular beam epitaxy apparatus according to 1. 6. The combinatorial laser molecular beam epitaxy apparatus according to claim 1, wherein the substrate is a substrate in which a surface of the substrate is flattened at an atomic level and an outermost atomic layer is specified. 7. The combinatorial laser molecule according to claim 1, wherein a target load lock chamber for loading the target while maintaining a high vacuum is provided on the target table in the high vacuum chamber. Line epitaxy equipment. 8. In addition to the high vacuum chamber, a common chamber, an annealing chamber for annealing the substrate after growing the thin film, and a preheating heating chamber for heating the substrate at a high vacuum and a predetermined temperature before growing the thin film are provided. Wherein the heating means and the substrate holder are integrally rotated and conveyed to the growth chamber, the annealing chamber and the preheating heating chamber in the common chamber and vacuum sealed independently to form a vacuum chamber. A combinatorial laser molecular beam epitaxy apparatus according to claim 1. 9. The combinatorial laser molecular beam epitaxy apparatus according to claim 8, further comprising a substrate holder load lock chamber for replacing the substrate holder while maintaining a high vacuum in the common chamber. . 10. The combinatorial laser molecular beam epitaxy apparatus according to claim 1, wherein said heating means is a lamp heater, and said substrate holder is disposed at a focal position of said lamp heater.