JP2002260523A - Field electron emission device with diamond-like carbon multilayer structure - Google Patents

Abstract

(57) Abstract: An electric field electron having a diamond-like carbon multilayer structure having stable field electron emission characteristics by compensating for a defect in the case of a DLC single layer film by using an emitter as a DLC multilayer film. An emission element is provided. SOLUTION: A field emission device having a diamond-like carbon multilayer structure includes an emitter 2 in which a diamond-like carbon film having different properties is formed on a substrate 1 in a multilayer structure.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a field electron emitting device using a DLC thin film, and more particularly to obtaining a field electron emission characteristic having an excellent emitter structure.

[0002]

2. Description of the Related Art Hitherto, an emitter of a field emission device using a DLC has often been used as a single layer.

[0003]

[0008] However, in the case of single-layer film as emitters in the conventional field emission device using the DLC, when changing the film formation conditions for the SP ³ rich,
Field emission is easy, but the current cannot be increased. On the other hand, when SP ^{2 is made} rich, field electron emission is difficult, but there is a problem that the current can be increased.

[0004] Therefore, even if it has a potential capability, it has not yet been put to practical use due to problems such as stability and reproducibility of field electron emission.

In view of the above-mentioned circumstances, the present invention provides a field emission device having a diamond-like carbon multilayer structure having a stable field emission characteristic by compensating for the drawbacks of a single DLC film by using a DLC multilayer film as an emitter. It is intended to provide an element.

[0006]

In order to achieve the above object, the present invention provides: [1] In a field emission device having a diamond-like carbon multilayer structure, a substrate is provided with a diamond-like carbon film having different properties on a substrate. It is characterized by comprising an emitter formed in a structure.

[2] In a field electron emission device having a diamond-like carbon multilayer structure, a film containing a large amount of graphite is formed on a diamond-like carbon film close to a base material of an emitter to form an electric conduction layer and an electron supply conduction channel. It is characterized by doing.

[3] A field emission device having a diamond-like carbon multilayer structure, characterized in that it has a structure in which a film having a large amount of graphite component and a film having a large amount of diamond component are formed in this order from the base material of the emitter. .

[4] In the field emission device having a diamond-like carbon multilayer structure, a diamond-like carbon film containing a large amount of diamond is used as an emitter and used as an igniter in the early stage of field emission.

[5] In a field emission device having a diamond-like carbon multilayer structure, the diamond-like carbon film close to the base material of the emitter is a diamond-like carbon film doped with nitrogen in order to obtain high conductivity. And

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 1 is a cross-sectional view of a field-emission device having a diamond-like carbon multilayer structure according to a first embodiment of the present invention, and FIG. 2 is a view showing the structure of an emitter of the field-emission device. 3 is an enlarged view of a portion A of FIG. This embodiment has a flat emitter structure.

In these figures, 1 is a substrate (silicon substrate), 2 is an emitter, 3 is a first layer film which is a part of the emitter, 4 is a second layer film which is a part of the emitter, and 5 is an insulating film. The layer (SiO ₂ film) 6 is a gate electrode.

As described above, as the first layer film 2 which is a part of the emitter 2 on the substrate 1, the SP containing a large amount of graphite is used.
^{A 2} rich DLC film is formed. The first layer film 2 has high conductivity characteristics and forms an electric conduction layer and an electron conduction channel. On the first layer film 2, a second layer film 4 which is a part of the emitter 2 and contains a large amount of diamond component SP
^{A 3} rich DLC film is formed. These films are formed by CV
D, PD, arc method, laser ablation, and the like can be used.

The second layer film 4 has a low electron affinity that has a good effect on the field electron emission characteristics, and can improve the characteristics at the beginning of the field electron emission.

Further, the graphite component is large SP ² rich DLC film as the first layer film 2 to form the electron supply conduction channel, to facilitate field emission was continued, contribute to a stable field emission.

A factor that greatly affects the field electron emission characteristics is the electron affinity of the emitter material. The electron affinity is the difference in energy from the vacuum level to the bottom of the conduction band, expressed in an energy diagram of a metal, a semiconductor, or the like. In other words, it is the energy required to separate electrons from matter. This value is 4.0 eV for Si.
It is about. That is, when an energy of 4.0 eV is applied to the Si surface, electrons are emitted from the Si surface. In diamonds, this value is said to be negative. That is, the energy of the vacuum level is lower than the bottom of the conduction band. It is known that in order to satisfy this condition, the surface of diamond needs to be terminated by hydrogen. Diamond is an insulator, but exhibits conductivity when its surface is terminated with hydrogen.

[0018] In the present invention, SP ³ rich DLC near the electrical characteristics of the diamond in the electron emission surface Second layer film 4]
Is used. The electron affinity of the SP ³ rich DLC film is reduced to about 1 eV, this result is facilitated electron emission. Furthermore, hydrogenation treatment can be performed on the surface to help secure conductivity and assist in field electron emission.

The conductivity of the first layer film 3 is generally low. As a result, a conductive channel for supplying electrons to the first layer film 3 is required to continue the field electron emission and obtain a large emission current. The first layer film 3 plays this role. First layer film 3
Is doped with nitrogen to obtain high conductivity. As a result of the presence of these two layers, a large current can be continuously emitted by field electrons.

FIG. 3 is a sectional perspective view of a field emission device having a diamond-like carbon multilayer structure according to a second embodiment of the present invention, and FIG. 4 is a sectional view of a manufacturing process of the field emission device. This embodiment has a conical emitter structure.

In these figures, reference numeral 11 denotes a base material, and 12 denotes an emitter, which is a base material layer 1 made of conical silicon.
2A, the first layer film 12B graphite component consisting of more SP ² rich DLC film, the diamond component is great SP
^This is a second layer film 12C made of a ^3- rich DLC film. 1
3 is an insulating layer (SiO ₂ film), and 14 is a gate electrode.

Hereinafter, a method of manufacturing the field emission device will be described.

(1) First, as shown in FIG. 4A, an insulating layer 13 and a gate electrode 14 are sequentially formed on a conductive substrate 11 in advance by a sputtering method or a vacuum evaporation method. Next, a circular hole (gate hole) is formed in the insulating layer 13 and a part of the gate electrode 14 by photolithography and reactive ion etching (RIE) until the conductive substrate 11 is exposed. Etch as follows.

(2) Next, as shown in FIG. 4B, a release layer 15 is formed only on the upper surface and the side surfaces of the gate electrode 14 by oblique evaporation. As a material of the release layer 15, Al, Mg
O and the like are often used.

(3) Next, as shown in FIG. 4C, silicon 16 for the emitter 12 is deposited on the substrate 11 having conductivity by normal anisotropic deposition from the vertical direction. . At this time, as the deposition proceeds, a conical base layer 12A made of silicon constituting a part of the emitter is formed on the conductive substrate 11 at the same time as the opening diameter of the gate hole is reduced.

(4) Next, as shown in FIG. 4D, the release layer 15 is removed by etching.

(5) Next, as shown in FIG. 4 (e), after the release layer 15 'is formed, the graphite component is formed on the base material layer 12A by normal anisotropic vapor deposition from the perpendicular direction. depositing a SP ² rich of the DLC film 17 is larger. At this time, as the deposition proceeds, the opening diameter of the gate hole becomes narrower, and at the same time, the first part forming part of the emitter on the base layer 12A is formed.
The layer film 12B is formed.

(6) Next, as shown in FIG. 4F, the peeling layer 15 'is peeled off by etching.

(7) Next, as shown in FIG. 4 (g), after a release layer 15 ″ is formed, a diamond is formed on the first layer film 12B by normal anisotropic vapor deposition from the vertical direction. component is great SP ³ is deposited rich in the DLC film 18. in this case, the second layer film 12C constituting progresses deposition, a portion of the emitter opening diameter narrows simultaneously on the first layer film 12B of the gate hole To form

(8) Finally, as shown in FIG.
The peeling layer 15 "is peeled off by etching.

The first layer film 12B has high conductivity characteristics and forms an electric conduction layer and an electron conduction channel. The second layer film 12C has a low electron affinity that has a good effect on the field electron emission characteristics, so that the characteristics at the initial stage of the field electron emission can be improved.

These films can be formed by CVD, PD, arc method, laser ablation, or the like.

[0033] Since the above-described configuration, the graphite component is great SP ² rich DLC film as the first layer film 2 is to facilitate field electron emission in the field emission initial, SP ² rich layer stable field emission To contribute.

According to this embodiment, since the above-mentioned multilayer film is formed on the surface of the conical base material layer 12A made of silicon, the field electron emission can be facilitated. That is,
When the electrodes are in the form of protrusions, electric field concentration occurs and field emission can be facilitated.

It should be noted that the present invention is not limited to the above-described embodiment, but various modifications are possible based on the spirit of the present invention, and these are not excluded from the scope of the present invention.

[0036]

As described above, according to the present invention, the following effects can be obtained.

(A) In the field electron emission characteristics which were difficult to realize with the DLC single layer film of the emitter, it was possible to realize a high density of electron emission sites, a stable electron emission, and a large current of electron emission.

(B) A practical field emission display uses a Spindt-type emitter using silicon. However, the present invention has problems that the cost, the manufacturing method are complicated, and it is difficult to increase the size. According to this, an emitter can be manufactured by a low-cost and simple manufacturing method, which can contribute to a reduction in cost and an increase in size of a field emission display.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a field emission device having a diamond-like carbon multilayer structure according to a first embodiment of the present invention.

FIG. 2 is a view showing a structure of an emitter having a diamond-like carbon multilayer structure according to a first embodiment of the present invention.

FIG. 3 is a sectional perspective view of a field emission device having a diamond-like carbon multilayer structure according to a second embodiment of the present invention.

FIG. 4 is a cross-sectional view illustrating a manufacturing process of a field emission device having a diamond-like carbon multilayer structure according to a second embodiment of the present invention.

[Explanation of symbols]

Reference Signs List 1, 11 Base material (silicon substrate) 2 Emitter 3 First layer film constituting emitter 4 Second layer film constituting emitter 5, 13 Insulating layer (SiO ₂ film) 6, 14 Gate electrode 12 Emitter 12A Conical Substrate layer made of silicon 12B SP ² rich DL rich in graphite component
First layer film composed of C film 12C SP rich in diamond component ³ rich DL
The second layer film 15, 15 consisting of C film ', 15 "peeling layer 16 silicon 17 graphite component is large SP ² rich DLC
Film 18 diamond component is often SP ³ rich of DLC
film

 ──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Yoichi Iseri 144-1 Kawamiya, Tagawa City, Fukuoka Prefecture

Claims (5)

[Claims] 1. A field emission device having a diamond-like carbon multilayer structure, comprising an emitter having a diamond-like carbon film having different properties formed in a multilayer structure on a substrate. 2. An electric field having a diamond-like carbon multilayer structure, wherein a film having a large amount of graphite is formed on a diamond-like carbon film close to a base material of an emitter to form an electric conduction layer and an electron supply conduction channel. Electron-emitting device. 3. A field-emission element having a diamond-like carbon multilayer structure having a structure in which a film having a large amount of graphite component and a film having a large amount of diamond component are formed in this order from the base material of the emitter. 4. A field electron emission device having a diamond-like carbon multilayer structure, wherein a diamond-like carbon film containing a large amount of diamond is used as an emitter and used as an igniter in the early stage of field electron emission. 5. A field-emission element having a diamond-like carbon multilayer structure, wherein the diamond-like carbon film near the base material of the emitter is a diamond-like carbon film doped with nitrogen in order to obtain high conductivity.