JPH07326286A - Manufacture of field emission type microcathode - Google Patents

Abstract

PURPOSE:To form a microcathode of a uniform form and height by forming a shock absorbing layer on a conductive layer in pattern work, and forming cathode holes in the conductive layer and an insulation layer. CONSTITUTION:A lower conductive layer 31, an insulation layer 32, and an upper conductive layer 35 comprising a polysilicone film 34 and a tungsten silicide film 36 are formed in order on a substrate 30. On this layer 35, a shock absorbing layer 37 comprising polysilicone film is formed. Next, a resist film 38 is formed on the layer 37, an aperture part 40 is formed by photolithography, and cathode holes 44 are formed by plasma etching. The layer 37 is then eliminated, a removable layer 46 is formed on the film 36, and a cathode forming layer 48 of molybdenum or the like is deposited on the layer 46 by electron beam deposition. Cathodes 50 can thus be formed in a uniform form.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a method for manufacturing a field emission type microcathode which can be used as, for example, a flat panel display or an image pickup device.

[0002]

2. Description of the Related Art Flat-panel displays have been attracting attention in recent years as a substitute for cathode ray tubes as display devices for small computers or word processors, wall-mounted televisions, and the like. Among them, the field emission display (FED) can realize high brightness and high-speed response, and therefore has characteristics superior to those of the currently mainstream liquid crystal displays.

A key technology in the manufacturing process of FEDs is the process of forming field emission microcathodes. The field emission type micro cathode is a cone-shaped acute-angled cathode, but as shown in FIG. 3, it is manufactured by applying the manufacturing process technology of the semiconductor device according to the conventional example.

An outline of a method of manufacturing a field emission type microcathode according to a conventional example will be described with reference to FIG. Figure 3 (A)
As shown in, the tungsten silicide film 3, the silicon oxide film 4, the polysilicon film 6 and the tungsten silicide film 8 are sequentially formed on the silicon substrate 2. A resist film 10 is formed thereon, and the resist film 10 is patterned with a pattern corresponding to the cathode hole by a photolithography method to form an opening 12.

Next, as shown in FIG.
First, the tungsten silicide film 8 and the polysilicon film 6 are R
Etching is performed by IE or the like. Next, using the same resist film 10 as a mask, the silicon oxide film 4 is etched to form a cathode hole 16 as shown in FIG.

Next, as shown in FIG. 2D, the resist film 10 is removed, and as shown in FIG. 2E, an aluminum layer 18 which is a peeling layer is formed on the tungsten silicide film 8. To film. After that, as shown in FIG. 6F, a molybdenum (Mo) layer 22 is formed on the entire surface of the silicon substrate 2 by a sputtering method or a vapor deposition method. At that time, a microcathode 20 having a sharp tip conical tip made of Mo is formed on the tungsten silicide film 3 in the cathode hole 16 formed in the silicon oxide film 4.

After that, as shown in FIG. 1G, when the aluminum layer 18 which is a peeling layer is removed by wet etching, the Mo layer 22 deposited on the aluminum layer 18 is also removed and the inside of the cathode hole 16 is removed. The microcathode 20 remains. After that, a transparent substrate having a phosphor film or a transparent substrate having a transparent conductive film formed thereon is bonded to the silicon substrate 2 in a vacuum state to form an FED or an image sensor.

Electrons are emitted from the microcathode 20 toward the transparent substrate to be bonded by scanning the grid electrode composed of the tungsten silicide film 8 or the like, and functions as an FED or an image pickup device. Therefore, the shape of the microcathode 20, particularly the height, needs to be uniform, and if these are formed unevenly, pixel defects may occur.

[0009]

However, it has been difficult to form these microcathodes with a uniform shape and height by the conventional method for producing microcathodes. The reason will be described below.

What greatly influences the shape of the microcathode is the coverage when the Mo layer 22 is formed by the sputtering method or the like. This coverage is very sensitive to changes in the shape of the tungsten silicide film 8 that is the base of the Mo layer 22. The change in shape of the tungsten silicide film 8 is caused by the opening 12 of the resist film 10 based on the etching process of the silicon oxide film 4 shown in FIGS.
The cause is the tapering of the tape.

That is, by this etching process, the resist film 10 is also etched, the shape of the opening 12 is changed, and a shoulder drop portion or a taper portion is formed in the opening portion of the tungsten silicide film, which causes the microcathode. The problem is that the height or shape of the For example, when the opening of the tungsten silicide film 8 has a tapered shape, as shown in FIG.
2 changes, the time until the opening of the Mo layer 22 closes increases, and the microcathode 20 formed in the cathode hole 16 corresponding to the portion where the opening does not close.
Is higher than other parts.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a method for producing a microcathode capable of forming a microcathode having a uniform shape and height.

[0013]

In order to achieve the above object, a method of manufacturing a microcathode according to the present invention comprises a step of forming at least an insulating layer and then a conductive layer on the surface of a substrate, and the above conductive layer. A step of forming a buffer layer on the
A step of forming a resist film on the buffer layer, a step of patterning the resist film in a predetermined pattern in which a cathode hole is to be formed, and a patterning process using the resist film as a mask, the buffer layer, Forming a cathode hole in the conductive layer and the insulating layer, removing the buffer layer, and in the cathode hole formed in the insulating layer,
Forming a microcathode.

The conductive layer is not particularly limited, and tungsten silicide (WSi), a polysilicon film, a refractory metal silicide such as WSi _x , MoSi _x , TaSi _x , or a refractory metal, or a laminated structure thereof. And the like.

The layer thickness of the buffer layer is preferably 50 to 300 nm. If the thickness of this buffer layer is too large, the aspect ratio for forming the cathode hole increases, which is not preferable. The buffer layer may be composed of any one of a polysilicon layer, an amorphous silicon layer and an aluminum layer. When a buffer layer made of such a material is used, the buffer layer should be removed with HBr or H
It is performed by a gas-based etching process containing I.

Further, the buffer layer may be composed of any one of a silicon oxide layer, a silicon nitride layer and a silicon oxynitride layer. When a buffer layer made of such a material is used, the buffer layer is removed by a wet etching process using HF or the like. When the buffer layer is composed of such an insulating layer, the insulating layer corresponding to the inner wall of the cathode hole can be simultaneously set back when the buffer layer is removed by etching.

[0017]

A resist film is formed on the buffer layer, and the conductive film and the insulating layer located under the buffer layer are etched using the resist film as a mask. At that time, the resist film is also etched, and the side wall of the opening of the buffer layer located thereunder is also removed. However, the side wall of the opening of the conductive layer located below the buffer layer is removed. Protect. As a result, the side wall shape of the opening formed in the conductive layer becomes uniform, and the microcathode can be formed in a uniform shape and height in the subsequent steps.

When removing the buffer layer by etching,
When the insulating layer corresponding to the inner wall of the cathode hole is made to recede at the same time, it is convenient because a short circuit at the time of forming the cathode material can be prevented.

[0019]

The method for producing a microcathode according to the present invention will be described in detail below with reference to the embodiments shown in the drawings.
1 (A) to 1 (G) are cross-sectional views of a main part showing a method of manufacturing a microcathode according to a first embodiment of the present invention, and FIGS.
(G) is an essential part sectional view showing a manufacturing method of a micro cathode according to a second embodiment of the present invention.

First Embodiment In the method of manufacturing a microcathode according to this embodiment, first, as shown in FIG.
The lower conductive layer 31, the insulating layer 32, and the upper conductive layer 35 are sequentially formed. As the semiconductor substrate 30, for example, a single crystal silicon substrate is used. As the lower conductive layer 31,
For example, a tungsten silicide film is used, but not limited to this, other refractory metal silicide, a polysilicon film, an amorphous silicon film, or an impurity diffusion layer formed on the semiconductor substrate 30 may be used. The lower electrode 31 composed of a tungsten silicide film is formed by CVD under the following conditions, for example. As CVD raw material gas, using the and the He WF ₆ and SiH _4, WF ₆ / Si
The flow rate ratio of H ₄ / He is 3/300/500 SCCM, the atmospheric pressure is 70 Pa, and the substrate temperature is 360 ° C.

As the insulating layer 32, silicon oxide formed by CVD or thermal oxidation is used. The insulating layer 32 formed of a silicon oxide film is formed by CVD under the following conditions, for example. TEOS (Tetraethyloxysilane or Tetraethylo) is used as a CVD source gas.
Using rthosilicate, Si (OC ₂ H ₅ ) ₄ ) and O ₂ , the flow ratio of TEOS / O ₂ is 500 / 1000SCC.
M, the atmospheric pressure is 5 Pa, and the substrate temperature is 400 ° C. The layer thickness of the insulating layer 32 is, for example, 1.0 μm.

The upper conductive layer 35 is not particularly limited,
In this embodiment, a polycide film, which is a laminated film of a polysilicon film 34 of n ⁺ conductivity type and a tungsten silicide film 36, is used. This upper conductive layer 35 functions as, for example, a grid of microcathodes.

The thickness of the polysilicon film 34 is, for example, 5
It is 0 nm. Thickness of tungsten silicide film 36
Is, for example, 150 nm. Polysilicon film 34
The tungsten silicide film 36 is formed, for example, by CVD.
To form a film. The polysilicon film 34 is, for example, as follows.
The film is formed under the following conditions. SiH as a CVD source gas
_Four And PH₃ And using, SiH_Four / PH₃ Flow rate is 5
00 / 0.3SCCM, atmospheric pressure 100Pa, substrate temperature
Is the condition of 500 ° C. Tungsten silicide film
The film 36 is formed under the following conditions, for example. CVD raw material
As gas, WF ₆ And SiH_Four And He using WF₆ 
/ SiH_Four / He flow rate ratio is 3/300 / 500SCC
M, ambient pressure 70 Pa, substrate temperature 360 ° C
It is a matter.

In this embodiment, the buffer layer 37 is formed on the upper conductive layer 35. This buffer layer 37 is a layer that is not included in the manufacturing process according to the conventional example, and in the present embodiment,
It is composed of a polysilicon film. The buffer layer 37 made of a polysilicon film is formed by CVD under the following conditions, for example. SiH ₄ and PH ₃ as the CVD source gas
And the flow rate ratio of SiH ₄ / PH ₃ is 500/0.
3SCCM, atmospheric pressure 100Pa, substrate temperature 500 °
It is the condition of C.

Next, the resist film 3 is formed on the buffer layer 37.
8 is formed, and openings 40 are formed in the resist film 38 by a photolithography method in a predetermined pattern corresponding to the cathode holes. The inner diameter of this opening 40 is
It corresponds to the inner diameter of the cathode hole and is, for example, about 0.8 μm.

Next, the semiconductor substrate 30 having the resist film 38 formed thereon is placed in a plasma etching apparatus,
Etching is performed using the resist film 38 as a mask. The plasma etching apparatus is not particularly limited, but for example, a microwave electron cyclotron resonance plasma (ECR) etching apparatus, an induction coil type plasma (ICP) etching apparatus, a helicon wave utilizing plasma etching apparatus, a transformer coupled plasma (TCP) etching apparatus, etc. Can be illustrated.

First, the buffer layer 37, the tungsten silicide film 36 and the polysilicon film 34 are continuously etched under the following conditions using, for example, an ECR etching apparatus. As the etching gas, a mixed gas of Cl ₂ and O ₂ is used, and the flow rate ratio of Cl ₂ / O ₂ is 70/10 SCCM. The atmospheric pressure is 0.4 Pa. The microwave power is 850 W, the radio frequency (RF) power is 40 W, and the substrate temperature is 10 ° C.

Then, as shown in FIG.
For example, the insulating layer 32 is etched under the following conditions.
CHF is used as an etching gas₃ And CH₂ F₂ Mixed with
CHF using combined gas ₃ / CH₂ F₂ Flow rate of 50 /
It will be 10 SCCM. The atmospheric pressure is 0.3 Pa. Well
Also, the microwave power is 850 W, and the high frequency (R
F) The power is 300 W (800 kHz) and the substrate temperature
The degree is -50 ° C.

In the continuous etching of the multilayer film, excessive overetching under high energy conditions causes
The resist film 38 recedes, the side wall of the opening 40 is also shaved, and the buffer layer 37 located thereunder is also partially etched to form a tapered shape. This is the upper conductive layer 3
It is considered that the time for exposing the resist film 38 to the plasma etching is longer than that of the conventional etching technique for forming a contact hole because the same resist film 38 is used to etch the insulating film 32 and the insulating layer 32.
However, in this embodiment, since the buffer layer 37 is provided,
Even the side wall of the opening of the upper conductive layer 35 is not over-etched.

Next, as shown in FIG. 1C, the resist film 38 is removed by resist ashing, and subsequently, as shown in FIG. 1D, the buffer layer 37 is removed. The resist ashing is performed by using 500 SCCM of O ₂ under the conditions of an atmospheric pressure of 3.0 Pa, a substrate temperature of 200 ° C., and a radio frequency (RF) power of 300 W. The buffer layer 37 made of a polysilicon film is removed using HSC of 120 SCCM, an atmospheric pressure of 0.4 Pa, a substrate temperature of -10 ° C, and a high frequency (R).
F) Performed under the condition of power of 300W. Under this condition, only the buffer layer 37 which is a polysilicon film is selectively removed by etching, and the tungsten silicide film 36 of the underlying upper conductive layer 35 is not removed. This is because the tungsten silicide WSi cannot be removed because the vapor pressure of the bromide of W is low. Therefore, at this point, the upper conductive layer 35 without taper or shoulder drop is obtained. As a result, good vertical anisotropic etching is possible.

Next, as shown in FIG. 1E, the tungsten silicide film 36 is formed by using an electron beam evaporation method or the like.
A peeling layer 46 is formed on the above. The peeling layer 46 is composed of, for example, an aluminum metal layer. The peeling layer 4
The layer thickness of 6 is not particularly limited, but is, for example, about 50 nm. The substrate angle during electron beam evaporation is preferably about 20 degrees. The atmospheric pressure is 1.0 Pa, for example.

Next, as shown in FIG. 1F, a cathode forming layer 48 is deposited on the peeling layer 46 by using, for example, an electron beam evaporation method. Molybdenum (Mo) is preferably used for the cathode formation layer 48, but other refractory metals, other metals, compounds, or the like can also be used. The angle of the substrate during electron beam evaporation is
About 90 degrees is preferred. Cathode forming layer 48 is about 1.0 μ
By forming it with a layer thickness of m 2, the surface of the substrate 30 located at the bottom of the cathode hole 44 has a cathode 50 with an acute cone shape.
Are formed with a uniform shape and height. Each cathode 50
The shape, in particular the height, of each of the openings 4 of the cathode formation layer 48 is
It depends on the time until 8a is closed. In the present embodiment, since there is no taper or shoulder drop on the side wall of the opening 40 of the tungsten silicide film 36, each opening 48 is formed.
The time until a is closed is also constant, and the shape, especially the height, of each cathode 50 can be made uniform.

Next, as shown in FIG. 1G, wet etching (about 30 seconds) is performed with hydrofluoric acid at a ratio of water: hydrofluoric acid of about 5: 1, and the peeling layer 46 made of aluminum or the like is used. Are removed by etching, and the cathode forming layer 48 located thereon is lifted off. In the cathode hole 44, the microcathode 20 having a uniform shape and height remains.

After that, a transparent substrate having a phosphor film formed thereon or a transparent substrate having a transparent conductive film formed thereon is laminated on the substrate 30 in a vacuum state to form an FED or an image pickup device. Second Embodiment In this embodiment, a silicon oxide film is used as the buffer film.

The details will be described below. First, FIG. 2 (A)
, The lower conductive layer 3 is formed on the semiconductor substrate 30.
1, the insulating layer 32 and the upper conductive layer 35 are sequentially formed.
As the semiconductor substrate 30, for example, a single crystal silicon substrate is used. As the lower conductive layer 31, for example, a tungsten silicide film is used, but not limited to this,
It may be another refractory metal silicide, a polysilicon film, an amorphous silicon film, or an impurity diffusion layer formed on the semiconductor substrate 30. The lower electrode 31 formed of a tungsten silicide film is C under the following conditions, for example.
It is formed by VD. As a CVD source gas, WF ₆
And SiH ₄ and He, the flow rate ratio of WF ₆ / SiH ₄ / He is 3/300/500 SCCM, and the atmospheric pressure is 70.
The conditions are Pa and the substrate temperature of 360 ° C.

As the insulating layer 32, silicon oxide formed by CVD or thermal oxidation is used. The insulating layer 32 formed of a silicon oxide film is formed by CVD under the following conditions, for example. TEOS and O ₂ are used as the CVD source gas, and the TEOS / O ₂ flow rate ratio is 500/1000 SCCM, the atmospheric pressure is 5 Pa, and the substrate temperature is 400 ° C. The thickness of the insulating layer 32 is
For example, 1.0 μm.

The upper conductive layer 35 is not particularly limited,
In this embodiment, a polycide film, which is a laminated film of a polysilicon film 34 of n ⁺ conductivity type and a tungsten silicide film 36, is used. This upper conductive layer 35 functions as, for example, a grid of microcathodes.

The thickness of the polysilicon film 34 is, for example, 5
It is 0 nm. Thickness of tungsten silicide film 36
Is, for example, 150 nm. Polysilicon film 34
The tungsten silicide film 36 is formed, for example, by CVD.
To form a film. The polysilicon film 34 is, for example, as follows.
The film is formed under the following conditions. SiH as a CVD source gas
_Four And PH₃ And using, SiH_Four / PH₃ Flow rate is 5
00 / 0.3SCCM, atmospheric pressure 100Pa, substrate temperature
Is the condition of 500 ° C. Tungsten silicide film
The film 36 is formed under the following conditions, for example. CVD raw material
As gas, WF ₆ And SiH_Four And He using WF₆ 
/ SiH_Four / He flow rate ratio is 3/300 / 500SCC
M, ambient pressure 70 Pa, substrate temperature 360 ° C
It is a matter.

In this embodiment, the buffer layer 37a is formed on the upper conductive layer 35. The buffer layer 37a is a layer that is not included in the manufacturing process according to the conventional example, and is composed of a silicon oxide film (SiO ₂ ) in this embodiment. The buffer layer 37a made of a silicon oxide film is formed by CVD under the following conditions, for example. TEOS and O ₂ are used as the CVD source gas, and the TEOS / O ₂ flow rate ratio is 500/1000 SCCM, the atmospheric pressure is 5 Pa, and the substrate temperature is 400 ° C.

Next, a resist film 38 is formed on the buffer layer 37a, and openings 40 are formed in the resist film 38 by a photolithography method in a predetermined pattern corresponding to the cathode holes. The inner diameter of this opening 40 is
It corresponds to the inner diameter of the cathode hole and is, for example, about 0.8 μm.

Next, the semiconductor substrate 30 having the resist film 38 formed thereon is placed in a plasma etching apparatus,
Etching is performed using the resist film 38 as a mask. The plasma etching apparatus is not particularly limited, but for example, a microwave electron cyclotron resonance plasma (ECR) etching apparatus, an induction coil type plasma (ICP) etching apparatus, a helicon wave utilizing plasma etching apparatus, a transformer coupled plasma (TCP) etching apparatus, etc. Can be illustrated.

First, for example, an ECR etching device is used.
The buffer layer 3 made of silicon oxide under the following conditions
7a is etched. As the etching gas,
CHF₃ And CH₂ F₂ CHF with a mixed gas of ₃ /
CH₂ F₂ The flow rate ratio of 50/10 SCCM. Atmospheric pressure
The force is 0.3 Pa. Also, the microwave power is
850W, radio frequency (RF) power is 200W
Therefore, the substrate temperature is −50 ° C.

Then, the tungsten silicide film 36 and
And the polysilicon film 34 is continuously etched. Etch
Clungs gas is Cl₂ And O₂ Using a mixed gas of
Cl ₂ / O₂ The flow rate ratio is 70/10 SCCM. atmosphere
The pressure is 0.4 Pa. Also microwave power
Is 850W and the radio frequency (RF) power is 40W
And the substrate temperature is 10 ° C.

Then, as shown in FIG.
For example, the insulating layer 32 is etched under the following conditions.
CHF is used as an etching gas₃ And CH₂ F₂ Mixed with
CHF using combined gas ₃ / CH₂ F₂ Flow rate of 50 /
It will be 10 SCCM. The atmospheric pressure is 0.3 Pa. Well
Also, the microwave power is 850 W, and the high frequency (R
F) The power is 300 W (800 kHz) and the substrate temperature
The degree is -50 ° C.

In the continuous etching of the multilayer film, the excessive overetching under the high energy condition causes
The resist film 38 recedes, the side wall of the opening 40 is also shaved, and the buffer layer 37a located thereunder is also partially etched to form a tapered shape. This is because the upper conductive layer 35 and the insulating layer 32 are etched by the same resist film 38, so that the time required for the resist film 38 to be exposed to plasma etching is longer than that in the conventional contact hole forming etching technique. It is thought that it has become. However, in this embodiment, since the buffer layer 37a is provided, the sidewall of the opening of the upper conductive layer 35 is not over-etched.

Next, as shown in FIG. 2C, the resist film 38 is removed by resist ashing, and subsequently, as shown in FIG. 2D, the buffer layer 37a is removed. The resist ashing is performed by using 500 SCCM of O ₂ under the conditions of an atmospheric pressure of 3.0 Pa, a substrate temperature of 200 ° C., and a radio frequency (RF) power of 300 W. The removal of the buffer layer 37a composed of a silicon oxide film is performed by wet etching with hydrofluoric acid in a ratio of water: hydrofluoric acid of about 5: 1. By this wet etching and washing with water, the buffer layer 37a made of a silicon oxide film is removed. At the same time, side etching also acts on the side wall of the cathode hole 44 of the insulating layer 32 made of silicon oxide or the like, and the inner diameter of the hole 44 becomes large as shown in FIG. Does not affect the coverage of. Rather, it contributes to prevention of short circuit between the upper electrode and the lower electrode.

As a result, at this point, the upper conductive layer 35 having no taper or shoulder drop is obtained. As a result, good vertical anisotropic etching is possible. Next, FIG.
As shown in (E), using an electron beam evaporation method or the like,
A peeling layer 46 is formed on the tungsten silicide film 36. The peeling layer 46 is composed of, for example, an aluminum metal layer. The layer thickness of the peeling layer 46 is not particularly limited, but is about 50 nm, for example. The substrate angle during electron beam evaporation is preferably about 20 degrees. The atmospheric pressure is 1.0 Pa, for example.

Next, as shown in FIG. 2F, a cathode forming layer 48 is deposited on the peeling layer 46 by using, for example, an electron beam evaporation method. Molybdenum (Mo) is preferably used for the cathode formation layer 48, but other refractory metals, other metals, compounds, or the like can also be used. The angle of the substrate during electron beam evaporation is
About 90 degrees is preferred. Cathode forming layer 48 is about 1.0 μ
By forming it with a layer thickness of m 2, the surface of the substrate 30 located at the bottom of the cathode hole 44 has a cathode 50 with an acute cone shape.
Are formed with a uniform shape and height. Each cathode 50
The shape, in particular the height, of each of the openings 4 of the cathode formation layer 48 is
It depends on the time until 8a is closed. In this embodiment, since there is no taper or shoulder drop on the side wall of the opening 40 of the tungsten silicide film 36, each opening 48 is formed.
The time until a is closed is also constant, and the shape, especially the height, of each cathode 50 can be made uniform.

Next, as shown in FIG. 2 (G), wet etching (about 30 seconds) is performed with hydrofluoric acid at a ratio of water: hydrofluoric acid of about 5: 1, and the peeling layer 46 made of aluminum or the like is used. Are removed by etching, and the cathode forming layer 48 located thereon is lifted off. In the cathode hole 44, the microcathode 20 having a uniform shape and height remains.

After that, a transparent substrate having a phosphor film formed thereon or a transparent substrate having a transparent conductive film formed thereon is laminated on the substrate 30 in a vacuum state to form an FED or an image pickup device. The present invention is not limited to the above-mentioned embodiments, but can be modified in various ways within the scope of the present invention.

[0051]

As described above, according to the present invention, a microcathode having a uniform shape and height can be formed without causing a defect due to an abnormal shape of a conductive layer formed of a tungsten silicide film or the like. Can be stably formed. A device using this microcathode is suitably used as an FED used for a flat display or the like, or an image pickup device.

[Brief description of drawings]

1A to 1G are cross-sectional views of a main part showing a method of manufacturing a microcathode according to a first embodiment of the present invention.

2 (A) to 2 (G) are cross-sectional views of a main part showing a method of manufacturing a microcathode according to a second embodiment of the present invention.

3 (A) to 3 (G) are cross-sectional views of relevant parts showing a method of manufacturing a microcathode according to a conventional example.

[Explanation of symbols]

 30 ... Semiconductor substrate 32 ... Insulating layer 34 ... Polysilicon film 35 ... Conductive layer 36 ... Tungsten silicide film 37, 37a ... Buffer layer 38 ... Resist film 40 ... Opening 44 ... Cathode hole 46 ... Peeling layer 48 ... Cathode forming layer 50 … Micro cathode

Claims (5)

[Claims] 1. A step of forming at least an insulating layer and then a conductive layer on a surface of a substrate, a step of forming a buffer layer on the conductive layer, and a resist film formed on the buffer layer. Steps, a step of patterning the resist film in a predetermined pattern in which a cathode hole is to be formed, and a patterning process using the resist film as a mask to form a cathode hole in the buffer layer, conductive layer and insulating layer. A method of manufacturing a field emission microcathode, comprising: a step, a step of removing the buffer layer, and a step of forming a microcathode in a cathode hole formed in the insulating layer. 2. The buffer layer has a layer thickness of 50 to 300 nm.
The method for manufacturing a field emission type microcathode according to claim 1. 3. The method for producing a microcathode according to claim 1, wherein the buffer layer is any one of a polysilicon layer, an amorphous silicon layer and an aluminum layer. 4. The method for producing a microcathode according to claim 1, wherein the buffer layer is any one of a silicon oxide layer, a silicon nitride layer and a silicon oxynitride layer. 5. The method for producing a microcathode according to claim 4, wherein when the buffer layer is removed by etching, the insulating layer corresponding to the inner wall of the cathode hole is receded at the same time.