Cold cathode field emission device and process for the production thereof, and cold cathode field emission display and process for the production thereof Number:7,118,927 from the United States Patent and Trademark Office (PTO) owispatent

Title: Cold cathode field emission device and process for the production thereof, and cold cathode field emission display and process for the production thereof

Abstract: A process for producing a cold cathode field emission device. A cathode electrode is formed on a front surface of a support member that transmits exposure light. An insulating layer is formed on an entire surface. A gate electrode is formed on the insulating layer. The support member is irradiated with exposure light from a back surface side of the support member through the hole as a mask for exposure. An electron-emitting-portion-forming-layer composed of a photosensitive material is formed at least inside the opening portion. The support member is irradiated with exposure light from a back surface side of the support member through the hole as a mask for exposure.

Patent Number: 7,118,927 Issued on 10/10/2006 to Toyota,   et al.

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Inventors:	Toyota; Motohiro (Kanagawa, JP), Saito; Ichiro (Kanagawa, JP), Shimamura; Toshiki (Kanagawa, JP), Muroyama; Masakazu (Kanagawa, JP)
Assignee:	Sony Corporation (Tokyo, JP)
Appl. No.:	11/091,448
Filed:	March 29, 2005

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Related U.S. Patent Documents

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	Application Number	Filing Date	Patent Number	Issue Date
	10395379	May., 2005	6900066

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Foreign Application Priority Data

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Mar 27, 2002 [JP]			P2002-088857

Current U.S. Class:	438/20 ; 438/257
Current International Class:	H01L 21/26 (20060101); H01L 21/66 (20060101)
Field of Search:	438/20,22,29,30,34,257,259

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References Cited [Referenced By]

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U.S. Patent Documents

	6297587		October 2001		Kikuchi et al.
	6465941		October 2002		Kubota et al.
	6580223		June 2003		Konishi et al.
	6771236		August 2004		Konishi et al.
	6900066		May 2005		Toyota et al.

Foreign Patent Documents

	03-246851		Nov., 1991		JP
	07-320629		Dec., 1995		JP
	07-320636		Dec., 1995		JP
	2000-215792		Aug., 2000		JP
	2000-285796		Oct., 2000		JP

Primary Examiner: Nhu; David
Attorney, Agent or Firm: Rader, Fishman & Grauer PLLC Kananen; Ronald P.

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Parent Case Text

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This is a continuation of application Ser. No. 10/395,379, filed Mar. 25, 2003, now U.S. Pat. No. 6,900,066, issued on May 31, 2005, the entire contents of which are hereby incorporated by reference.

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Claims

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What is claimed is:

1. A process for producing a cold cathode field emission device comprising the steps of; (A) forming a cathode electrode on a front surface of a support member that transmits exposure light, said cathode electrode having a hole in a bottom of which the support member is exposed, being composed of a material that does not transmit exposure light and extending in a first direction, (B) forming an insulating layer on an entire surface, said insulating layer being composed of a photosensitive material that transmits exposure light, (C) forming a gate electrode on the insulating layer, said gate electrode being composed of a photosensitive material and extending in a second direction different from the first direction, (D) irradiating the support member with exposure light from a back surface side of the support member through said hole using an exposure-light-shielding member as a mask for exposure, to expose the insulating layer and the gate electrode in portions above the hole to the exposure light, developing the insulating layer and the gate electrode to remove the insulating layer and the gate electrode in the portions above the hole, whereby an opening portion is formed through the insulating layer and the gate electrode above the hole and part of the cathode electrode is exposed in a bottom portion of the opening portion, said opening portion having a larger diameter than said hole, (E) forming an electron-emitting-portion-forming-layer composed of a photosensitive material at least inside the opening portion, and (F) irradiating the support member with exposure light from the back surface side of the support member through said hole using said exposure-light-shielding member as a mask for exposure, to expose the electron-emitting-portion-forming-layer above the hole to the exposure light, and developing the electron-emitting-portion-forming-layer to form an electron emitting portion constituted of the electron-emitting-portion-forming-layer on the cathode electrode and inside the hole.

2. A process for producing a cold cathode field emission device comprising the steps of; (A) forming a cathode electrode on a front surface of a support member that transmits exposure light, said cathode electrode having a hole in a bottom of which the support member is exposed, being composed of a material that does not transmit exposure light and extending in a first direction, (B) forming an insulating layer on an entire surface, said insulating layer being composed of a photosensitive material that transmits exposure light, (C) forming a gate electrode on the insulating layer, said gate electrode being composed of a photosensitive material and extending in a second direction different from the first direction, (D) irradiating the support member with exposure light from a back surface side of the support member through said hole using an exposure-light-shielding as a mask for exposure, to expose the insulating layer and the gate electrode in portions above the hole to the exposure light, developing the insulating layer and the gate electrode to remove the insulating layer and the gate electrode in the portions above the hole, whereby an opening portion is formed through the insulating layer and the gate electrode above the hole and part of the cathode electrode is exposed in a bottom portion of the opening portion, said opening portion having a larger diameter than said hole, (E) forming an electron-emitting-portion-forming-layer composed of a non-photosensitive material that transmits exposure light, at least inside the opening portion, (F) forming an etching mask layer composed of a resist material on said electron-emitting-portion-forming-layer, (G) irradiating the support member with exposure light from the back surface side of the support member through said hole using said exposure-light-shielding member as a mask for exposure, to expose the etching mask layer in a portion above the hole to the exposure light, and developing the etching mask layer to leave the etching mask layer on the electron-emitting-portion-forming-layer positioned in a bottom portion of the opening portion, and (H) etching the electron-emitting-portion-forming-layer with the etching mask layer, and then removing the etching mask layer, to form an electron emitting portion constituted of the electron-emitting-portion-forming-layer on the cathode electrode and inside the hole.

3. A process for producing a cold cathode field emission device comprising the steps of; (A) forming a cathode electrode on a front surface of a support member that transmits exposure light, said cathode electrode having a hole in a bottom of which the support member is exposed, being composed of a material that does not transmit exposure light and extending in a first direction, (B) forming an insulating layer composed of a non-photosensitive material that transmits exposure light on an entire surface, (C) forming a gate electrode on the insulating layer, said gate electrode being composed of a non-photosensitive material that transmits exposure light and extending in a second direction different from the first direction, (D) forming an etching mask layer composed of a resist material on the gate electrode and the insulating layer, (E) irradiating the support member with exposure light from a back surface side of the support member through said hole using an exposure-light-shielding member as a mask for exposure, to expose the etching mask layer to the exposure light, and then developing the etching mask layer to form a mask-layer-opening through the etching mask layer in a portion above the hole, (F) etching the gate electrode and the insulating layer below the mask-layer-opening with the etching mask layer, and then removing the etching mask layer, whereby an opening portion is formed through the insulating layer and the gate electrode above the hole and part of the cathode electrode is exposed in a bottom portion of the opening portion, said opening portion having a larger diameter than said hole, (G) forming an electron-emitting-portion-forming-layer composed of a photosensitive material at least inside the opening portion, and (H) irradiating the support member with exposure light from the back surface side of the support member through said hole using said exposure-light-shielding member as a mask for exposure, to expose the electron-emitting-portion-forming-layer above the hole to the exposure light, and developing the electron-emitting-portion-forming-layer to form an electron emitting portion constituted of the electron-emitting-portion-forming-layer on the cathode electrode and inside the hole.

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Description

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BACKGROUND OF THE INVENTION AND RELATED ART STATEMENT

The present invention relates to a cold cathode field emission device and a process for the production thereof, and a cold cathode field emission display and a process for the production thereof.

In the field of displays for use in television receivers and information terminals, flat type (flat panel type) displays that can comply with demands for a decrease in thickness, a decrease in weight, a larger screen size and a higher definition are being studied as substitutes for conventional mainstream cathode ray tubes (CRT). Such flat type displays include a liquid crystal display (LCD), an electroluminescence display (ELD), a plasma display (PDP) and a cold cathode field emission display (FED). Of these, the liquid crystal display is widely used as a display for an information terminal. When attempts are made to apply it to a stationary television receiver, however, it still has problems to solve for attaining a higher brightness and a larger screen size. In contrast, the cold cathode field emission display uses cold cathode field emission devices (to be sometimes referred to as "field emission device" hereinafter) capable of emitting electrons from a solid to a vacuum on the basis of a quantum tunnel effect without relying on thermal excitation. The cold cathode field emission display is therefore attracting great attention in view of a high brightness and a low power consumption.

FIGS. 32 and 33 show one example of the cold cathode field emission display (to be sometimes referred to as "display" hereinafter) having field emission devices. FIG. 32 is a schematic partial end view of a conventional display, and FIG. 33 is a schematic partial exploded perspective view of a cathode panel CP and an anode panel AP.

Each field emission device shown in FIG. 32 is a field emission device that is a so-called Spindt-type field emission device having a conical electron emitting portion. The above field emission device comprises a cathode electrode 111 formed on a support member 110, an insulating layer 112 formed on the support member 110 and the cathode electrode 111, a gate electrode 113 formed on the insulating layer 112, an opening portion 114 made through the gate electrode 113 and the insulating layer 112 (first opening portion 114A made through the gate electrode 113 and a second opening portion 114B made through the insulating layer 112), and a conical electron emitting portion 115A formed on the cathode electrode 111 positioned in a bottom portion of the second opening portion 114B. Generally, the cathode electrode 111 and the gate electrode 113 are formed in the form of a stripe each and in directions in which projection images of these electrodes cross each other at right angles, and a plurality of field emission devices are generally formed in a region where the projection images of these electrodes overlap. Such a region corresponds to a region occupying one pixel and will be referred to as "overlap region" or "electron emitting region". Further, such electron emitting regions are arranged in the effective field (field that works as an actual display portion) of the cathode panel CP such that they are arranged in the form of two-dimensional matrix.

The anode panel AP comprises a substrate 30, a phosphor layer 31 (31R, 31B, 31G) that is formed on the substrate 30 and has a predetermined pattern, and an anode electrode 33 formed thereon. One pixel is constituted of a group of the field emission devices formed in the overlap region of the cathode electrode 111 and the gate electrode 113 on the cathode panel side, and the phosphor layer 31 being on the anode panel side and facing the group of the field emission devices. In the effective field, such pixels are arranged, for example, on the order of several hundred thousand to several million. A black matrix 32 is formed on the substrate 30 that appears between such phosphor layers 31.

The anode panel AP and the cathode panel CP are arranged such that the electron emitting region and the phosphor layer 31 face each other, and bonded to each other in their circumferential portions through a frame 34, whereby the display can be produced. An ineffective field surrounding the effective field and having a peripheral circuit for selecting pixels (ineffective field of the cathode panel CP in the shown example) is provided with a through-hole 36 for vacuuming, and a tip tube 37 that is sealed after vacuuming is connected to the through-hole 36. That is, a space surrounded by the anode panel AP, the cathode panel CP and the frame 34 is vacuumed and constitutes a vacuum space.

A relatively negative voltage is applied to the cathode electrode 111 from a cathode-electrode control circuit 40, a relatively positive voltage is applied to the gate electrode 113 from a gate-electrode control circuit 41, and a positive voltage higher than the voltage applied to the gate electrode 113 is applied to the anode electrode 33 from an anode-electrode control circuit 42. When the above display is allowed to perform displaying, for example, a scanning signal is inputted to the cathode electrode 111 from the cathode-electrode control circuit 40, and a video signal is inputted to the gate electrode 113 from the gate-electrode control circuit 41. An electric field generated by the voltages applied to the cathode electrode 111 and the gate electrode 113 causes the electron emitting portion 115A to emit electrons on the basis of a quantum tunnel effect, and the electrons are attracted toward the anode electrode 33 to collide with the phosphor layer 31. As a result, the phosphor layer 31 is exited to emit light, and a desired image can be obtained. That is, the operation of the display is controlled, in principle, on the basis of the voltage applied to the gate electrode 113 and the voltage applied to the electron emitting portion 115A through the cathode electrode 111.

The method for producing a Spindt-type field emission device will be explained hereinafter with reference to FIGS. 34A and 34B and FIGS. 35A and 35B which are schematic partial end views of the support member 110, etc., constituting the cathode panel.

Basically, the above Spindt-type field emission device can be obtained by a method of forming each electron emitting portion 115A by vertical vapor deposition of a metal material. That is, deposition particles enter perpendicularly to the first opening portion 114A made through the gate electrode 113. However, the amount of deposition particles that reach a bottom portion of the second opening portion 114B is gradually decreased by the shield effect of an overhanging deposit that is formed in the vicinity of the opening edge of the first opening portion 114A, and the-electron emitting portion 115A that is a conical deposit is formed in a self-aligned manner. The method for producing the Spindt-type field emission device will be explained with regard to a method of forming a peel layer 116 on the gate electrode 113 and the insulating layer 112 beforehand for making it easy to remove an unnecessary overhanging deposit. FIGS. 34A and 34B and FIGS. 35A and 35B show one electron emitting portion.

[Step-10]

First, an electrically conductive material layer for a cathode electrode, for example, made of polysilicon, is formed on the support member 110 made, for example, of a glass substrate by a plasma CVD method, and then the electrically conductive material layer for a cathode electrode is patterned by lithography and a dry etching technique, to form the stripe-shaped cathode electrode 111. Then, the insulating layer 112 made of SiO.sub.2 is formed on the entire surface by a CVD method.

[Step-20]

Then, an electrically conductive material layer (for example, TiN layer) for a gate electrode is formed on the insulating layer 112 by a sputtering method, and then the electrically conductive material layer for a gate electrode is patterned by lithography and a dry etching technique, whereby the stripe-shaped gate electrode 113 can be obtained. The stripe-shaped cathode electrode 111 extends leftward and rightward on the paper surface of the drawing, and the stripe-shaped gate electrode 113 extends perpendicularly to the paper surface of the drawing.

[Step-30]

Then, a resist layer is formed again, and the first opening portion 114A is formed through the gate electrode 113 by etching, and further, the second opening portion 114B is formed through the insulating layer 112 by etching. The cathode electrode 111 is exposed in the bottom portion of the second opening portion 114B, and then, the resist layer is removed. In the above manner, a structure shown in FIG. 34A can be obtained.

[Step-40]

Then, while the support member 110 is turned, nickel (Ni) is obliquely deposited on the insulating layer 112 and the gate electrode 113, to form the peel layer 116 (see FIG. 34B). In this case, the incidence angle of deposition particles with respect to the normal of the support member 110 is determined to be sufficiently large (for example, incidence angle of 65 to 85 degrees), whereby the peel layer 116 can be formed on the gate electrode 113 and the insulating layer 112 almost without depositing nickel on the bottom portion of the second opening portion 114B. The peel layer 116 extends from the opening edge of the first opening portion 114A like the form of eaves, and due to the peel layer 116, the diameter of the first opening portion 114A is substantially decreased.

[Step-50]

Then, an electrically conductive material such as molybdenum (Mo) is vertically (incidence angle of 3 to 10 degrees) deposited on the entire surface. In this case, with the growth of an electrically conductive material layer 117 having an overhanging form on the peel layer 116 as shown in FIG. 35A, the substantial diameter of the first opening portion 114A is decreased, so that deposition particles that contributes to the formation of a deposit on the bottom portion of the second opening portion 114B come to be gradually limited to deposition particles that pass the center of the first opening portion 114A. As a result, a conical deposit is formed on the bottom portion of the second opening portion 114B, and the conical deposit constitutes the electron emitting portion 115A.

[Step-60]

Then, the peel layer 116 is removed from the surface of the gate electrode 113 and the insulating layer 112 by a lift-off method, to selectively remove the electrically conductive material layer 117 above the gate electrode 113 and the insulating layer 112. In this manner, a cathode panel CP having a plurality of Spindt-type field emission devices can be obtained.

For obtaining a large amount of current of emitted electrons at a low driving voltage in the above display, it is effective to acutely sharpen the top end portion of the electron emitting portion. From this viewpoint, the electron emitting portion 115A of the above Spindt-type field emission device can be said to have an excellent performance. The above process for producing the Spindt-type field emission device is an excellent process capable of forming a conical deposit, as the electron emitting portion 115A, in the opening portions 114A and 114B in a self-aligned manner. However, it requires a high processing technique to form such conical electron emitting portions 115A, and with an increase in size of the display and with an increase in area of the effective field, it is getting difficult to uniformly form such electron emitting portions 115A that are sometimes several tens of millions in number in the entire region of the effective field. Further, many apparatuses for producing semiconductor devices are used, and when the display is increased in size, it is required to increase the size of the apparatuses for producing semiconductor devices, which causes the display production cost to increase.

There has been therefore proposed a so-called flat-type field emission device that does not employ any conical electron emitting portion but employs a flat electron emitting portion exposed on the bottom portion of the opening portion. In the flat-type field emission device, each electron emitting portion is formed on the cathode electrode positioned in the bottom portion of the opening portion, and is constituted of a material having a lower work function than a material constituting the cathode electrode so that the electron emitting portion can accomplish a larger current of emitted electrons even if it has a flat form. In recent years, various carbon materials including carbon nanotubes have been proposed as the above material.

In the production of the above flat-type field emission device, for example, a negative-type photosensitive paste layer 118 containing carbon nanotubes is formed on the entire surface including the inside of the opening portion 114 after a structure shown in FIG. 34A is obtained (see FIG. 36A). Then, the photosensitive paste layer 118 is exposed to light (see FIG. 36B), followed by development and removal of the photosensitive paste layer 118 in an unnecessary region. Then, the remaining photosensitive paste layer 118 is fired, whereby the electron emitting portion 115 can be obtained (see FIG. 36C). A reference numeral 119 shows a mask for exposure.

When the photosensitive paste layer 118 is exposed to light, the mask for exposure 119 is positioned in regard to a reference marker (not shown) provided beforehand, for avoiding a positional deviation between the mask for exposure 119 and the opening portion 114.

However, the support member 110 suffers deformation, for example, due to the thermal history of the support member 110 or due to stresses, etc., of various layers (cathode electrode 111, insulating layer 112, gate electrode 113, etc.) formed on the support member 110. As a result, a positional deviation frequently takes place between the mask for exposure 119 and the opening portion 114 when the photosensitive paste layer 118 is exposed to light. When the above phenomenon takes place, the distance from the opening edge of the first opening portion 114A made through the gate electrode 113 to the electron emitting portion 115 positioned in the bottom portion of the second opening portion 114B varies, and as a result, the amount of emitted electrons varies among such electron emitting portions 115, which causes display non-uniformity to take place. In the worst case, the photosensitive paste layer 118 remains on the side wall of the opening portion 114 and forms a short circuit between the gate electrode 113 and the cathode electrode 111.

OBJECT AND SUMMARY OF THE INVENTION

It is therefore an object of the present invention to provide a process for producing a cold cathode field emission device, which process makes it possible to form an electron emitting portion in a bottom portion of an opening portion made through a gate electrode and an insulating layer in a self-aligned manner in regard to the opening portion, a process for producing a cold cathode field emission display to which the above process is applied, and a cold cathode field emission device and cold cathode field emission display obtained by the above processes.

A process for producing a cold cathode field emission device according to a first-A aspect of the present invention for achieving the above object comprises the steps of;

(A) forming a cathode electrode on the front surface of a support member that transmits exposure light, said cathode electrode having a hole in a bottom of which the support member is exposed, being composed of a material that does not transmit exposure light and extending in a first direction,

(B) forming an insulating layer on the entire surface, said insulating layer being composed of a photosensitive material that transmits exposure light,

(C) forming a gate electrode on the insulating layer, said gate electrode being composed of a photosensitive material and extending in a second direction different from the first direction,

(D) irradiating the support member with exposure light from the back surface side of the support member through said hole as a mask for exposure, to expose the insulating layer and the gate electrode in portions above the hole to the exposure light, developing the insulating layer and the gate electrode to remove the insulating layer and the gate electrode in the portions above the hole, whereby an opening portion is formed through the insulating layer and the gate electrode above the hole and part of the cathode electrode is exposed in a bottom portion of the opening portion, said opening portion having a larger diameter than said hole,

(E) forming an electron-emitting-portion-forming-layer composed of a photosensitive material at least inside the opening portion, and

(F) irradiating the support member with exposure light from the back surface side of the support member through said hole as a mask for exposure, to expose the electron-emitting-portion-forming-layer above the hole to the exposure light, and developing the electron-emitting-portion-forming-layer to form an electron emitting portion constituted of the electron-emitting-portion-forming-layer on the cathode electrode and inside the hole.

A process for producing a cold cathode field emission display, provided by the present invention, for achieving the above object comprises arranging a substrate having an anode electrode and a phosphor layer and a support member having a cold cathode field emission device such that the phosphor layer and the cold cathode field emission device face each other, and bonding the substrate and the support member in their circumferential portions.

A process for producing a cold cathode field emission display according to a first-A aspect of the present invention comprises producing a cold cathode field emission device on the basis of steps (A) to (F) of the process for producing a cold cathode field emission device according to the above first-A aspect of the present invention.

In explanations to be given below, the steps will be sometimes abbreviated as follows.

The step of "forming a cathode electrode on the front surface (first surface) of a support member that transmits exposure light, said cathode electrode having a hole in a bottom of which the support member is exposed, being composed of a material that does not transmit exposure light and extending in a first direction" will be sometimes abbreviated as the step of "forming a cathode electrode".

The step of "forming an insulating layer on the entire surface, said insulating layer being composed of a photosensitive material that transmits exposure light" will be sometimes abbreviated as the step of "forming an insulating layer composed of a photosensitive material that transmits exposure light".

The step of "forming a gate electrode on the insulating layer, said gate electrode being composed of a photosensitive material and extending in a second direction different from the first direction" will be sometimes abbreviated as the step of "forming a gate electrode composed of a photosensitive material".

The step of "irradiating the support member with exposure light from the back surface (second surface) side of the support member through said hole as a mask for exposure, to expose the insulating layer and the gate electrode in portions above the hole to the exposure light, developing the insulating layer and the gate electrode to remove the insulating layer and the gate electrode in the portions above the hole, whereby an opening portion is formed through the insulating layer and the gate electrode above the hole and part of the cathode electrode is exposed in a bottom portion of the opening portion, said opening portion having a larger diameter than said hole" will be sometimes abbreviated as the step of "forming an opening portion by exposure from the back surface side and exposing the cathode electrode".

The step of "forming an electron-emitting-portion-forming-layer composed of a photosensitive material at least inside the opening portion" will be sometimes abbreviated as the step of "forming an electron-emitting-portion-forming-layer composed of a photosensitive material".

The step of "irradiating the support member with exposure light from the back surface (second surface) side of the support member through said hole as a mask for exposure, to expose the electron-emitting-portion-forming-layer above the hole to the exposure light, and developing the electron-emitting-portion-forming-layer to form an electron emitting portion constituted of the electron-emitting-portion-forming-layer on the cathode electrode and inside the hole" will be sometimes abbreviated as the step of "forming an electron emitting portion on the cathode electrode by exposure and development".

In the process for producing a cold cathode field emission device or a cold cathode field emission display according to the first-A aspect of the present invention, in a process for producing a cold cathode field emission device or a cold cathode field emission display according to any one of a first-B aspect to a first-D aspect to be described later, and in a process for producing a cold cathode field emission device or a cold cathode field emission display according to any one of a third-A aspect to a third-D aspect to be described later, the opening portion is formed through the gate electrode and the insulating layer by a back-surface-exposure method in which the back surface (second surface) of the support member is exposed to light.

In a process for producing a cold cathode field emission device or a cold cathode field emission display according to a second-A aspect, a second-B aspect, a fourth-A aspect or a fourth-B aspect to be described later, an opening portion is formed through a gate electrode and an insulating layer by a front-surface-exposure method in which the front surface (first surface) of a support member is exposed to light.

A process for producing a cold cathode field emission device or a cold cathode field emission display according to any one of a third-A aspect to a third-D aspect, a fourth-A aspect and a fourth-B aspect differs from the process for producing a cold cathode field emission device or a cold cathode field emission display according to any one of the first-A aspect to a first-D aspect, a second-A aspect and a second-B aspect in that a light-transmittable layer is formed and that an electron emitting portion is formed on the light-transmittable layer.

A process for producing a cold cathode field emission device according to a first-B aspect of the present invention for achieving the above object comprises the steps of;

(A) "forming a cathode electrode",

(B) "forming an insulating layer composed of a photosensitive material that transmits exposure light",

(C) "forming a gate electrode composed of a photosensitive material",

(D) "forming an opening portion by exposure from the back surface side and exposing the cathode electrode",

(E) forming an electron-emitting-portion-forming-layer composed of a non-photosensitive material that transmits exposure light, at least inside the opening portion,

(F) forming an etching mask layer composed of a resist material on the entire surface,

(G) irradiating the support member with exposure light from the back surface side of the support member through said hole as a mask for exposure, to expose the etching mask layer in a portion above the hole to the exposure light, and developing the etching mask layer to leave the etching mask layer on the electron-emitting-portion-forming-layer positioned in a bottom portion of the opening portion, and

(H) etching the electron-emitting-portion-forming-layer with the etching mask layer, and then removing the etching mask layer, to form an electron emitting portion constituted of the electron-emitting-portion-forming-layer on the cathode electrode and inside the hole.

A process for producing a cold cathode field emission display according to a first-B aspect of the present invention comprises producing a cold cathode field emission device on the basis of steps (A) to (H) of the process for producing a cold cathode field emission device according to the first-B aspect of the present invention.

The step of "forming an electron-emitting-portion-forming-layer composed of a non-photosensitive material that transmits exposure light, at least inside the opening portion" will be sometimes abbreviated as the step of "forming an electron-emitting-portion-forming-layer composed of a non-photosensitive material".

Further, the step of "forming an etching mask layer composed of a resist material on the entire surface" will be sometimes abbreviated as the step of "forming an etching mask layer".

Further, the step of "irradiating the support member with exposure light from the back surface (second surface) side of the support member through said hole as a mask for exposure, to expose the etching mask layer in a portion above the hole to the exposure light, and developing the etching mask layer to leave the etching mask layer on the electron-emitting-portion-forming-layer positioned in a bottom portion of the opening portion" will be sometimes abbreviated as the step of "exposing and developing the etching mask layer".

The step of "etching the electron-emitting-portion-forming-layer with the etching mask layer, and then removing the etching mask layer, to form an electron emitting portion constituted of the electron-emitting-portion-forming-layer on the cathode electrode and inside the hole" will be sometimes abbreviated as the step of "forming an electron emitting portion on the cathode electrode on the basis of etching".

A process for producing a cold cathode field emission device according to a first-C aspect of the present invention for achieving the above object comprises the steps of;

(A) "forming a cathode electrode",

(B) forming an insulating layer composed of a non-photosensitive material that transmits exposure light on the entire surface,

(C) forming a gate electrode on the insulating layer, said gate electrode being composed of a non-photosensitive material that transmits exposure light and extending in a second direction different from the first direction,

(D) forming an etching mask layer composed of a resist material on the gate electrode and the insulating layer,

(E) irradiating the support member with exposure light from the back surface side of the support member through said hole as a mask for exposure, to expose the etching mask layer to the exposure light, and then developing the etching mask layer to form a mask-layer-opening through the etching mask layer in a portion above the hole,

(F) etching the gate electrode and the insulating layer below the mask-layer-opening with the etching mask layer, and then removing the etching mask layer, whereby an opening portion is formed through the insulating layer and the gate electrode above the hole and part of the cathode electrode is exposed in a bottom portion of the opening portion, said opening portion having a larger diameter than said hole,

(G) "forming an electron-emitting-portion-forming-layer composed of a photosensitive material", and

(H) "forming an electron emitting portion on the cathode electrode by exposure and development".

A process for producing a cold cathode field emission display according to a first-C aspect of the present invention comprises producing a cold cathode field emission device on the basis of steps (A) to (H) of the process for producing a cold cathode field emission device according to the first-C aspect of the present invention.

The step of "forming an insulating layer composed of a non-photosensitive material that transmits exposure light on the entire surface" will be sometimes abbreviated as the step of "forming an insulating layer composed of a non-photosensitive material that transmits exposure light".

The step of "forming a gate electrode on the insulating layer, said gate electrode being composed of a non-photosensitive material that transmits exposure light and extending in a second direction different from the first direction" will be sometimes abbreviated as the step of "forming a gate electrode composed of a non-photosensitive material".

Further, the step of "forming an etching mask layer composed of a resist material on the gate electrode and the insulating layer" will be sometimes abbreviated as the step of "forming an etching mask layer on the gate electrode and the insulating layer".

Further, the step of "irradiating the support member with exposure light from the back surface (second surface) side of the support member through said hole as a mask for exposure, to expose the etching mask layer to the exposure light, and then developing the etching mask layer to form a mask-layer-opening through the etching mask layer in a portion above the hole" will be abbreviated as the step of "forming a mask-layer-opening through the etching mask layer".

A process for producing a cold cathode field emission device according to a first-D aspect of the present invention for achieving the above object comprises the steps of;

(A) "forming a cathode electrode",

(B) "forming an insulating layer composed of a non-photosensitive material that transmits exposure light",

(C) "forming a gate electrode composed of a non-photosensitive material",

(D) forming a first etching mask layer composed of a resist material on the gate electrode and the insulating layer,

(E) irradiating the support member with exposure light from the back surface side of the support member through said hole as a mask for exposure to expose the first etching mask layer to the exposure light, and then developing the first etching mask layer to form a mask-layer-opening through the first etching mask layer in a portion above the hole,

(F) etching the gate electrode and the insulating layer below the mask-layer-opening with the first etching mask layer, and then removing the first etching mask layer, whereby an opening portion is formed through the insulating layer and the gate electrode above the hole and part of the cathode electrode is exposed in a bottom portion of the opening portion, said opening portion having a larger diameter than said hole,

(G) "forming an electron-emitting-portion-forming-layer composed of a non-photosensitive material",

(H) forming a second etching mask layer composed of a resist material on the entire surface,

(I) irradiating the support member with exposure light from the back surface side of the support member through said hole as a mask for exposure, to expose the second etching mask layer to the exposure light in a portion above the hole, and then developing the second etching mask layer, thereby to leave the second etching mask layer on the electron-emitting-portion-forming-layer positioned in a bottom portion of the opening portion, and

(J) etching the electron-emitting-portion-forming-layer with the second etching mask layer, and then removing the second etching mask layer, to form an electron emitting portion constituted of the electron-emitting-portion-forming-layer on the cathode electrode and inside the hole.

A process for producing a cold cathode field emission display according to a first-D aspect of the present invention comprises producing a cold cathode field emission device on the basis of steps (A) to (J) of the above process for producing a cold cathode field emission device according to the first-D aspect of the present invention.

The step of "forming a first etching mask layer composed of a resist material on the gate electrode and the insulating layer" will be sometimes abbreviated as the step of "forming a first etching mask layer on the gate electrode and the insulating layer".

Further, the step of "irradiating the support member with exposure light from the back surface (second surface) side of the support member through said hole as a mask for exposure to expose the first etching mask layer to the exposure light, and then developing the first etching mask layer to form a mask-layer-opening through the first etching mask layer in a portion above the hole" will be sometimes abbreviated as the step of "forming a mask-layer-opening through the first etching mask layer".

Further, the step of "forming a second etching mask layer composed of a resist material on the entire surface" will be sometimes abbreviated as the step of "forming a second etching mask layer".

Further, the step of "irradiating the support member with exposure light from the back surface (second surface) side of the support member through said hole as a mask for exposure, to expose the second etching mask layer to the exposure light in a portion above the hole, and then developing the second etching mask layer, thereby to leave the second etching mask layer on the electron-emitting-portion-forming-layer positioned in a bottom portion of the opening portion" will be sometimes abbreviated as the step of "exposing and developing the second etching mask layer".

A process for producing a cold cathode field emission device according to a second-A aspect of the present invention for achieving the above object comprises the steps of;

(A) "forming a cathode electrode",

(B) forming an insulating layer composed of a photosensitive material on the entire surface,

(C) forming a gate electrode on the insulating layer, said gate electrode being composed of a photosensitive material that transmits exposure light and extending in a second direction different from the first direction,

(D) irradiating the support member with exposure light from the front surface side of the support member to expose the gate electrode and the insulating layer to the exposure light, and then developing the gate electrode and the insulating layer, whereby an opening portion is formed through the gate electrode and the insulating layer above the hole and part of the cathode electrode is exposed in a bottom portion of the opening portion, said opening portion having a larger diameter than said hole,

(E) "forming an electron-emitting-portion-forming-layer composed of a photosensitive material", and

(F) "forming an electron emitting portion on the cathode electrode by exposure and development".

A process for producing a cold cathode field emission display according to a second-A aspect of the present invention comprises producing a cold cathode field emission device on the basis of steps (A) to (F) of the above process for producing a cold cathode field emission device according to the second-A aspect of the present invention.

The step of "forming an insulating layer composed of a photosensitive material on the entire surface" will be sometimes abbreviated as the step of "forming an insulating layer composed of a photosensitive material".

The step of "forming a gate electrode on the insulating layer, said gate electrode being composed of a photosensitive material that transmits exposure light and extending in a second direction different from the first direction" will be sometimes abbreviated as the step of "forming a gate electrode composed of a photosensitive material that transmits exposure light".

Further, the step of "irradiating the support member with exposure light from the front surface (first surface) side of the support member to expose the gate electrode and the insulating layer to the exposure light, and then developing the gate electrode and the insulating layer, whereby an opening portion is formed through the gate electrode and the insulating layer above the hole and part of the cathode electrode is exposed in a bottom portion of the opening portion, said opening portion having a larger diameter than said hole" will be abbreviated as the step of "forming an opening portion by exposure from the front surface side".

A process for producing a cold cathode field emission device according to a second-B aspect of the present invention for achieving the above object comprises the steps of;

(A) "forming a cathode electrode",

(B) "forming an insulating layer composed of a photosensitive material",

(C) "forming a gate electrode composed of a photosensitive material that transmits exposure light",

(D) "forming an opening portion by exposure from the front surface side",

(E) "forming an electron-emitting-portion-forming-layer composed of a non-photosensitive material",

(F) "forming an etching mask layer",

(G) "exposing and developing the etching mask layer", and

(H) "forming an electron emitting portion on the cathode electrode on the basis of etching".

A process for producing a cold cathode field emission display according to a second-B aspect of the present invention comprises producing a cold cathode field emission device on the basis of steps (A) to (H) of the above process for producing a cold cathode field emission device according to the second-B aspect of the present invention.

A process for producing a cold cathode field emission device according to a third-A aspect of the present invention for achieving the above object comprises the steps of;

(A) "forming a cathode electrode",

(B) forming a light-transmittable layer composed of an electrically conductive material or a resistance material that transmits exposure light, at least inside the hole,

(C) "forming an insulating layer composed of a photosensitive material that transmits exposure light",

(D) "forming a gate electrode composed of a photosensitive material",

(E) irradiating the support member from the back surface side of the support member through said hole as a mask for exposure to expose the insulating layer and the gate electrode to the exposure light in portions above the hole, then, developing the insulating layer and the gate electrode to remove the insulating layer and the gate electrode in portions above the hole, whereby an opening portion is formed through the insulating layer and the gate electrode above the hole and the light-transmittable layer is exposed in a bottom portion of the opening portion,

(F) "forming an electron-emitting-portion-forming-layer composed of a photosensitive material", and

(G) irradiating the support member from the back surface side of the support member through said hole as a mask for exposure to expose the electron-emitting-portion-forming-layer to the exposure light in a portion above the hole, and then developing the electron-emitting-portion-forming-layer to form an electron emitting portion constituted of the electron-emitting-portion-forming-layer on the light-transmittable layer.

A process for producing a cold cathode field emission display according to a third-A aspect of the present invention comprises producing a cold cathode field emission device on the basis of steps (A) to (G) of the above process for producing a cold cathode field emission device according to the third-A aspect of the present invention.

The step of "forming a light-transmittable layer composed of an electrically conductive material or a resistance material that transmits exposure light, at least inside the hole" will be sometimes abbreviated as the step of "forming a light-transmittable layer".

The step of "irradiating the support member from the back surface (second surface) side of the support member through said hole as a mask for exposure to expose the insulating layer and the gate electrode to the exposure light in portions above the hole, then, developing the insulating layer and the gate electrode to remove the insulating layer and the gate electrode in portions above the hole, whereby an opening portion is formed through the insulating layer and the gate electrode above the hole and the light-transmittable layer is exposed in a bottom portion of the opening portion" will be sometimes abbreviated as the step of "forming an opening portion by exposure from the back surface side and exposing the light-transmittable layer".

Further, the step of "irradiating the support member from the back surface (second surface) side of the support member through said hole as a mask for exposure to expose the electron-emitting-portion-forming-layer to the exposure light in a portion above the hole, and then developing the electron-emitting-portion-forming-layer to form an electron emitting portion constituted of the electron-emitting-portion-forming-layer on the light-transmittable layer" will be sometimes abbreviated as the step of "forming an electron emitting portion on the light-transmittable layer by exposure and development".

A process for producing a cold cathode field emission device according to a third-B aspect of the present invention for achieving the above object comprises the steps of;

(A) "forming a cathode electrode",

(B) "forming a light-transmittable layer",

(C) "forming an insulating layer composed of a photosensitive material that transmits exposure light",

(D) "forming a gate electrode composed of a photosensitive material",

(E) "forming an opening portion by exposure from the back surface side and exposing the light-transmittable layer",

(F) "forming an electron-emitting-portion-forming-layer composed of a non-photosensitive material",

(G) "forming an etching mask layer",

(H) "exposing and developing the etching mask layer", and

(I) etching the electron-emitting-portion-forming-layer with the etching mask layer, and then removing the etching mask layer, to form an electron emitting portion constituted of the electron-emitting-portion-forming-layer on the light-transmittable layer.

A process for producing a cold cathode field emission display according to a third-B aspect of the present invention comprises producing a cold cathode field emission device on the basis of steps (A) to (I) of the above process for producing a cold cathode field emission device according to the third-B aspect of the present invention.

The step of "etching the electron-emitting-portion-forming-layer with the etching mask layer, and then removing the etching mask layer, to form an electron emitting portion constituted of the electron-emitting-portion-forming-layer on the light-transmittable layer" will be sometimes abbreviated as the step of "forming an electron emitting portion on the light-transmittable layer on the basis of etching".

A process for producing a cold cathode field emission device according to a third-C aspect of the present invention for achieving the above object comprises the steps of;

(A) "forming a cathode electrode",

(B) "forming a light-transmittable layer",

(C) "forming an insulating layer composed of a non-photosensitive material that transmits exposure light",

(D) "forming a gate electrode composed of a non-photosensitive material",

(E) "forming an etching mask layer on the gate electrode and the insulating layer",

(F) "forming a mask-layer-opening through the etching mask layer",

(G) etching the gate electrode and the insulating layer below the mask-layer-opening with the etching mask layer, and then removing the etching mask layer, whereby an opening portion is formed through the insulating layer and the gate electrode above the hole and the light-transmittable layer is exposed in a bottom portion of the opening portion,

(H) "forming an electron-emitting-portion-forming-layer composed of a photosensitive material", and

(I) "forming an electron emitting portion on the light-transmittable layer by exposure and development".

A process for producing a cold cathode field emission display according to a third-C aspect of the present invention comprises producing a cold cathode field emission device on the basis of steps (A) to (I) of the above process for producing a cold cathode field emission device according to the third-C aspect of the present invention.

A process for producing a cold cathode field emission device according to a third-D aspect of the present invention for achieving the above object comprises the steps of;

(A) "forming a cathode electrode",

(B) "forming a light-transmittable layer",

(C) "forming an insulating layer composed of a non-photosensitive material that transmits exposure light",

(D) "forming a gate electrode composed of a non-photosensitive material",

(E) "forming a first etching mask layer on the gate electrode and the insulating layer",

(F) "forming a mask-layer-opening through the first etching mask layer",

(G) etching the gate electrode and the insulating layer in portions below the mask-layer-opening with the first etching mask layer, and then removing the first etching mask layer, whereby an opening portion is formed through the insulating layer and the gate electrode above the hole and the light-transmittable layer is exposed in a bottom portion of the opening portion,

(H) "forming an electron-emitting-portion-forming-layer composed of a non-photosensitive material",

(I) "forming a second etching mask layer",

(J) "exposing and developing the second etching mask layer", and

(K) etching the electron-emitting-portion-forming-layer with the second etching mask layer and then removing the second etching mask layer, to form an electron emitting portion constituted of the electron-emitting-portion-forming-layer on the light-transmittable layer.

A process for producing a cold cathode field emission display according to a third-D aspect of the present invention comprises producing a cold cathode field emission device on the basis of steps (A) to (K) of the above process for producing a cold cathode field emission device according to the third-D aspect of the present invention.

A process for producing a cold cathode field emission device according to a fourth-A aspect of the present invention for achieving the above object comprises the steps of;

(A) "forming a cathode electrode",

(B) "forming a light-transmittable layer",

(C) "forming an insulating layer composed of a photosensitive material",

(D) "forming a gate electrode composed of a photosensitive material that transmits exposure light",

(E) irradiating the support member with exposure light from the front surface side of the support member to expose the gate electrode and the insulating layer to the exposure light, and then developing the gate electrode and the insulating layer, whereby an opening portion is formed through the gate electrode and the insulating layer above the hole and the light-transmittable layer is exposed in a bottom portion of the opening portion,

(F) "forming an electron-emitting-portion-forming-layer composed of a photosensitive material", and

(G) "forming an electron emitting portion on the light-transmittable layer by exposure and development".

A process for producing a cold cathode field emission display according to a fourth-A aspect of the present invention comprises producing a cold cathode field emission device on the basis of steps (A) to (G) of the above process for producing a cold cathode field emission device according to the fourth-A aspect of the present invention.

The step of "irradiating the support member with exposure light from the front surface (first surface) side of the support member to expose the gate electrode and the insulating layer to the exposure light, and then developing the gate electrode and the insulating layer, whereby an opening portion is formed through the gate electrode and the insulating layer above the hole and the light-transmittable layer is exposed in a bottom portion of the opening portion" will be sometimes abbreviated as the step of "exposing the light-transmittable layer in a bottom portion of the opening portion".

A process for producing a cold cathode field emission device according to a fourth-B aspect of the present invention for achieving the above object comprises the steps of;

(A) "forming a cathode electrode",

(B) "forming a light-transmittable layer",

(C) "forming an insulating layer composed of a photosensitive material",

(D) "forming a gate electrode composed of a photosensitive material that transmits exposure light",

(E) "exposing the light-transmittable layer in a bottom portion of the opening portion",

(F) "forming an electron-emitting-portion-forming-layer composed of a non-photosensitive material",

(G) "forming an etching mask layer",

(H) "exposing and developing the etching mask layer", and

(I) "forming an electron emitting portion on the light-transmittable layer on the basis of etching".

A process for producing a cold cathode field emission display according to a fourth-B aspect of the present invention comprises producing a cold cathode field emission device on the basis of steps (A) to (I) of the above process for producing a cold cathode field emission device according to the fourth-B aspect of the present invention.

A cold cathode field emission device according to a first aspect of the present invention for achieving the above object comprises;

(a) a cathode electrode formed on a support member and extending in a first direction,

(b) an insulating layer formed on the support member and the cathode electrode,

(c) a gate electrode formed on the insulating layer and extending in a second direction different from the first direction,

(d) an opening portion formed through the gate electrode and the insulating layer, and

(e) an electron emitting portion,

wherein electrons are emitted from the electron emitting portion exposed in a bottom portion of the opening portion,

and wherein a hole reaching the support member is provided in that portion of the cathode electrode which portion is positioned in the bottom portion of the opening portion, and

the electron emitting portion is formed on that portion of the cathode electrode, which portion is positioned in the bottom portion of the opening portion, and inside the hole.

A cold cathode field emission device according to a second aspect of the present invention for achieving the above object comprises;

(a) a cathode electrode formed on a support member and extending in a first direction,

(b) an insulating layer formed on the support member and the cathode electrode,

(c) a gate electrode formed on the insulating layer and extending in a second direction different from the first direction,

(d) an opening portion formed through the gate electrode and the insulating layer, and

(e) an electron emitt