JP2956107B2 - Electron-emitting device - Google Patents

Description

The present invention relates to an electron microscope, an electron beam exposure apparatus, and a CRT.
The present invention relates to an electron-emitting device that can be used as an electron source of various electron beam application devices.

2. Description of the Related Art Conventionally, a hot cathode that emits thermoelectrons has been used as an electron source in electron microscopes, electron beam exposure apparatuses, CRTs, and the like. However, the hot cathode requires a heating means for heating the cathode itself, and has problems such as energy loss accompanying heating. Therefore, in recent years, research has been conducted on an electron-emitting device that does not require heating, that is, a so-called cold cathode, and several types of electron-emitting devices have been proposed.

For example, a reverse bias voltage is applied to a PN junction to cause an avalanche breakdown phenomenon to emit electrons to the outside of the element, or a needle-shaped metal in which electric field concentration is likely to occur, A field emission type electron-emitting device that applies a voltage to locally generate a high-density electric field and emits electrons from the metal to the outside of the device, or a three-layer structure of a metal layer-insulator layer-metal layer, There is a MIM type electron-emitting device that emits electrons that have passed through the insulator layer by a tunnel effect to the outside of the device by applying a voltage to the two metal layers.

As the field emission type electron-emitting device, for example, Journal of Applied Physics, Vol. 39, No. 7,
3504, 1968 (Journal of Applied Physics, Vo
l39, No. 7, P3504, 1968). Hereinafter, the outline of the electron-emitting device will be described in the fourth.
This will be described with reference to the cross-sectional views shown in the drawings.

As shown in FIG. 4, a lower electrode 42 is formed on a substrate 41. On the lower electrode 42, an electron emitting portion 43 having a shape in which electric field concentration easily occurs is formed, and an insulator layer 44 is formed around the electron emitting portion 43. On the insulator layer 44, an extraction electrode 45 is formed.

The power supply 46 is connected so that the extraction electrode 45 is positive and the lower electrode 42 is negative, and a voltage higher than a predetermined voltage determined by the material of the electron emission portion 43 is applied, so that the electron emission portion where the electric field is concentrated 43 can emit electrons.

Further, as the MIM type electron-emitting device, for example, a configuration described in Japanese Patent Application Laid-Open No. 63-6717 is known.
Hereinafter, an outline of the electron-emitting device will be described with reference to a perspective view shown in FIG.

As shown in FIG. 5, a strip-shaped metal layer 52 is formed on a substrate 51, and the metal layer 52 is covered with an insulator layer 53. A strip-shaped metal layer 54 is formed on the insulator layer 53 in a direction orthogonal to the metal layer 52.

Then, by applying a predetermined voltage between the metal layer 54 and the metal layer 52 with the metal layer 54 being positive and the metal layer 52 being negative, electrons can be emitted from a region where the two intersect.

In addition, as an arrayed MIM type electron-emitting device,
For example, Japan Display '86, 512 pages (Japa
n Display '86, P512) is known. Hereinafter, this array-like electron-emitting device will be described in the sixth.
Description will be made with reference to the perspective view shown in the figure.

As shown in FIG. 6, a plurality of upper electrodes 62 are formed on a substrate 61.
, and the lower electrodes 63a, 63b, 63c,... cross each other, and at each crossing portion, for example, an electron-emitting portion 64 as shown in FIG. 4 is formed.

Then, by applying a predetermined voltage to the upper electrode and the lower electrode sharing a desired intersection where electrons are to be emitted, for example, 62a and 63a, electrons are emitted from the electron emission portion 64 at the intersection of both. be able to.

However, if the electron-emitting devices are arrayed to emit electrons from a large number of electron-emitting regions, a large number of upper electrodes 62a, 62b, 62c,... And lower electrodes 63a, 63b, as apparent from FIG. , 63c, ... must be formed,
There are problems such as complicated wiring for driving.

Then, in order to solve the above problem, Japanese Patent Application Laid-Open No.
Has been proposed.
Hereinafter, this array-shaped electron-emitting device will be described with reference to the cross-sectional view shown in FIG.

As shown in FIG. 7, a plurality of lower electrodes 72
Is provided, a light switching layer 73 is formed on the lower electrode 72, a plurality of conductive layers 74 serving as electron emission regions are provided on the light switching layer 73, and the conductive layer 74 is covered with an insulating thin film 75. I have. An upper electrode 76 is formed on the insulating thin film 75, an insulating layer 77 is formed on the upper electrode 76 around the electron emission region, and an acceleration electrode 78 is formed on the insulating layer 77.

Then, a voltage is applied to the lower electrode 72 and the upper electrode 76 by a power supply 79, light 80 is incident from the lower electrode 72 side, and the light switching layer 73 irradiated with the light is changed from an electrical high resistance state to a low resistance state. State, and the electrode 76 on the opposite side of the light incident area
Electrons can be emitted from the surface.

Problems to be Solved by the Invention However, among the above-described conventional array-shaped electron-emitting devices,
The former configuration has a problem that the driving wiring is complicated as described above. On the other hand, in the latter configuration in which the optical switching layer is interposed, electrons can be emitted from a desired electron emission region by light irradiation. However, due to crosstalk in the optical switching layer due to diffusion of light at the time of light irradiation, adjacent electrons are emitted. There has been a problem that there is a possibility that a malfunction of emitting electrons from the emitting portion may occur.

The present invention solves the above-mentioned problems of the prior art, and can simplify a drive wiring and can prevent malfunction of an adjacent electron emission region. The purpose is to provide.

Means for Solving the Problems The technical solution of the present invention for achieving the above-mentioned problem is to firstly provide a substrate having transparency to predetermined light, a substrate formed on the substrate, and A first conductor layer which is opaque to the first conductor layer having a plurality of openings, and a photoconductor layer formed in contact with the first conductor layer in each of the openings,
A second conductor layer formed in contact with the photoconductor layer; an insulator layer formed around the photoconductor layer and the second conductor layer; Formed on the layer,
It has an insulator layer for transmitting electrons and a third conductor layer formed on the insulator layer for emitting electrons.

Second, a substrate having a predetermined light-transmitting property, a transparent first conductor layer formed on the substrate, and at least upper and lower sides of the transparent first conductor layer. A light-shielding body layer formed on one side and opaque to predetermined light and having a plurality of openings, and in contact with the transparent first conductive layer;
A photoconductor layer formed corresponding to each opening of the light-shielding body layer; a second conductor layer formed in contact with the photoconductor layer; An insulator layer formed around the second conductor layer, an insulator layer formed on the second conductor layer and transmitting electrons, and an insulator layer formed on the insulator layer and And a third conductive layer for emission.

Third, a substrate having transparency to predetermined light, a conductive layer formed on the substrate, opaque to predetermined light, and having a plurality of openings, A photoconductor layer formed in contact with the conductor layer, an insulator layer formed around the photoconductor layer, an electron-emitting portion formed on the photoconductor layer, It has an insulator layer formed around the electron emitting portion, and an extraction electrode formed on the insulator layer.

Operation Therefore, according to the first technical solution, a predetermined voltage is applied to the first conductor layer and the third conductor layer in advance, and a first voltage corresponding to a desired electron emission region from the substrate side is applied. The photoconductor layer in the electron emission region is electrically connected from the electrically insulated state by irradiating the photoconductor layer from the opening portion of the first conductor layer independently or for a predetermined time sequentially with time. State, electrically connecting the first conductor layer to the second conductor layer in the electron emission region, and causing electrons to be emitted from the third conductor layer for a predetermined time by a tunnel phenomenon of the insulator layer. be able to.

According to the second technical solution, a predetermined voltage is applied between the transparent first conductor layer and the third conductor layer to correspond to a desired electron emission region from the substrate side. The photoconductor layer in the electron emission region is changed from an electrically insulated state to an electrically conductive state by irradiating the photoconductor layer from the opening of the light shielding layer independently or for a predetermined time in a time sequence. Electrically connecting the first conductor layer and the second conductor layer in the electron emission region, and allowing the third conductor layer to emit electrons for a predetermined time due to a tunnel phenomenon of the insulator layer. it can.

According to the third technical solution, a predetermined voltage is applied between the conductor layer and the extraction electrode, and light is emitted from the opening of the conductor layer corresponding to a desired electron emission region from the substrate side. By irradiating the conductor layer independently or for a predetermined time in a time sequence, the photoconductor layer in the electron emission region is changed from an electrically insulating state to an electrically conductive state, and the conductor layer and the electron emission region are Can be electrically connected, and electrons can be emitted from this electron emission portion for a predetermined time.

Embodiments Hereinafter, embodiments of the present invention will be described with reference to the drawings.

First, a first embodiment of the present invention will be described. First
FIG. 1 is a sectional view showing an electron-emitting device according to a first embodiment of the present invention.

As shown in FIG. 1, a first conductor layer 2 which is opaque to predetermined light to be used is formed on a substrate 1 having transparency to predetermined light to be used. Body layer 2
Has a plurality of apertures 3. A photoconductor layer 4 is formed in each opening 3 in contact with the first conductor layer 2, and a second conductor layer 5 is formed on the photoconductor layer 4 in contact therewith. The outer periphery of each second conductor layer 5 is opposed to the first conductor layer 2 on the outer periphery of the opening 3. An insulator layer 6 is formed around the photoconductor layer 4 and the second conductor layer 5 on the first conductor layer 2, and is electrically separated into electron emission regions. The insulator layer 6 is desirably opaque to excitation light that causes the photoconductor layer 4 to have electrical conductivity.
A thin insulator layer 7 for electron transmission is formed on the second conductor layer 5 and the insulator layer 6, and a third conductor layer 8 for electron emission is formed on the insulator layer 7. I have. The insulator layer 7 causes electrons to pass through the third conductor layer 5
Since it is a portion that transmits to the conductor layer 8, the thinner the layer is formed, the higher the tunneling probability becomes, which is preferable. However, it is practically about 3 to 20 nm. Similarly, the third conductor layer 8 is preferably as thin as possible. However, in practice, the thickness is 5 to 40 nm in consideration of conductivity.
It is about. Further, a third conductor layer 8 for emitting electrons is formed so as to cover the second conductor layer 5, and serves as an upper electrode of the electron-emitting device. Even with the above configuration, the basic function as an electron-emitting device is satisfied, but an insulator layer 9 is further formed on the third conductor layer 8 so as to avoid over the second conductor layer 5 at the outer periphery of the electron emission region. Then, an extraction electrode 10 is formed on each insulator layer 9.

The operation of the above configuration will be described below.

A predetermined voltage required to cause electron emission by the power supply 11 is applied so that the third conductor layer 8 is positive and the first conductor layer 2 is negative, and electron emission is performed from the substrate 1 side. A predetermined light is radiated to the opening 3 corresponding to a portion to be made independently or in a time sequence for a predetermined time. As a result, only the irradiated photoconductor layer 4 of the opening 3 is irradiated, and the irradiated photoconductor layer 4 is changed from an electrically insulated state to an electrically conductive state. As a result, the first conductor layer 2 is electrically connected to the second conductor layer 5 in the electron emission region where electrons are to be emitted through the irradiated photoconductor layer 4 to emit electrons. A predetermined voltage is applied by the power supply 11 between the second conductive layer 5 and the third conductive layer 8 in the electron emission region to be emitted, and the third conductive layer in the electron emission region to emit electrons by a tunnel phenomenon. Electrons can be emitted from the body layer 8. At this time, by forming the second insulator layer 9 and the extraction electrode 10 on the third conductor layer 8 as described above, electrons can be more easily emitted, and beam control of emitted electrons can be performed. Can be.

Next, a second embodiment of the present invention will be described. Second
FIG. 4 is a sectional view showing an electron-emitting device according to a second embodiment of the present invention.

As shown in FIG. 2, a light-shielding layer 16 that is opaque to predetermined light is formed on a substrate 15 that is transparent to predetermined light to be used. It has a part 17. A transparent first conductor layer 18 is formed on the light shielding body layer 16 and the substrate 15, and a photoconductor layer 19 corresponding to each opening 17 is formed on the transparent first conductor layer 18. Are formed. A second conductive layer 20 is formed on and in contact with each photoconductive layer 19, and the outer peripheral portion of each second conductive layer 20 is formed of a transparent first conductive layer around the opening 17. It is facing the body layer 18. A photoconductor layer 19 is provided on the transparent first conductor layer 18.
And an insulator layer 21 formed around the second conductor layer 20 to be electrically separated into electron emission regions. On the second conductor layer 20 and the insulator layer 21, a thin (film thickness) for electron transmission is formed.
An insulator layer 22 is formed, and a third conductor layer 23 for emitting electrons is formed on the insulator layer 22. Furthermore,
If necessary, an insulator layer 24 is formed on the third conductor layer 23 so as to avoid the second conductor layer 20 at the outer periphery of the electron emission region, and an extraction electrode 25 is formed on each insulator layer 24. Have been.

The operation of the above configuration will be described below.

A predetermined voltage is applied by a power supply 26 so that the third conductor layer 23 is positive and the transparent first conductor layer 18 is negative,
A light-shielding layer corresponding to a portion where electrons are to be emitted from the substrate 15 side
A predetermined light is radiated to the 16 apertures 17 independently or in time sequence for a predetermined time. As a result, only the photoconductor layer 19 at a necessary portion in the light shielding layer 16 is irradiated, and thereafter, electrons can be emitted only from a desired electron emission region by the same operation principle as in the first embodiment.

In the above embodiment, the case where the light shielding layer 16 is formed below the transparent first conductive layer 18 has been described, but the light shielding layer 16 is formed above the transparent first conductive layer 18. The same effect could be obtained by forming.

Next, a third embodiment of the present invention will be described. Third
FIG. 7 is a sectional view showing an electron-emitting device according to a third embodiment of the present invention.

As shown in FIG. 3, a conductive layer 32 that is opaque to predetermined light is formed on a substrate 31 that transmits light to be used, and the conductive layer 32 has a plurality of apertures. It has a part 33. A photoconductor layer 34 is formed in each opening 33 in contact with the conductor layer 32, and an insulator layer 35 is formed on the conductor layer 32 around the photoconductor layer 34. An electron emission portion 36 is formed over the photoconductor layer 34 so as to easily cause the concentration of an electric field. On the insulator layer 35, an insulator layer 37 is formed around the electron emission portion 36.
Are formed, and an extraction electrode 38 is formed on the insulator layer 37. Since the configuration of the present embodiment is a so-called field emission type, it is desirable that the electron-emitting portion 36 uses a material having a high melting point and a low work function, for example, Mo, LaB ₆ , ZrC or the like.

In the present embodiment, a predetermined voltage is applied by a power source 39 so that the extraction electrode 38 is positive and the conductor layer 32 is negative, and the desired electron emission region is formed on the same principle as in the first embodiment. Can emit electrons.

Example 1 In FIG. 1, glass was used as the substrate 1,
On this substrate 1, a first conductor layer 2 made of a 300-nm-thick Al vapor-deposited film having 10 × 10 holes 3 with a diameter of 0.5 mm and a pitch of 2 mm was formed. Next, a photoconductor layer 4 having a thickness of 0.6 mm and a thickness of 500 nm, for example, CdSe, CdS, ZnS or the like was formed in the opening 3 having a diameter of 0.5 mm. Next, for example, SiO ₂ , Al ₂ O _3, or the like is formed as an insulator layer 6 around the photoconductor layer 4 on the first conductor layer ₂ , and then formed on the photoconductor layer 4. As a third conductor layer 5 having a diameter of 0.8 mm in contact therewith, for example, Al, Mo, LaB ₆ , ZrC
Etc. were formed. Next, Al ₂ O ₃ , SiO ₂ , Si ₃ N _{4, and the} like were formed on the insulator layer 6 and the second conductor layer 5 as a thin insulator layer 7 to a thickness of about 10 nm. Next, a third conductive layer 8 on the insulator layer 7, for example, Au, ZrC, a LaB _6, etc. 10~15n
An electron-emitting device was manufactured by forming the film with a thickness of m. And
While applying a voltage of 10 to 15 V between the third conductor layer 8 and the first conductor layer 3, a He-Ne laser beam is applied from the glass substrate 1 side to the opening 3 corresponding to a desired electron emission region. As a result, there was no malfunction due to crosstalk, and electrons could be emitted only from the portion corresponding to the opening 3 irradiated with the He-Ne laser beam on the third conductor layer 8 side.

Example 2 In FIG. 2, first, as a light-shielding body layer 16 having a hole 17 of φ0.5 mm on a glass substrate 15, for example, G
e, Si, etc. were formed. Next, after forming a transparent first conductor layer 18 such as ITO or SnO ₂ on the light-shielding body layer 16 and the glass substrate 15, an electron-emitting device was manufactured in the same manner as in Example 1 above. Then, as in the first embodiment, while applying a voltage to the third conductive layer 23 and the transparent first conductive layer 18,
As a result of performing light irradiation for each electron emission region from the 15th side, there was no malfunction due to crosstalk, and electrons could be emitted only from the desired electron emission region.

Embodiment 3 In FIG. 3, first, a first conductor layer made of an Al vapor-deposited film is formed on a glass substrate 31 in the same manner as in the first embodiment.
32, a photoconductor layer 34 made of CdSe, CdS, ZnS, etc., and an insulator layer 32 made of SiO ₂ were formed. Next, on the insulator layer 35, as an insulator layer 37 around the electron emission portion, SiO ₂ is formed to a thickness of about 1 μm by a photo process, and a lead electrode 38 is formed thereon.
Was formed with a thickness of 300 nm. Then, the co-deposited method for oblique deposition and vertical deposition, Mo over the photoconductor layer 34, thereby forming an electron-emitting portion 36 consisting of LaB _6, etc.. Then, while applying a predetermined voltage to the extraction electrode 38 and the conductor layer 32, light irradiation was performed from the glass substrate 31 side to the opening 33 corresponding to the desired electron emission region. Was able to emit electrons.

Effects of the Invention As described above, according to the present invention, a photoconductor layer is provided in a plurality of openings that can transmit predetermined light, and one side of the photoconductor layer is brought into contact with the conductor layer. By contacting the other side of the photoconductor layer with an independent conductor layer corresponding to the photoconductor layer, or an electron emitting portion, and irradiating light to an opening corresponding to a desired electron emitting region, The photoconductor layer in the electron emission region is changed from an electrically insulating state to an electrically conductive state, and the conductor layer is electrically connected to the conductor layer or the electron emission portion of the electron emission region, and only the electron emission region is used. To emit electrons. Therefore,
Driving wiring can be simplified, and crosstalk can be eliminated to prevent malfunction of adjacent electron emission regions.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an electron-emitting device according to a first embodiment of the present invention, FIG. 2 is a sectional view showing an electron-emitting device according to a second embodiment of the present invention, and FIG. FIG. 4 is a sectional view showing an example of a conventional electron-emitting device, FIG. 5 is a perspective view showing another example of a conventional electron-emitting device, and FIG. Is a perspective view showing another example of the conventional electron-emitting device, and FIG. 7 is a sectional view showing still another example of the conventional electron-emitting device. DESCRIPTION OF SYMBOLS 1 ... board | substrate, 2 ... 1st conductor layer, 3 ... opening part, 4
... photoconductor layer, 5 ... second conductor layer, 6 ... insulator layer, 7 ... insulator layer, 8 ... third conductor layer, 9 ... insulator layer, 10 ... ... Extraction electrode, 15 ... Substrate, 16 ... Light shielding layer, 17 ... Opening, 18 ... Transparent first conductor layer, 19 ...
... Photoconductor layer, 20 ... Second conductor layer, 21 ... Insulator layer, 22 ... Insulator layer, 23 ... Third conductor layer, 24 ... Insulator layer, 25 ... Leader electrode, 31 substrate, 32 conductor layer, 33 aperture, 34 photoconductor layer, 35 insulator layer, 36 electron emission section, 37 insulator layer , 38 ... Extractor electrode.

Continuation of front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H01J 1/30

Claims (3)

(57) [Claims] A substrate having transparency to predetermined light;
A first conductive layer formed on the substrate, opaque to predetermined light, and having a plurality of openings, and formed in contact with the first conductive layer at each of the openings. A photoconductor layer, a second conductor layer formed in contact with the photoconductor layer, an insulator layer formed around the photoconductor layer and the second conductor layer, An electron formed on the second conductor layer and having an insulator layer for transmitting electrons; and a third conductor layer formed on the insulator layer for emitting electrons. Emission element. 2. A substrate having transparency to predetermined light,
A transparent first conductive layer formed on the substrate, and a plurality of openings formed on at least one of the upper side and the lower side of the transparent first conductive layer and opaque to predetermined light; A light-shielding layer having a hole, a photoconductor layer formed in contact with the transparent first conductive layer and corresponding to each opening of the light-shielding layer; A second conductor layer formed in contact, an insulator layer formed around the photoconductor layer and the second conductor layer, and a second conductor layer formed on the second conductor layer; An electron-emitting device comprising: an insulator layer for transmitting electrons; and a third conductor layer formed on the insulator layer for emitting electrons. 3. A substrate having transparency to predetermined light,
A conductive layer formed on the substrate, opaque to predetermined light, and having a plurality of openings, and a photoconductor layer formed in contact with the conductive layer at each of the openings. An insulator layer formed around the photoconductor layer, an electron-emitting portion formed on the photoconductor layer, an insulator layer formed around the electron-emitting portion, An electron-emitting device comprising: an extraction electrode formed on a layer.