JP2992902B2 - Electron beam generator - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electron beam generator including an electron-emitting device and a conductive substrate for modulation.

[Prior art] Conventionally, as a device capable of emitting electrons with a simple structure, for example, MIElinson
Are known [Radio Eng. Electron. Phys., Vol. 10, 1290-1296]
P., 1965].

This utilizes the phenomenon that electron emission occurs when a current flows through a thin film having a small area formed on a substrate in parallel with the film surface, and is generally called a surface conduction electron-emitting device. .

Examples of the surface conduction electron-emitting device include a device using an SnO ₂ (Sb) thin film developed by Elinson et al., And a device using an Au thin film [G.
G. Dittmer: “Thin Solid F
ilms "), Vol. 9, p. 317, (1972)], using ITO thin film [M. Hartwell and C. G. Fonstad:“ I.E.E.E.
Dee Conf. ”(M. Hartwell and CGFonstad:“ I
EEE Trans. ED Conf. ") P. 519, (1975)], using a carbon thin film [Hisashi Araki et al .:" Vacuum ", Vol. 26, No. 1,
No.22, (1983)].

These surface conduction electron-emitting devices are: 1) obtain high electron emission efficiency; 2) are easy to manufacture because of their simple structure; 3) can form and form a large number of devices on the same substrate; ) It has the advantages of fast response speed, etc., and has the potential to be widely applied in the future.

FIG. 8 is a view showing a linear electron beam source using the surface conduction electron-emitting device. In this figure, 11 is an insulating substrate made of a glass substrate, 12 is a wiring electrode made of an Al thin film, 13 is an element electrode made of the above-mentioned material, 14 is an electron-emitting portion, and 15 is a line-shaped A modulation electrode 16 made of a metal thin plate for modulating the electron beam is an electron passage hole through which the emitted electrons pass.

In such a configuration, when a voltage of about 10 V is applied between the two wiring electrodes 12 under vacuum and a high voltage of about 1 KV is applied to the upper anode electrode plate (not shown), the electron emission portion 14 Electrons are emitted. By applying appropriate positive and negative voltages to the modulation electrode 15 for this electron emission,
The emitted electrons passing through the electron passage holes 16 can be controlled, and the ON / OFF control of the electrons reaching the upper anode electrode plate (not shown) can be performed.

[Problems to be Solved by the Invention] However, the linear electron source using the above-described surface conduction electron-emitting device has the following problems.

(1) Since it is difficult to align the electron passage hole 16 of the modulation electrode 15 with the electron emission portion 14, it is difficult to configure a long line electron source with a fine element pitch. Uneven emission of the source occurs.

(2) When the applied electrodes between the wiring electrodes 12 are raised to obtain emitted electrons of a large current, heat generation in the electron emitting portion 14 increases, and heat is generated on the insulating substrate 11 which is not efficient in heat conduction and heat radiation. And deformation due to thermal expansion occurs. Due to this deformation, a displacement between the electron passing hole 16 and the electron emitting portion 14 occurs,
The emission unevenness of the line electron source is more likely to occur.

That is, an object of the present invention is to provide an electron beam generator which has solved the above-mentioned problems.

[Means and Actions for Solving the Problems] The present invention made to achieve the above object provides an electron beam in which a surface conduction electron-emitting device is stacked on a conductive substrate made of metal via an insulator. In the generator, the conductive substrate and the surface conduction type electron-emitting device have separate independent voltage applying means, and the conductive substrate receives an electron beam emitted from the surface conduction type electron-emitting device. An electron beam generator is characterized in that a modulation voltage that modulates according to an information signal is applied.

The electron beam generator according to the present invention is further characterized in that the surface conduction type electron-emitting device is configured such that electrons are applied between electrodes arranged in parallel along the surface of the conductive substrate via the electrodes. A conductive member is connected to the conductive substrate, and the conductive member is disposed on the insulator on which the surface conduction electron-emitting device is disposed; The sheet material has a sheet resistance of 0.5 × 10 ⁵ Ω / □ to 1
A member having a range of × 10 ⁹ Ω / □, the conductive substrate being any of copper, aluminum, iron, or an alloy thereof; and a thickness of the insulator ranging from 1 μm to 200 μm. Having a plurality of the surface conduction electron-emitting devices, an electron emission voltage is sequentially applied to each surface conduction electron-emitting device, and the surface conduction electron-emitting device is applied to the conductive substrate. A modulation voltage is applied in synchronization with the application of the electron emission voltage, and each electron beam from each surface conduction electron-emitting device is sequentially modulated. An electron emission device is configured; an electron emission voltage is applied to the linear electron emission device, a modulation voltage is applied to the conductive substrate, and a plurality of electron beams from the linear electron emission device are collectively collected. Modulated .

That is, the basic technical idea of the present invention is as follows.
An electron-emitting device is arranged on a conductive substrate via an insulator film, and enables a modulation voltage signal of the electron-emitting device to be applied to the conductive substrate. This eliminates the need for precise positioning of the constituent members. Furthermore, even during high-current electron emission, the constituent members are formed on the same substrate, and the uniform heat radiation effect of the base ensures that a uniform line-shaped electron beam is always produced without displacement due to heat generation of the electron emission portion. Things.

Hereinafter, the configuration and operation of the present invention will be described in detail based on an example. In FIG. 1, reference numeral 1 denotes a conductive base made of a conductive base, and 2 denotes an insulator film formed of an insulating thin film, which is formed on the surface of the conductive base 1. Reference numerals 3a and 3b denote wiring electrodes made of a conductive thin film formed on the insulator film 2, and 4 denotes a wiring electrode 3
These are device electrodes which are connected to a and 3b and have a narrow electrode gap at a portion 1 in the figure. Reference numeral 5 denotes an electron emission portion in which an electron emission material is disposed in the electrode narrow gap.

Now, this device is placed under vacuum, and the device wiring electrodes 3a and 3b are
When an element voltage of several volts and an extraction voltage of several kilovolts are applied to an upper anode electrode plate (not shown), electrons are emitted from the electron emission portion 5. Although three electron emitting portions are arranged in the drawing for simplicity of illustration, a line-shaped electron emitting source (linear electron emitting element) can be formed by arranging a large number of electron emitting portions.

Further, the conductive substrate 1 has a negative number of 10 V or a positive number of 1 V.
By applying a modulation voltage of 0 V, the electron beam from the electron emission unit 5 can be turned on / off. In addition, by continuously changing the modulation voltage, the amount of the electron beam can be controlled continuously.

In addition to the above driving method, 0V or more than 10V as element voltage
Is applied to the element wiring electrodes 3a and 3b to control ON / OFF of the electron emission from the electron emission portion 5, and the modulation voltage applied to the conductive substrate 1 is continuously changed so that the amount of the electron beam is continuously changed. Can be controlled. Thus, the electron emission ON
The / OFF control and the control of the electron beam amount can be independently driven by voltages applied to the element wiring electrodes 3a and 3b and the conductive substrate 1, respectively. The reason that the electron beam can be controlled by the voltage applied to the conductive substrate 1 is based on the fact that the potential of the electron emitting portion 5 changes from plus to minus by the voltage of the modulation electrode, and the electron beam accelerates or decelerates. The surface conduction electron-emitting device used in the present invention emits electrons having an initial velocity of several volts into a vacuum. The present invention is extremely effective for modulation of such a device.

Hereinafter, each component member of the present embodiment will be described.
In FIG. 1, a conductive substrate 1 is made of a metal material whose surface is precisely polished. As materials, copper, aluminum, iron, etc. are suitable in terms of availability and cost.
It is also commonly used as a metal base substrate.
The thermal conductivity of these materials is around 100 Kcal / mhr-C Has heat dissipation effect. The insulator film 2 is preferably made of a coating glass material, an oxide thin film such as SiO ₂ by a vacuum deposition method, or another ceramic material. The thinner the thickness, the better the voltage applied to the modulation electrode, that is, the conductive substrate 1, can be reduced. The wiring electrodes 3a and 3b may be made of any material as long as the wiring electrodes 3a and 3b are formed to have sufficiently low electric resistance. The device electrode 4 is made of a metal thin film formed by a vacuum deposition method and photolithography, and an electrode gap is formed in a portion of the electron emission portion 5. The element electrode gap is preferably 0.1 μm to 10 μm. Further, the width of the device electrode (second
Figure: W) is preferably narrower, but actually 1 μm to 100 μm
m is preferred, and more preferably 1 μm to 10 μm. An ultrafine particle film is provided as an electron emitting material in an electrode gap of the electron emitting portion 5. The material of the ultrafine particles is preferably a metal material such as Pd, Ag, or Au, or an oxide material of SnO ₂ or In ₂ O ₃ , but is not limited thereto. As a forming method, besides the gas deposition method, for example, an organic metal is dispersed and applied,
Thereafter, a desired characteristic can be obtained even if an ultrafine particle film is formed in the electrode gap by heat treatment.

FIG. 7 shows that the element emission electrodes 10a and 10b are independently provided for each electron emission portion, compared with the drive configuration in which the electron emission in the above embodiment is such that all the linear elements are simultaneously modulated. In this configuration, each electron-emitting device can be individually modulated. This embodiment is the same as the above-described embodiment such as constituent members, but in driving, an electron emission voltage is sequentially applied to each element wiring electrode to emit electrons in a dot-sequential manner. At this time, by applying a modulation voltage to the conductive substrate 1 in synchronization with the electron emission voltage pulse,
A linear electron source in which the electron beam is modulated and controlled in a point-sequential manner can be obtained.

The surface conduction electron-emitting device used in the present invention is 100
Since driving can be performed in response to a voltage pulse of picosecond or less, a high-density linear electron source can be modulated in a point-sequential manner.

In the configuration described above, since the conductive substrate 1 having the modulation function and the electron emitting portion 5 are formed as the same body, mutual displacement of the members due to thermal expansion caused by heat generation at the time of electron emission of the electron emitting portion 5. Does not occur. Furthermore, since the conductive substrate 1 as a whole functions as a modulation electrode, it has a simple structure in which the alignment itself between the electron-emitting portion 5 and the conductive substrate 1 is basically unnecessary. Further, since the thermal conductivity of the conductive substrate 1 is large, it is possible to eliminate the local heat storage of the electron-emitting portion 5 due to heat generation, which is very useful for a large-current electron-emitting portion.

EXAMPLES Examples of the present invention will be described below.

Embodiment 1 FIG. 1 is a configuration diagram of an electron beam generator of the present embodiment. 1 is a conductive substrate, 2 is an insulator film, 3a and 3b are wiring electrodes,
4 is a device electrode, and 5 is an electron emission part.

In this embodiment, the modulation electrode between the electron-emitting device and the phosphor of the conventional example shown in FIG. 8 is disposed below the electron-emitting portion 5, that is, as a conductive substrate, and the electron-emitting device and the conductive substrate 1 are formed of an insulating film. 2 are integrally formed.

FIG. 2 is a cross-sectional view in the element column direction of FIG. 1 and shows a method of manufacturing the electron beam generator of the present embodiment.

 Next, a method for manufacturing the device will be described.

. The aluminum substrate (conductive substrate 1) whose surface has been precisely polished is sufficiently washed, and SiO ₂ (insulating film 2) is 10 μm thick by vapor deposition.
Formed.

. Next, the element electrode 4 and the wiring electrodes 3a and 3b were made of a Ni material by vapor deposition and photolithographic etching. The length (FIG. 1: l) corresponding to the electron-emitting portion 5 is 300 μm, the device electrode width (FIG. 2: W) is 8 μm, and the device electrode gap (FIG. 2: G).
And the arrangement pitch of the electron-emitting portions 5 was 2 mm.

. Next, using the gas deposition method, the electron emission portions 5 are formed.
A Pd ultrafine particle film having a diameter of about 100 mm was provided in a portion to be formed.

The device obtained as described above was placed in a vacuum, an anode electrode plate (not shown) was placed at a distance of 5 mm, and an extraction voltage of 0.8 KV to 1.5 KV was applied. Further, a voltage of 14 V was applied between the pair of wiring electrodes 3a and 3b, and electrons were emitted from the electron-emitting devices arranged in a line. Here, a modulation voltage was applied to the conductive substrate 1, and the electron beam was turned off at -40V or less and turned on at 30V or more. The amount of the electron beam could be continuously changed between 40V and 30V.

Furthermore, when 100 electron-emitting devices are arranged in a line,
In the case of a conventional insulating substrate made of glass, a substrate temperature of 12
The temperature rose to about 0 ° C., and at this time, fluctuation of the electron beam occurred partially. However, in this embodiment, by making appropriate contact between the conductive substrate and the vacuum vessel, it was possible to limit the temperature rise to about 60 ° C. and to obtain a uniform electron beam.

Embodiment 2 FIG. 3 is a configuration diagram of an electron beam generator according to a second embodiment.

FIG. 4 is a sectional view in the element column direction of FIG. In this embodiment, the modulation electrode 6 connected from the conductive substrate in the first embodiment is arranged in the electron emission surface.

The manufacturing method of the present embodiment shown in FIG. 3 can be formed by the same vapor deposition and etching method as in the first embodiment, and thus the description is omitted. The shape of each component was manufactured in the same manner as in Example 1. In FIG. 4, the interval (S) between the element electrode 4 and the modulation electrode 6 was 10 μm.

In this embodiment, the voltage applied to the conductive substrate 1 is −25.
The electron beam was turned off at V or less and turned on at 10 V or less. Further, the amount of the electron beam could be continuously controlled at -25 V to 10 V as in the first embodiment.

In the present embodiment, as in the case of the first embodiment, the heat storage of the electron emission portion was reduced, and a uniform linear electron beam could be obtained.

Embodiment 3 FIG. 5 is a configuration diagram of an electron beam generator according to a third embodiment. FIG. 6 is an explanatory view of a manufacturing method in a cross section in the element column direction of FIG. Next, the manufacturing method of this embodiment will be described. Reference numeral 8 denotes a contact hole.

. Same as the manufacturing method of the first embodiment. However, the thickness of the insulator film 7 was 3 μm.

. A contact hole 8 is provided by an etching method.
The contact hole is located at the position sandwiching the element electrode 4 with the insulator film 7.
Created by removing. That is, the conductive substrate 1 is exposed through the contact hole.

. Same as the manufacturing method in the first embodiment.

. Next, organic palladium is applied to the entire surface of the substrate by dipping. This was baked at 300 ° C. for 1 hour to deposit fine palladium particles 9 on the entire surface of the substrate. As organic palladium, Okuno Pharmaceutical Co., Ltd. CCP-4230 was used. In this process, not only the ultrafine particles mainly composed of palladium, which is an electron emitter, are provided between the opposing device electrodes 4, but also a conductive material is formed on the inner wall of the contact hole 8 and the surface of the insulator film 7. Fine particles are precipitated. At this time,
The sheet resistance of the insulator film surface is 0.5 × 10 ⁵ Ω / □ to 1 × 10 ⁹
Ω / □ is suitable, and more preferably 1 × 10 ⁵ Ω / □ to 1 × 10 ⁷ Ω / □.
Is optimal.

The size of the contact hole 8 in the present embodiment is preferably approximately the same as the length of the electron-emitting portion 5 as shown in FIG.
The distance S between the contact hole and the device electrode is 10 μm or more.
500 μm is preferred, and more preferably 25 μm to 100 μm.

In this embodiment, when a voltage is applied to the conductive substrate 1, a current flows through the contact hole 8 to change the potential on the surface of the insulating film, and controls the surface potential of the insulating film near the element electrode 4.

In this embodiment, the voltage applied to the conductive substrate 1 is −
The electron beam could be turned off at 25V or less and turned on at 10V or more.

In the present embodiment, as in the case of the first embodiment, the heat storage of the electron emission portion was reduced, and a uniform linear electron beam could be obtained.

Embodiment 4 FIG. 7 is a configuration diagram of an electron beam generator according to a fourth embodiment.

In the present embodiment, the wiring electrodes in the first embodiment are made independent for each electron-emitting device. The manufacturing method of this embodiment shown in FIG. 7 is the same as that of the first embodiment. In the present embodiment, a voltage pulse of 14 V is sequentially applied to the wiring electrodes 10 a and 10 b of each electron-emitting device, and a modulation voltage of −40 V to 30 V is applied to the conductive substrate in synchronization with the voltage pulse. Each time, the ON / OFF control of the electron beam and the continuous change of the electron beam amount were enabled. In the present embodiment, as in the case of the first embodiment, the heat storage of the electron emission portion was reduced, and a uniform linear electron beam could be obtained. In addition, independent modulation control of each electron-emitting device of this embodiment is performed by:
Embodiments 2 and 3 were also realized by changing the shape of the wiring electrode and the applied driving voltage.

[Effects of the Invention] As described above, by providing an electron source having a very simple structure in which an electron-emitting device is arranged on an insulator film on a conductive substrate, (1). Since the electron-emitting device substrate itself becomes the modulation electrode,
It eliminates the need for precise positioning of the constituent members, and allows a long line electron source to be formed in a simple process.

(2). Even at the time of high-current electron emission, the constituent members are formed on the same substrate, and there is no displacement due to the heat generation of the electron-emitting portion due to the good heat radiation effect of the base, so that a uniform linear electron beam can always be obtained. This has the effect.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an embodiment of the present invention and a first embodiment. FIG. 2 is a sectional view of an element showing a first embodiment of the present invention. FIG. 3 is a perspective view showing a second embodiment of the present invention. FIG. 4 is a sectional view of an element showing a second embodiment of the present invention. FIG. 5 is a perspective view showing a third embodiment of the present invention. FIG. 6 is a sectional view of an element showing a third embodiment of the present invention. FIG. 7 is a perspective view showing a fourth embodiment of the present invention. FIG. 8 is a perspective view showing a conventional example. DESCRIPTION OF SYMBOLS 1 ... Conductive base 2, 7 ... Insulator film 3a, 3b, 10a, 10b, 12 ... Wiring electrode 4, 13 ... Device electrode 5, 14 ... Electron emission part 6, 15 ... Modulation electrode 8 ... ... Contact hole 9 ... Palladium fine particles 11 ... Insulating substrate 16 ... Electron passage hole

Continuation of the front page (72) Inventor Haruhito Ono 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (72) Inventor Hidetoshi Suzuki 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (56) References JP-A-60-131739 (JP, A) JP-A-60-107244 (JP, A) JP-A-1-173553 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) H01J 1 / 30,3 / 08 H01J 29 / 04,29 / 52 H01J 31/12-31/15

Claims (9)

(57) [Claims] 1. An electron beam generator in which a surface conduction electron-emitting device is stacked on a conductive substrate made of metal via an insulator, wherein the conductive substrate, the surface conduction electron-emitting device, Has an independent voltage application means, and a modulation voltage for modulating an electron beam emitted from the surface conduction electron-emitting device according to an information signal is applied to the conductive substrate. Line generator. 2. The device according to claim 1, wherein the surface conduction type electron-emitting device has an electron-emitting portion to which a voltage is applied via electrodes between the electrodes arranged along the surface of the conductive substrate. The electron beam generator according to claim 1. 3. A conductive member is connected to the conductive substrate, and the conductive member is disposed on the insulator on which the surface conduction electron-emitting device is disposed. The electron beam generator according to claim 1. 4. The conductive member has a sheet resistance of 0.5 × 10 ^5.
4. The electron beam generator according to claim 3, wherein the member has a range of Ω / □ to 1 × 10 ⁹ Ω / □. 5. The electron beam generator according to claim 1, wherein said conductive substrate is made of one of copper, aluminum, iron, and an alloy thereof. 6. The electron beam generator according to claim 1, wherein said insulator has a thickness in a range of 1 μm to 200 μm. 7. A plurality of said surface conduction electron-emitting devices,
An electron emission voltage is sequentially applied to each surface conduction electron-emitting device, and a modulation voltage is applied to the conductive substrate in synchronization with the application of the electron emission voltage to each surface conduction electron-emitting device. The electron beam generator according to any one of claims 1 to 6, wherein each electron beam from the surface conduction electron-emitting device is sequentially modulated. 8. An electron beam generator according to claim 7, wherein a plurality of said surface conduction electron-emitting devices are connected to form a linear electron-emitting device. 9. A method in which an electron emission voltage is applied to said linear electron-emitting device, and a modulation voltage is applied to said conductive substrate, so that a plurality of electron beams from said linear electron-emitting device are collectively modulated. The electron beam generator according to claim 8, wherein: