JPH07182970A - Manufacture of electron source - Google Patents

Abstract

PURPOSE:To uniformize the electron emission characteristics by applying constant voltage for a prescribed period and then applying voltage higher than the former level for electric communication treatment to form an electron emitting part of an electron emitting element. CONSTITUTION:An organometal solution is applied between element electrodes 5, 6 formed on the surface of an insulating substrate 1 to form an organometal thin film and then the film is heated and fired to form an electron emitting part composing thin film 2. Following that, forming voltage with a prescribed voltage waveform is applied between the electrodes 5, 6 to locally break, deform, or denature the film 2 and to form an electron emitting part 3. At the time when the forming treatment is carried out, the film 2 is moderately heated at constant voltage and then heated by applying voltage higher than the former constant voltage to form the part 3 within a short period. Consequently, even if the resistance of each element is not even, forming can be carried out surely without causing overload. As a result, the characteristics of each element can be made uniform.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing an electron source using a surface conduction electron-emitting device used in an image forming apparatus or the like.

[0002]

2. Description of the Related Art Conventionally, two types of electron emitters, a thermoelectron source and a cold cathode electron source, are known. The cold cathode electron source includes a field emission type, a metal / insulating layer / metal type, a surface conduction type electron emitting device (hereinafter referred to as SCE), and the like.

The SCE utilizes a phenomenon in which electron emission occurs when a current is passed through a thin film having a small area formed on a substrate in parallel with the film surface. As a typical configuration thereof, a pair of element electrodes are provided on an insulating substrate, a metal oxide thin film is formed so as to connect the electrodes, and the thin film is locally preliminarily subjected to an electric current treatment called forming. The thin film before and after forming is basically a fine particle film. An example of the configuration is shown in FIG. Conventionally,
DC, AC, and pulse waves are used for the SCE forming process. Particularly, in the case of pulse waves,
As disclosed in Japanese Patent Application Laid-Open No. 4-28139, a triangular wave or a rectangular wave has been used.

The SCE is a non-linear element in which the emission current rapidly increases by applying an element voltage equal to or higher than a certain voltage (threshold voltage), while the emission current is hardly detected below the threshold voltage. The emission current of SCE can be controlled by the device voltage, and the emission charge can be controlled by the application time of the device voltage. Further, various display devices are configured by combining an electron source including a plurality of SCEs and a phosphor that emits visible light by the electrons emitted from the electron source. However, since it is a self-luminous display device that can be manufactured relatively easily and has excellent display quality, it is expected as an image forming apparatus that replaces a CRT.

[0005]

In the conventional forming process described above, when the forming voltage is low, the element does not crack sufficiently, and when the forming voltage is high, an excessive current flows through the element. Therefore, the proper value of the forming voltage is narrow, and when there is variation in the element resistance for each element, the same forming voltage is applied and processed, and the shapes of the crack portion and the island structure which become the electron emitting portion vary from element to element, There is a problem that the device characteristics become non-uniform.

[0006]

A method of manufacturing an electron source in which a large number of surface conduction electron-emitting devices are arranged, wherein an energization process for forming an electron-emitting portion of the electron-emitting device is as follows. A method for manufacturing an electron source, which comprises applying a constant voltage V ₀ for a certain period of time t ₀ and then applying a voltage higher than the V _0, wherein V applied after V _{0 is} applied.
_{As the} voltage higher than ₀ , a constant voltage or a voltage that is an increasing function of time is used.

In the present invention, as described above, by applying the constant voltage V ₀ and the voltage higher than V ₀ in combination, even if the element resistance before forming varies from element to element, an excessive current flows through the element. Is prevented, or conversely, the current flowing through the element is prevented from becoming insufficient.

[0008]

【Example】

(Embodiment 1) FIG. 1 shows a forming voltage waveform in the first embodiment of the present invention. The forming waveform of FIG. 1 is
In the electron source manufacturing process shown in FIG. 2, a voltage is applied between the electrodes to form an electron emitting portion.

(1) After the insulating substrate 1 is thoroughly washed with a detergent, pure water and an organic solvent, a device electrode material is deposited by a vacuum vapor deposition method, a sputtering method or the like, and then on the surface of the insulating substrate 1 by a photolithography technique. Element electrodes 5 and 6 are formed on the substrate (a).

(2) An organometallic thin film is formed by applying an organometallic solution between the element electrodes 5 and the element electrodes 6 provided on the insulating substrate 1 and leaving them to stand. The organic metal solution means Pd, Ru, Ag, Au, Ti, In, C.
It is a solution of an organic compound containing a metal such as u, Cr, Fe, Zn, Sn, Ta, W, Pb as a main element. After that, the organometallic thin film is heated and baked, and is patterned by lift-off, etching or the like to form the electron emission portion forming thin film 2 (b). Although the organic metal solution coating method has been described here, the invention is not limited to this, and it may be formed by a vacuum vapor deposition method, a sputtering method, a chemical vapor deposition method, a dispersion coating method, a dipping method, a spinner method, or the like. There are also cases.

(3) Subsequently, a forming voltage having the voltage waveform shown in FIG. 1 is applied between the device electrodes 5 and 6 by a power source (not shown) to locally destroy or deform the electron emission portion forming thin film 2. The electron emitting portion 3 is formed by being altered (c).

In FIG. 1, t ₁ and t ₂ are the pulse width and pulse interval of the voltage waveform, preferably t ₁ is ₁ μs to ₁₀ μs.
ms, t ₂ are 10 μs to 100 ms, time t ₀ is 0.5 t _{1 to} 0.95 t ₁ , V ₀ is about 4 to ₁₀ V, peak voltage V ₁ is 1.1 V ₀ or more, and processing time is in a vacuum atmosphere. Was set appropriately for about several tens of seconds.

By performing the forming process using such a voltage waveform, the thin film 2 is formed at a constant voltage V ₀ .
After being gently heated, the electron emitting portion 3 is formed in a short time by applying a voltage higher than V ₀ . Therefore, even if there are variations in element resistance, forming can be performed reliably without overload.

(Embodiment 2) FIG. 3 shows a forming voltage waveform in the second embodiment of the present invention. The manufacturing process of this embodiment is basically the same as that of the first embodiment, but the high voltage portion is constituted by a constant voltage pulse, and the same effect as that of the first embodiment can be obtained.

(Embodiment 3) FIG. 4 shows a forming voltage waveform in a third embodiment of the present invention. The manufacturing process of this embodiment is basically the same as that of the first embodiment, but the high-voltage pulse is composed of voltage pulses that increase linearly, and the same effect as that of the first embodiment can be obtained.

[0016]

As described above, by performing a forming process by combining a constant voltage and a voltage higher than the constant voltage, even if there is a variation in resistance between elements, the process can be performed without excess or deficiency. It is possible to manufacture an electron source having uniform device characteristics.

[Brief description of drawings]

FIG. 1 is a diagram showing a forming voltage waveform according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram of a method of manufacturing an electron source according to the first embodiment of the present invention.

FIG. 3 is a diagram showing a forming voltage waveform in the second embodiment of the present invention.

FIG. 4 is a diagram showing a forming voltage waveform in a third embodiment of the present invention.

FIG. 5 is a diagram showing a configuration of an SCE according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Insulating substrate 2 Electron emission part forming thin film 3 Electron emission part 4 Thin film including an electron emission part 5, 6, element electrode

Claims (3)

[Claims] 1. A method of manufacturing an electron source comprising a large number of surface conduction electron-emitting devices arranged, wherein a constant voltage V ₀ is applied as an energizing process for forming an electron-emitting portion of the electron-emitting device. A method of manufacturing an electron source, characterized in that a voltage higher than V ₀ is applied after applying for a certain period of time t ₀ . Wherein after V ₀ applied, method of manufacturing an electron source according to claim 1, wherein applying a certain period higher fixed voltage than V _0. 3. The method of manufacturing an electron source according to claim 1, wherein the voltage applied to the thin film after applying V ₀ is an increasing function of time.