JPH01112632A - Electron emitting element and its manufacture - Google Patents

Abstract

PURPOSE:To enhance the electron emitting characteristic and facilitate manufacture of a surface conductive electron emitting element by sensing the current flowing in a film, controlling the impression voltage, and forming an electron emitting part. CONSTITUTION:A voltage is impressed on a film 3 on a base board 4 through electrodes 1, 2, and an electron emitting part 5 is formed. In this process, impression voltage is raised while the current flowing in the film 3 is sensed, and when the current value has decreased, the voltage is fixed for a certain period of time, and thereafter the processing is completed when the current value of amperage has taken a certain value. The emission efficiency of electron emitting element by this method is large, and the duration of emission is long. The time for forming the electron emitting part is short, and the power consumption is small. As manufacture can be made in optimum condition to suit the element, the allowance of shape and dimension at the time of forming the film becomes large.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a surface conduction type electron-emitting device and a method for manufacturing the same.

[Prior Art] Conventionally, as an element that can emit electrons with a simple structure,
For example, M, 1Elins
The cold cathode device announced by Radio Eng, Electron, etc. is known.

Phys, ) Volume 10, pp. 1290-129G,
1965].

This device utilizes the phenomenon that electrons are emitted when a current is passed through a small-area thin film formed on a substrate parallel to the film surface, and is generally called a surface conduction type emission device.

This surface conduction type emission device uses the 5n02 (Sb) thin film developed by Ellingson et al.
u Thin film [G, Dittmer “Thin Solid Films” (G, Dittmer: “Th1n
5solid Films”), Volume 9, page 317,
(1972) ], ITO thin film [M, Hartwell and C, G, F.
onstad: ” IEEE Trans, ED C
onf, ”) p. 519, (1975)], by carbon thin film [Hisashi Araki et al.: “Vacuum”, Vol. 26,
No. 1, p. 22, (1983)].

Typical device configurations of these surface conduction layer emitting devices are shown in the fourth section.
As shown in the figure. In FIG. 4, 11 and 12 are electrodes for obtaining electrical connection, 13 is a thin film formed of an electron-emitting material, 14 is a substrate, and 15 is an electron-emitting portion.

Conventionally, in these surface conduction layer emitting devices, an electron emitting portion is formed in advance by an electrical heating process called forming before electron emission. That is, by applying a constant voltage or a voltage that increases at a constant rate over time between the electrodes 11 and 12, the thin film 13 is energized, and the Joule heat generated thereby causes the thin film I to
The electron emitting function is obtained by locally destroying, deforming, or altering the electron emitting part 3 to form an electron emitting part 15 that is in an electrically high resistance state.

[Problems to be solved by the invention] However, in the above conventional example, when forming is performed by applying a constant voltage, the electron emitting part is likely to be damaged, and the electron emission efficiency, lifespan, and stability of the emission current are affected. Characteristics such as these deteriorated, and variations among the elements were large. In addition, if forming is performed by increasing the applied voltage at an extremely small rate in order to avoid these drawbacks, it will take a very long time to complete forming, and the consumption for forming will increase accordingly. This also had the disadvantage of increasing the amount of electricity.

Furthermore, forming conditions in which the applied voltage is increased at an extremely small rate over time cannot be said to be appropriate.

c Means to solve the problem The present invention has been made in view of the above points.

That is, the present invention provides an electron-emitting device in which an electron-emitting section is provided on a substrate to emit electrons by passing a current in the plane of a thin film, in which the electron-emitting section detects the value of the current flowing through the thin film and detects the value of the current flowing through the thin film. The present invention relates to an electron-emitting device characterized in that it is formed by conducting an electrical heating treatment under control of applied voltage.

Furthermore, the present invention provides an electron-emitting device characterized in that, when carrying out current-heating treatment, the value of the current flowing through the thin film is detected, and the voltage applied is controlled based on the detected current value to form an electron-emitting region. This relates to a method of manufacturing an element.

[Example] FIG. 1 is a plan view of an electron-emitting device according to the present invention. In the figure, 1 and 2 are electrodes for performing forming, 3 is a thin film, 4 is a substrate, and 5 is an electron emitting part formed by forming.

The electrodes 1 and 2 are not particularly limited, and a wide range of commonly used electrodes can be used, such as Ni,
Pt, AI! , Cu, Au, and other conductive materials can be used.

The thin film 3 can be made of a wide variety of commonly used materials, such as SnO, -, Inz03. PbO”
A fully bent oxide of J, metals such as Au and Ag, carbon, and various other semiconductors can be used. The thickness of the thin film may be any thickness that is used in ordinary surface conduction layer emitting devices, and a specific example thereof is usually 0.01 to 5 ILm, preferably 0.01 to 5 ILm, although it varies depending on the type of material used. is preferably 0.01 to 0.5 μm.

The substrate 4 can also be a commonly used substrate 1
Quartz, blue plate glass, silicon substrate, etc. are suitable.

Next, the present invention will be specifically explained by showing an example of manufacturing an electron-emitting device according to the present invention.

The shape shown in Fig. 1 (L = 0.3 mm, W = 0
．． A 1mm) Te5no2 film was deposited at a thickness of 100OA(7). Next, using the circuit shown in FIG. 2, the thin film was electrically heated in a vacuum to perform a forming process.

Figure 3 shows the electric power 1 during the forming process in this example.
It is a flowchart showing the procedure of F control. (2) is the voltage applied to the thin film, D is the upstream 1+n flowing through the thin film, Yo is the forming process start voltage, T is the waiting time, and ΔV is the step value of the applied voltage rise. While measuring the current I flowing through the thin film, the applied voltage V is increased at a constant rate, and when ■ decreases, V is fixed and a certain time T is waited.

After waiting for T, the current is measured again, and if it decreases to a certain value, for example, one-half of the current value 0 before waiting for T, the process is terminated. If the current value has not decreased to that extent, V is increased by ΔV again and the same operation is repeated.

Example work Jf In the example (1) above, Vo 410V, ΔV
x30mV.

When the TN was 20 seconds, forming and processing were completed at VZ 20V, and the processing time required for forming at this time was about 5 minutes. When the forming process is performed under these conditions, the variation in device characteristics is the smallest, the variation in emission current is within ±15%, and the time required for forming is the same for each device. The forming process, which used to take a long time, can now be done in a short time and with good controllability.

When the characteristics of the electron-emitting device subjected to the forming treatment in this manner are measured, the emission efficiency defined as the ratio of the emission current to the current flowing in the 11th direction is about 10-3, which is about 10 degrees of the emission efficiency of the conventional device. ~! Great improvement compared to o-6. As for the lifespan, compared to the conventional example where no electron emission occurred after a few minutes to 500 hours of mold emission.
In the element of this example! Electron emission could be stably caused for over 1,000 hours.

In other words, when the electron-emitting device of this example is compared with an electron-emitting device fabricated by the conventional forming method, it is found that the electron-emitting device is improved in terms of electron-emitting efficiency, lifetime, stability of emission current, uniformity of device characteristics, etc. In addition, the time and power consumption required for forming were significantly reduced.

[Effects of the Invention] As explained above, by forming the uninvented electron-emitting device under optimal conditions suited to the device during forming processing, the variation in device characteristics, which was a problem in the past, is reduced and electron-emitting devices are improved. It has excellent characteristics such as efficiency, life, and stability of emission current.

Furthermore, the time required for forming processing can be shortened, and the amount of power consumed for forming can be reduced accordingly.

Furthermore, since forming can be performed under optimal conditions suited to the element, the tolerance for the precision of the shape when forming a thin film increases, making manufacturing easier.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing an example of the electron-emitting device of the present invention, FIG. 2 is a wiring diagram of a circuit for performing forming processing, and FIG. 3 is a voltage control procedure when performing forming processing. FIG. 4 is a plan view showing a conventional electron-emitting device. 1.11... Electrode part, 2.12... Electrode part, 3.13... Thin film, 4,14... Substrate,
5.15...Electron emission part. Figure 1: Ward 2, Ward 4

Claims (2)

[Claims] (1) In an electron-emitting device in which an electron-emitting part is provided on a substrate to emit electrons by passing a current in the plane of a thin film, the electron-emitting part detects the value of the current flowing through the thin film and applies a voltage based on the value of the current flowing through the thin film. 1. An electron-emitting device characterized in that it is formed by conducting electrical heating treatment under the control of: (2) In a method for manufacturing an electron-emitting device in which an electron-emitting part is provided on a substrate to emit electrons by passing an electric current in the plane of the thin film, the value of the current flowing through the thin film is detected when performing energization heat treatment. A method for manufacturing an electron-emitting device, characterized in that an electron-emitting region is formed by controlling an applied voltage based on the voltage and performing an energization process.