JPS6091528A - Field emitter consisting of transition metal compound - Google Patents

Abstract

PURPOSE:To obtain an emitter with stable high brightness by introducing nitrogen and/or oxygen into a carbon cavity of a transition metal carbide for being subjected to solid resolution. CONSTITUTION:The axial azimuth of a field emitter consisting of a transition metal compound, in which a chemical composition of the material is to be shown by a general formula MCXNYOZ (In the formula, M denotes a solid solution onsisting of a single or not less than two kinds of the transition metals of the families IV a, V a and VI a, 0.5<=x+y+z<=1, 0.5<=x<=1, 0<=y<=0.5, 0<=z<=0.5) is made <110> + or -10 deg., while the direction of a radiant electron beam is made into the emitter axial azimuth. Thereby, the pattern center part is extremely bright thus being able to obtain the field emitter having the stable radiant properties.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a field emitter used in electron beam exposure machines, high-intensity electron beam utilization equipment, and the like.

The emission current from the field emitter has high brightness, the energy width of the emitted electrons is small (1), and it has excellent features such as being close to a point light source.

Conventionally, tungsten has been put into practical use as a field emitter material, but transition metal carbides have a smaller work function than tungsten and are inert to reactions with residual gas, so they are expected to be used as electron emitting materials. has been done. In the transition metal carbide MCX (where M represents a transition metal), the present inventors researched a method for reducing carbon vacancies, and found that nitrogen and/or By introducing oxygen into a solid solution, we succeeded in obtaining a high-luminance field emitter that was reduced and more stable than K.

This chemical composition has the general formula MCxNy02 (Tatashi・M
Ha II/a・Va, Va group transition metal single (2); ゛Katsura or solid solution of two or more types, 0.5 <, x +
It is a transition metal compound represented by y+z<1.0.5, 0.5, and z<0.5.

A specific example of the transition metal is Ti5Zr.

If, V, Nb XTa-Mo%W and solid solutions thereof.

However, for (001) and (111) emitters, the emission pattern (illf
fl(a) shows (001), and FIG. 2 shows (111).

) is not desirable.

The present invention seeks to provide a field emitter in which the center of the pattern is bright.

As a result of research to achieve this objective, the present inventors have found that in order to emit an electron beam in the emitter axis direction and brighten the center of the emission pattern, an emission pattern as shown in Figure 1 (C) is required. It turns out that it is better to use a (110) emitter.

That is, from research on the surface of single crystals of carbides (for example, Tie), it has been found that in carbides, the (001) and (111) planes have low surface energy and are stable planes that easily develop.
When a chip with a tip diameter of 0.1 μm is heated at a high temperature, (001) and (111) planes develop at the tip and are surrounded by these planes. It was found that electron emission occurred from a local area (a point where the ridge lines were gathered) where the electric field intensity was large as shown in Fig. 2(a).

The same is true for <111> emitters.

Therefore, it can be seen that in order to extract the emission current in the direction of the emitter axis (directly below), the design should be designed so that a strong electric field strength is obtained at the leading edge of the chip, as shown in Figure 2 (b). .

i; C11; In order to obtain a strong electric field strength at the leading edge of such a chip, (110
) It turns out that this can be realized and obtained only with chips.

As shown in the emission pattern ij of the field emitter using the <110> chip: No. 111(c), an electron beam is emitted at the center and four bright spots are formed around it.

The present invention was completed based on these findings.

The gist of the present invention is to provide a field emitter made of a transition metal compound, characterized in that the chemical composition of the material is such that the axial orientation of the general formula Mitter is (110) ±10°, and the direction of the emitted electron beam is the emitter axial orientation. It is in.

The axial direction of the field emitter in the present invention (5) It is most preferable to have E45 in the (110) direction, but since the electron beam emitted directly below has a certain width, it is the same within a range of ±10°. Effects can be obtained. However, if you deviate from this, you will not be able to achieve your purpose.

Example T1Co, 96No. . 20 o. 3〈110〉 Emission pattern from field emitter h M
1 tffl(c) is υ, and the current noise is also 0.2
% or less, current fluctuations at 1000°C, vacuum level 8 x 1
According to the field emitter of the present invention, the center of the pattern is extremely bright, as shown by 0 Torr, applied voltage of 1980 V, and emission current of 1 μ80 or more, and also has a transition state in which N1 and (-! or) 0 are dissolved in solid solution. Since metal carbide is used as the emitter material, current noise is also 0.
2% or less, current fluctuation is -0.04%/Ihr.

It has the effect of having the following stable radiation characteristics.

[Brief explanation of drawings]

FIG. 1 shows an emission pattern diagram from the MCxNyOz field emitter. The X mark indicates the center position. Fig. 1(a) shows the emission pattern of MCXNyo2<001>, Fig. 1(b) shows the emission pattern of MCxNyO□<111>, and Fig. 1(c) shows the emission pattern of MOxNyO2<110> Fig. 2(a). is (001) the tip shape of the tip, the second
(Figures) show the tip shape of the (110) tip. (7) Tea 1 Zuen Shi No. 2 139-

Claims (1)

[Claims] 1 The chemical composition of the material is expressed by the general formula MOxNyO, (where M
is N, V, solid solution of Va group transition metals alone or two or more, 0.5x+y+z<1, 0.5<:x1, y<o, s, O< The field emitter is made of a transition metal compound represented by 1<110>±10°, and the direction of the emitted electron beam is the emitter axis. A field emitter made of transition metal compounds.