JP2562168Y2 - Field emission device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a field emission device (hereinafter, also referred to as FEC). The field emission device of the present invention is useful as an electron source in various display devices, micro vacuum tubes, light sources, amplification devices, high-speed switching devices, sensors, and the like.

[Conventional technology]

FIG. 8 is a so-called planar type (planar type) structure diagram which is an example of the structure of the field emission device.

On an insulating substrate 200, an emitter 202 having a protruding end 201 at the center is provided. Adjacent to the emitter 202, a pair of gates 204, 204 each having an opening 203 at a portion corresponding to the protruding end 201, are provided. here,
The tip 201 of the emitter 202 is at a certain distance from the line connecting the two gates 204,204. That is, the tip 201
Is not located in the opening 203. A collector 205 is provided in parallel with the gate 204 on the substrate 200 opposite to the emitter 202 with the gate 204 therebetween.

Here, between the emitter 202 and the gate 204 and the gate 20
When a predetermined potential difference is applied between 4 and the collector 205, electrons emitted from the tip 201 of the emitter 202 reach the collector 205 via the opening 203 of the gate 204.

[Problems to be solved by the invention]

In order to obtain sufficient electron emission in the flat field emission device, the electric field intensity at the tip of the emitter must be increased. For that purpose, it was necessary to increase the voltage applied to the gate electrode.

However, when the gate voltage is increased to a certain value or more, there is a problem that gas discharge occurs due to discharge or local heating of the gate, and the tip of the emitter is damaged.

Also, since high-voltage driving elements such as high-voltage transistors are expensive, in order to reduce the price of the product and obtain sufficient electron emission, an effective electric field is applied only to the tip of the emitter while lowering the gate voltage. However, the conventional field emission device did not satisfy such a condition.

[Means for solving the problem]

The field emission device of the present invention is provided in close contact with the surface of the substrate in parallel with the surface of the substrate, and has a plate-like emitter having a plurality of tips whose tips are substantially linearly arranged; A plurality of recesses are provided in close contact with the surface of the substrate in parallel with the surface and surround both sides and the front of each of the tips of the emitter. The direction in which the tips are arranged while increasing the electric field strength at the tip of the emitter And a plate-like gate for generating a potential distribution substantially parallel to the front of the emitter.

[Action]

When the tip of the emitter is surrounded by the gate,
If the other conditions are the same, the intensity of the electric field generated at the tip of the emitter is larger than in the case where the emitter is not enclosed. Further, a potential distribution substantially parallel to the direction in which the tips are arranged is generated in front of the emitter. Therefore, the amount of electrons emitted from the emitter increases, and this can be efficiently sent to the front of the emitter.

〔Example〕

An embodiment of the present invention will be described with reference to FIGS.

 1 to 7 show a planar type field emission device.

The field emission device 30 shown in FIG. 1 has an emitter 32 and a gate 33 having substantially the same thickness arranged on a substrate 31 side by side.
At one edge of the rectangular emitter 32, a triangular tip portion 34 is provided. A recess 35 is provided at one edge of the gate 33 corresponding to the tip 34, and surrounds the tip 34 of the emitter 32.

According to such a configuration, the electric field strength at the distal end portion 34 of the emitter 32 can be increased as compared with the conventional planar type field emission device even under the same driving conditions. That is, without increasing the voltage applied to the gate 33, the electric field strength at the tip portion 34 of the emitter 32 can be increased to increase the amount of emitted electrons.

FIG. 2 shows another embodiment of the planar type field emission device. Like the field emission device 40, the tip of the emitter 32
Even if the recess 42 of the gate 41 surrounding the gate 34 is rectangular, the same operation and effect as the embodiment of FIG. 1 can be obtained.

FIG. 3 shows a planar type field emission device 50 according to another embodiment. As described above, the tip 52 of the emitter 51 may be surrounded by the U-shaped gate.

FIG. 4 shows another embodiment of the planar type. In this field emission device 60, the pattern of the emitter and the gate body is almost the same as that of FIG.
It is thinner, and a columnar pin 64 is erected so as to surround the recess 63 of the gate 61. As described above, even when the distal end portion 65 of the emitter 62 is surrounded by the concave portion 63 of the gate 61 and the pin 64, the same operation and effect as those of the above-mentioned respective embodiments of the planar type can be obtained.

FIG. 5 shows another embodiment of the planar type. In the field emission device 70, a trapezoidal concave portion 72 is provided in a gate 71 thinner than the emitter 62, and a pair of cylindrical pins 73 are provided upright on both sides of each concave portion 72. According to this embodiment, the same operation and effect as the embodiment of FIG. 4 can be obtained.

FIG. 6 shows another embodiment of the planar type. The structure of the emitter 62 of the field emission device 80 is the same as that of each of the above-mentioned planar type embodiments. The gate 81 provided on the substrate 31 alongside the emitter 62 is thinner than the emitter 62, and the gate 81 has a gate member 82 surrounding each tip 65 of the emitter 62.
Are provided at predetermined intervals. According to this embodiment, the same operation and effect as those of the above-described planar embodiments can be obtained. In the figure, reference numeral 83 denotes a collector.

FIG. 7A shows a rectangular gate 3 having an opening 301.
13 shows a conventional planar-type field emission device 300 composed of a semiconductor device 02 and an emitter 303, and an electric field analysis result thereof. FIG. 1B shows a field emission device according to a planar type embodiment.
90 shows the result of the electric field analysis. The gate 91 in the embodiment of FIG. 7B is a substantially T-shaped gate obtained by adding a rectangular projection 93 toward the emitter 92 to the gate 302 of FIG. Tip 94
And the distance between the gate 91 and the conventional example are not different.

According to the present embodiment, the tip 94 of the emitter 92 is connected to the gate 91.
, The electric field strength at the tip 94 of the emitter 92 is about 10 times lower than that of the conventional example, as can be seen from the comparison of the figures.
% Has increased. Therefore, when it is difficult to reduce the shortest distance between the tip of the emitter and the gate in manufacturing the field emission device, the structure of this embodiment is effective to obtain sufficient electron emission at a low gate voltage. .

[Effect of the invention]

In the planar field emission device of the present invention, since both sides and the front of the tip of the emitter are surrounded by the concave portion of the gate, a potential distribution substantially parallel to the direction in which the tips are arranged occurs in front of the emitter, The electric field strength at the tip increases.
Therefore, while reducing the gate voltage, an effective electric field is generated only at the tip of the emitter to obtain sufficient electron emission, which can be efficiently sent toward the front of the emitter.

[Brief description of the drawings]

1 and 2 are perspective views showing an embodiment of a planar type field emission device according to the present invention, respectively. FIG. 3 is an enlarged view of a main part of the planar type embodiment, and FIGS. FIGS. 6 and 7 are perspective views showing an embodiment of the planar type field emission device according to the present invention, respectively. FIG. 7 (a) is a diagram showing a conventional planar type field emission device and its electric field analysis result. FIG. 7B is a diagram showing a planar type field emission device of the embodiment and the results of an electric field analysis thereof, and FIG. 8 is a perspective view of a conventional planar type field emission device. 30,40,50,60,70,80,90 …… Field emission device 33,41,53,61,71,81,91 …… Gate 32,51,62,92 …… Emitter 34,52,65, 94 ... Tip

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-4-126332 (JP, A) JP-A-3-295130 (JP, A) JP-A-4-28138 (JP, A) JP-A-3-28130 190034 (JP, A) JP-A-1-154426 (JP, A) JP-A-63-274048 (JP, A) US Pat.

Claims (1)

(57) [Scope of request for utility model registration] A plate-shaped emitter provided in close contact with the surface of the substrate in parallel with the surface of the substrate and having a plurality of tips whose tips are aligned substantially in a straight line; A plurality of recesses that are provided in close contact with the surface of the substrate and surround both sides and the front of each tip of the emitter, to increase the electric field strength at the tip of the emitter and to substantially extend in the direction in which the tips are lined up. A plate-shaped gate for generating a potential distribution parallel to the emitter in front of the emitter.