JPS6369133A - Electron emission device - Google Patents

Abstract

PURPOSE:To enable many electron emission elements to be easily controlled with high precision, by changing driving voltages applied to the electron emission elements whenever pulses of input pulse signals are inputted by a driving means. CONSTITUTION:When a pulse signal phi is inputted to an input terminal T in a logic circuit 13, the output terminal Q is inverted to be on a high level and on a low level alternately whenever the pulses are inputted. When the output terminal Q is on the high level, an electronic switch 12 is turned ON, so that a current flows across a resistance R and a voltage approximately equal to a voltage V2 is applied to an acceleration electrode 11. When the voltage much higher than that on the electrode (a) is applied to the acceleration electrode 11 in this way, electrons are accelerated and emitted from an electron emission port of an electron emission element 10. On the contrary, when the output terminal Q is on the low level, the electronic switch is turned OFF, so that the acceleration electrode 11 becomes equipotential with the electrode (a) and the electron emission is suppressed. Therefore, the electron emission can be performed at desirable timing or for a desirable time only by properly setting periods and phases of the input signal phi.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an electron-emitting device having an electron-emitting element having an accelerating electrode and driving means for the electron-emitting element.

[Prior art 1] Electron-emitting elements used in conventional electron-emitting devices include those that use avalanche breakdown of a PM junction, those that apply a forward bias to a ρN junction and inject electrons into the P layer, and those that use a thin insulator. CMIX type), which has a structure in which layers are sandwiched between metals.
In addition, field emission type and surface conduction type elements have been proposed.

FIG. 6(A) shows that the PM junction is forward biased and
6 is a schematic explanatory diagram of an electron-emitting device of a type in which electrons are injected into a layer, and FIG. 6(B) is a graph showing a schematic current-voltage characteristic thereof.

In the same figure (A), when a forward bias voltage V is applied to the PM junction, the forward direction current I as shown in the same figure (B)
flows, and electrons injected from the N layer to the P layer are emitted from the surface of the p layer into vacuum. The surface of this P layer is coated with cesium Cs or the like in order to lower the work function and increase the amount of electron emission.

Fig. 7 I) Schematic configuration diagram of type I electron-emitting device, Fig. 8
The figure is a schematic diagram of a surface conduction electron-emitting device.

HIM-type electron-emitting device has a structure in which a metal electrode 1, an insulating layer 2, and a thin metal electrode 3 are stacked, and by applying a voltage between the electrodes 1 and 3, electrons are emitted from the thin electrode 3 side.

Further, in the surface conduction type electron-emitting device, electrodes 5 and 6 are formed on an insulating substrate 4, and a rough high-resistance thin film 7 is formed between them. Then, by applying a voltage between the electrodes 5 and 6, electrons are emitted from the surface of the high-resistance thin film 7.

[Problems to be Solved by the Invention] In an electron-emitting device using such an electron-emitting device, electron emission is controlled, especially ON/OFF, by a driving voltage applied to the electron-emitting device or an accelerating voltage applied to the accelerating electrode.
can be controlled.

However, in the conventional electron-emitting device, electron emission was only controlled by a variable voltage power supply, and therefore it was not possible to drive a particularly large number of electron-emitting elements with ease and precision.

Furthermore, when driving a large number of electron-emitting devices, a large number of variable voltage power supplies must be used, which has the problem of increasing the size and complexity of the device.

[Means for Solving the Problems] An object of the present invention is to solve the above-mentioned conventional problems, and to provide an electron-emitting device that can easily and accurately control a large number of electron-emitting devices even when they are arranged. The goal is to provide equipment.

An electron-emitting device according to the present invention includes an electron-emitting element having an accelerating electrode and a driving means for the electron-emitting element, wherein the driving means accelerates the acceleration every time a pulse of an input pulse signal is input. The method is characterized in that the emission of electrons is controlled by changing the voltage applied to the electrodes or the driving voltage applied to the electron-emitting device.

[Operation] Since electron emission can be controlled only by pulse input in this way, control becomes easy, and even if a large number of electron-emitting devices are arranged, electrons can be easily emitted in a desired manner (for example, by scanning). be able to.

Further, in order to change the electron emission every time a pulse of the input pulse signal is input, the timing and time of electron emission can be arbitrarily set by changing the cycle and phase of the pulse signal.

[Example] Hereinafter, an example of the present invention will be described in detail based on the drawings.

FIG. 1 is a schematic diagram of a first embodiment of an electron-emitting device according to the present invention.

In the figure, an accelerating electrode 11 is provided at the electron emission port of the electron emission device 10, and a driving voltage v1 is applied between the electrode a on the electron emission port side of the electron emission device 10 and the electrode on the opposite side. .

Further, a voltage across the resistor R is applied to the electrode a and the accelerating electrode 11 so that the accelerating electrode 11 has a high potential.

That is, the accelerating voltage V2 is applied to the resistor R via the electronic switch 12, the high potential side terminal of the resistor R is connected to the accelerating electrode 11 together with one terminal of the electronic switch 12, and the low potential side terminal of the resistor R is connected to the accelerating electrode 11 together with one terminal of the electronic switch 12. A terminal is connected to electrode a.

However, the resistance R needs to be sufficiently smaller than the effective resistance value between the electrode a and the accelerating electrode 11.

Further, a control terminal of the electronic switch 12 is connected to an output terminal Q of the logic circuit 13. The logic circuit 13 inverts the level of the output terminal Q according to the pulse signal φ input to its input terminal, and turns the electronic switch 12 ON/OFF.
control.

FIG. 2 is a timing chart for explaining the operation of this embodiment.

As shown in the figure, when the pulse signal φ is input to the input terminal T of the logic circuit 13, the high level and low level from the output terminal Q are inverted for each input pulse.

When the output terminal Q is at a high level, the electronic switch 12 is set to O.
The N state is entered, and as a result, a current flows through the resistor R, and a voltage approximately equal to the voltage v2 is applied to the accelerating electrode 11. When a sufficiently higher voltage than the electrode a is applied to the accelerating electrode 11 in this manner, electrons are accelerated and emitted from the electron emitting port of the electron emitting element 10.

Conversely, when output terminal Q is at low level, electronic switch 1
2 is in an OFF state, the accelerating electrode 11 has the same potential as the electrode a, and the emission of electrons is suppressed.

Therefore, electron emission can be performed at a desired timing or for a desired period of time simply by appropriately setting the period and phase of the input pulse signal φ.

In this way, since the electron-emitting devices can be controlled using only the pulse signal φ, even when a large number of electron-emitting devices 10 are arranged, the control can be performed easily.

FIG. 3 is a schematic diagram of a second embodiment of the present invention.

In this embodiment, the electronic switch 12 turns on/off the drive voltage v1 to control electron emission. Even with this embodiment, the same effects as in the above embodiment can be obtained.

Although each embodiment shows an example in which a transistor is used as the electronic switch 12, the present invention is not limited to this, of course, and better switch characteristics can be obtained if an analog switch is used.

Further, the logic circuit 13 may be of any type having the above-mentioned n-channels, but a T-type flip-flop circuit is generally used.

Further, the electron-emitting device 10 in each embodiment can be any of the various electron-emitting devices already described.
- An avalanche type is shown as an example.

FIG. 4 is a schematic cross-sectional view of an avalanche breakdown type electron-emitting device having a PM wave junction.

In the figure, a P middle layer 102 is formed on a P type semiconductor substrate 101, and a thin N middle layer 103 is formed thereon. Furthermore,
After laminating the insulating layer 103 and the metal layer for the accelerating electrode 105, the insulating layer and the metal layer corresponding to the P intermediate layer 102 are removed to form the electron emission aperture 10B. Finally, by forming an electrode 107 on the opposite side of the substrate 101, an avalanche breakdown type electron-emitting device having a PM wave junction is formed. In addition, in correspondence with FIGS. 1 and 3, electrode a is the electrode connected to the N+10 layer 03, and the electrode 10? Also, the accelerating electrode 11 is the accelerating electrode 105
When a reverse bias voltage v1 is applied to the electrodes a and b of such an electron-emitting device, the heavily doped P intermediate layer 1
Avalanche breakdown occurs in the depletion region between the N layer 103 and the N layer 103, and accelerated electrons are emitted from the surface of the N layer 103. Since the electrons are accelerated from the P+ layer 02 to the N layer 103 side in the depletion region, the energy distribution of the emitted electrons is sharp and the emission efficiency is high.

Further, since the voltage v2 is applied to the accelerating electrode 105, the emitted electrons are accelerated and the work function is reduced due to the Schottky effect, so that the electron emission efficiency can be increased.

Note that the electron-emitting device 10 is, of course, not limited to the above-mentioned avalanche breakdown type, but may be of the PN type as already described.
type, MIM type, etc. can be used.

FIG. 5 is a schematic diagram of a third embodiment of the present invention.

In the figure, a plurality of PN type electron-emitting devices 10 and accelerating electrodes 11 are arranged, each of which constitutes the circuit shown in FIG.

In such a multi-device, the pulse signal φ
1, φ2 and Φ. are respectively input to the logic circuit 13 at a desired timing, and electrons can be emitted from a large number of electron-emitting devices 10 in a desired pattern.

[Effects of the Invention] As explained in detail above, the electron emitting device according to the present invention can control electron emission only by pulse input, so that control is easy, and even when a large number of electron emitting elements are arranged, Electrons can be easily emitted (eg, scanned) in a desired manner.

Further, in order to change the electron emission every time a pulse of the input pulse signal is input, the timing and time of electron emission can be arbitrarily set by changing the cycle and phase of the pulse signal.

Therefore, when performing electron beam drawing on a semiconductor wafer, for example, a desired pattern can be drawn by simply arranging a plurality of electron-emitting devices and applying desired pulse signals to each of them.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram of a first embodiment of a bubble discharge device according to the present invention, FIG. 2 is a timing chart for explaining the operation of this embodiment, and FIG. 3 is a diagram of a first embodiment of the invention. 4 is a schematic cross-sectional view of an avalanche breakdown type electron-emitting device having a PM junction; FIG. 5 is a schematic configuration diagram of a third embodiment of the present invention; Figure 6 (A) is a schematic explanatory diagram of an electron-emitting device that injects electrons into two layers by applying a forward bias to the PN junction, and Figure 6 (B) is a schematic illustration of its current flow. - Graph showing voltage characteristics; FIG. 7 is a schematic diagram of a HIM type electron-emitting device; FIG. 8 is a schematic diagram of a surface conduction type electron-emitting device. 10...Electron-emitting devices 11, 105...Accelerating electrode 12...Electronic switch 13...Logic circuit agent Patent attorney Minoru Yamashita Hirabe 1st 2nd time Release 6-L''-7 ” - 3rd 4th Ti4

Claims (2)

[Claims] (1) In an electron-emitting device having an electron-emitting element having an accelerating electrode and a driving means for the electron-emitting element, the driving means applies a voltage to the accelerating electrode every time a pulse of an input pulse signal is input. Alternatively, an electron emitting device characterized in that emission of electrons is controlled by changing a driving voltage applied to the electron emitting device. (2) The driving means includes logic means that changes the output level each time a pulse of the pulse signal is input, and applies a voltage to the accelerating electrode or the electron-emitting device according to the output level of the logic means. 2. The electron-emitting device according to claim 1, further comprising power supply means for changing a drive voltage.