JPH0335775B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electron gun that can independently operate a large number of electron sources arranged in a two-dimensional matrix, and can be used, for example, as an electron beam drawing device.

Field emission type electron guns arranged in large numbers in a two-dimensional manner are described in the literature “Physical properties of
thin-film emission cathodes with
molybdenum cones; CASpindt et al., J.
Appl. Phys., Vol 47 No. 12, P5248, 1976. FIG. 1 is a perspective view of the electron gun described here, and FIG. 2 is a sectional view of one of the electron sources. In Figures 1 and 2,
11 is a metal thin plate serving as an anode electrode, 21 is an insulating film,
31 is a cathode electrode, 41 is a conductive substrate, and 50 is a power source. The cathode electrodes 31 are formed into substantially the same needle shape and are arranged on a conductive substrate 41 in a matrix of two rows and two columns, with a total of four electrodes in the illustrated example. The thin metal plate 11 serving as the anode electrode has through holes formed at positions corresponding to the positions of the cathode electrode 31, and is placed on the same conductive substrate 41 with an insulating film 21 in between. The diameter of the through hole drilled in the thin plate of the anode is 1.5 μm, the thickness of the thin plate is 0.4 μm, and the thickness of the insulating film 21 is 1.5 μm. Electrons are emitted from each cathode electrode 31 by applying a voltage of 50 to 100 volts between the conductive substrate 41 that is electrically connected to the cathode electrode 31 and the metal thin plate 11 serving as the anode electrode.

However, with the above configuration, each electron source cannot be operated independently, and it cannot be used for the purpose of obtaining an electron beam image of an arbitrary shape.

An object of the present invention is to take out an electron beam from any electron source out of a large number of electron sources arranged in a two-dimensional matrix and intercept electron beams from other electron sources in the middle, thereby forming an arbitrary shape. An object of the present invention is to provide an electron gun capable of obtaining an electron beam image.

In order to achieve the above object, the features of the present invention are as follows:
Deflection electrodes that deflect the traveling direction of emitted electron beams for each electron beam, and turn on or off the supply voltage to these deflection electrodes (turn on to the ground side)
A group of switches are provided for each electron beam to deflect or not deflect the traveling direction of each electron beam, and a through-hole is provided at a position corresponding to the position of the cathode electrode on the conductive substrate. By adopting a configuration in which the metal thin plate No. 2 is electrically arranged outside the deflection electrode, only the undeflected electron beam is emitted to the outside.

The present invention will be explained below with reference to the drawings.

FIG. 3 is a perspective view showing one embodiment of the present invention, and FIG.
This figure is a sectional view showing the cross section of two of the four electron sources in FIG. 3 and the mutual positional relationship of each component. In the drawings, 31, 32, 33, ... are cathode electrodes made in almost the same needle shape, and in the example, 2×
2 are arranged in a matrix on the conductive substrate 41. Reference numeral 11 denotes a thin metal plate serving as an anode electrode, and has through holes at positions corresponding to the positions of cathode electrodes 31, 32, . . . on the conductive substrate 41. It is placed in an insulated manner. 61, 62, . . . , 65, . . are deflection electrodes for deflecting the traveling direction of emitted electron beams, and two opposing deflection electrodes are provided for each electron beam. Reference numeral 23 is a support for supporting these deflection electrodes. In the illustrated example, 61 and 62 are deflection electrodes for the electron beam from the cathode electrode 31;
and 64 are deflection electrodes for the electron beam from the cathode electrode 32. 50 is a power source for applying voltage between the cathode and anode, 51 and 52 are power sources for applying voltage to the deflection electrodes, and 53 to 56 are connecting the deflection power sources 51 and 52 to each of the deflection electrodes 61 to 64. This is a group of changeover switches arranged in the middle of the connection line to switch the voltage supplied to the deflection electrodes 61 to 64 to the power supply side or to the ground side. Reference numeral 71 indicates a second part provided to block the deflected electron beam and emit only the undeflected electron beam to the outside.
The deflection electrode 61 is mounted on a support base 80 using a thin metal plate.
~ 64, and on the thin plate surface thereof, cathode electrodes 31, 32, . A through hole is provided at each corresponding position.

In order to operate the electron gun of this embodiment having such a configuration, the main body of the electron gun excluding the power supply and changeover switch group is placed in a high vacuum of about 10 ^-9 to ^{10 -10} Torr, and the conductive substrate 41 and A voltage of 50 to 100 V is applied between the first thin metal plate 11 forming the anode electrode. As a result, electrons are emitted from the tips of the cathode electrodes 31, 32, . The beam flows. In FIG. 4, both cathode electrodes 31,
In order to emit the electron beam from 32 to the outside,
All the changeover switch groups 53 to 56 are switched to the ground side (in the figure, the left side of the left and right contacts), and all the deflection electrodes 61 to 64 are grounded. That is, the deflection electrodes 61 to 64 are set to the same ground potential as the first metal thin plate 11 forming the anode electrode. In addition, in order to block the electron beams from both cathode electrodes 31 and 32 with the second thin metal plate 71 and prevent them from being emitted to the outside, all of the four changeover switch groups 53 to 56 are connected to the contacts on the right side of the figure. -Vd volts to deflection electrodes 61, 63, deflection electrodes 62,
Apply a voltage of +Vd volts to 64. moreover,
In order to emit the electron beam from the cathode electrode 31 to the outside and cut off the electron beam from the cathode electrode 32 midway, the changeover switches 53 and 54 are connected to the left contacts and the deflection electrodes 61 and 62 are set to the ground potential, and the changeover switches 53 and 54 are The switches 55 and 56 may be connected to the right contacts to apply the voltage from the deflection power supplies 51 and 52 between the deflection electrodes 63 and 64.

FIG. 5 is a sectional view showing another embodiment of the present invention,
The difference from the embodiment in FIG. 4 is that the deflection electrodes 61 to 64
via the insulating film 22 to form the anode electrode.
The second thin metal plate 71 is supported by a support film 72 and the support film 72 is supported on a support base 80 by a support substrate 73. The configuration and operation are the same as the embodiment shown in FIG.

Next, consider the voltages applied to the deflection electrodes 61 to 64. First metal thin plate 1 forming an anode electrode
1, the acceleration voltage is V _a , the voltage applied to the deflection electrode is V _d , the deflection electrode interval is d , the deflection electrode length is l , from the upper end surface of the deflection electrode to the lower end surface of the second thin metal plate 71 When _the distance is L, the amount of deflection X of the electron beam at the lower _end surface of the second thin metal plate 71 is ) becomes. V _a = 100 volts, l = 3 μm, d = 3 μm,
If L=1000 μm and X=100 μm, V _d will be 20 volts. In this way, each dimension and voltage can be arbitrarily selected and determined by taking into consideration the manufacturing method and the like.

Next, let us consider the through hole formed in the second thin metal plate 71. This through hole has a needle-like cathode electrode 31,
It is necessary that the pitch is the same as 32,...
Moreover, it is also necessary to provide a distance of about 1 mm from the upper end surfaces of the deflection electrodes 61 to 64. Therefore, as shown in FIG. 5, as in the case of an X-ray mask, a support film 72 with through holes formed at positions corresponding to the placement positions of the needle electrodes is placed on a support substrate 73 made of silicon or the like. A thin metal plate 71 having through holes is similarly placed on the surface of the support film 72. thin metal plate 7
1 may be set to the ground potential, or any voltage may be applied thereto. Incidentally, if the metal thin plate 71 has sufficient strength, the structure of the embodiment shown in FIG. 4 can be used without providing the support film 72.

Note that when the electron gun of the present invention is applied to an electron beam exposure apparatus or the like, it is also possible to accelerate the electron beam with an arbitrary acceleration voltage in a subsequent stage of the electron gun.

As explained above, according to the present invention, a deflection electrode and a thin metal plate that blocks or passes the electron beam are provided outside the anode electrode, and the voltage applied to the deflection electrode is controlled. Therefore, electron beams emitted from a large number of electron sources can be selectively extracted to the outside.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a conventional felt-emission type electron gun with a two-dimensional arrangement, FIG. 2 is a sectional view of a part thereof, and FIG. 3 is a perspective view of an embodiment of the present invention.
FIG. 4 is a sectional view of a part thereof, and FIG. 5 is a sectional view showing another embodiment of the present invention. Explanation of symbols, 11... Metal thin plate forming an anode electrode, 21, 22... Insulating film, 23... Support for deflection electrode, 31-34... Cathode electrode, 41... Conductive substrate, 50, 51, 52...Power supply, 53-56
...Switch group, 61-65... Deflection electrode, 71... Second thin metal plate, 72... Support membrane,
73...Support substrate, 80...Support stand.

Claims (1)

[Claims] 1. A large number of cathode electrodes made in approximately the same needle shape are arranged on a conductive substrate, and a thin metal plate with through holes drilled at positions corresponding to the placement positions of these cathode electrodes is used as an anode electrode on the conductive substrate. In an electron gun that is placed electrically insulated from the cathode and anode and emits the electron beam to the outside through each through hole by applying a voltage between the cathode and the anode, the traveling direction of the emitted electron beam is determined for each electron beam. Deflection electrodes are provided to deflect the electron beam, and a switch group is provided to deflect the traveling direction of each electron beam or keep it traveling straight by switching the voltage supplied to these deflection electrodes.
A second thin metal plate having a through hole formed at a position corresponding to the position of the cathode electrode on the conductive substrate is placed outside the deflection electrode in an electrically insulated manner, thereby preventing the deflection from being deflected. An electron gun that emits only an electron beam to the outside.