JPH06105599B2 - Coaxial electrostatic deflector - Google Patents

Description

DETAILED DESCRIPTION [Outline] It is difficult for a parallel plate type electrostatic deflector to match the impedance of a circuit for feeding the electrostatic deflector. Therefore, a coaxial electrostatic deflector is configured to facilitate impedance matching.

[Industrial application field]

The present invention relates to an apparatus using an electron beam, and more particularly to an electrostatic deflector that deflects an electron beam.

In the test of semiconductor integrated circuits, etc., a measuring device has been developed to measure the voltage applied to a conductor by irradiating the conductor with a pulsed electron beam and detecting secondary electrons emitted from the conductor. ing. In order to improve the time resolution of measured values in such an apparatus, it is necessary to use a pulsed electron beam that irradiates the irradiated object for a very short time.

FIG. 4 is a diagram showing a method of forming a pulsed electron beam.

The pulsed electron beam is usually formed by the method shown in FIG. Electron beam 2 emitted from electron beam radiation source 1
Passes through the circular opening 41 formed in the electrostatic deflector 3 and the mask 4, and irradiates the irradiation target 5. The electron beam 2 is deflected by the electrostatic deflector 3 so as to scan the surface of the mask 4 from right to left or from left to right at a high speed,
The electron beam 2 passes through the opening 41 as it crosses the opening 41.
That is, the electron beam 2 is cut into pulses by the mask 4 and irradiates the irradiation target 5.

In such a pulsed electron beam forming method, in order to obtain an electron beam having an extremely short irradiation time, it is necessary to increase the deflection speed of the electron beam 2. However, when the impedance matching between the electrostatic deflector and the circuit for feeding the electrostatic deflector is insufficient, the rising of the potential in the electrostatic deflector is delayed even if the fed potential rises sharply. There's a problem.

Therefore, it is desired to realize an electrostatic deflector having a structure capable of easily matching impedance with a circuit for supplying power to the electrostatic deflector.

[Conventional technology]

 FIG. 5 is a schematic diagram showing a conventional electrostatic deflector.

In the figure, the conventional electrostatic deflector is composed of two flat plates 32 arranged in parallel with a gap 31 interposed therebetween, and a power source 34 is connected to each flat plate 32 through a cable 33. The electron beam 2 is configured to pass through the gap 31,
The voltage is deflected in accordance with the potential difference, the polarity, etc. of the voltage applied to the two flat plates 32 while passing through.

[Problems to be solved by the invention]

However, the conventional parallel plate type electrostatic deflector has a problem that it is extremely difficult to match the impedance of the two plates with the impedance of the cable or the power source.

[Means for solving problems]

FIG. 1 is a principle view showing a coaxial electrostatic deflector according to the present invention. Note that the same object is denoted by the same symbol throughout the drawings.

The above problem is composed of a tubular conductor 61 and a rod-shaped conductor 62 provided inside the tubular conductor 61, and an electron beam can be incident between the tubular conductor 61 and the rod-shaped conductor 62. This is solved by the coaxial electrostatic deflector of the present invention in which a beam passage hole 63 penetrating the cylindrical conductor 61 is provided at the position.

[Action]

In FIG. 1, a voltage is applied between the cylindrical conductor 61 and the rod-shaped conductor 62, and the electron beam 2 entering from the incident side of the beam passage hole 63 provided in the side wall of the cylindrical conductor is The light is deflected while passing through the gap between the rod-shaped conductor 61 and the rod-shaped conductor 62 and exits from the exit side of the beam passage hole 63. The impedance of the coaxial electrostatic deflector composed of the cylindrical conductor and the rod-shaped conductor is determined by the ratio of the inner diameter D of the cylindrical conductor and the outer diameter d of the rod-shaped conductor, and if the impedance of the cable or the power supply is determined. , An electrostatic deflector matched to the impedance can be easily obtained.

〔Example〕

An embodiment of the present invention will be described below with reference to the accompanying drawings. FIG. 2 is a sectional perspective view showing an embodiment of the present invention, and FIG. 3 is a side sectional view showing a modification of the present invention.

In FIG. 2, the electrostatic deflector according to the present invention comprises a deflecting section 6, connector connecting sections 7 provided at both ends, and a coupling section 8 provided between the deflecting section 6 and the connector connecting section 7. There is. The deflecting section 6 is composed of a cylindrical conductor 61 and a rod-shaped conductor 62 having a circular cross section, and a beam passage hole 63 penetrating in a direction perpendicular to the axial direction of the cylindrical conductor 61 has a cylindrical conductor. 61
Is provided on the side wall. The connector connecting portion 7 is also composed of a cylindrical conductor 71 and a rod-shaped conductor 72, and has a structure in which a connector mounted on a cable (not shown) can be mounted.

When the electron beam is deflected by such an electrostatic deflector, a larger deflection angle can be obtained as the distance from the incident side to the emitting side of the beam passage hole 63 increases. Therefore, in the illustrated electrostatic deflector, it is more advantageous that the cylindrical conductor 61 and the rod-shaped conductor 62 have a larger diameter. On the other hand, the shape of the connector connecting portion 7 is limited by the connector connected thereto.

Therefore, as shown in the figure, in the deflecting portion 6, the diameters of the cylindrical conductor 61 and the rod-shaped conductor 62 are increased, and the connector connecting portion 7 is connected by the connecting portion 8 including the outer conductor 81 and the inner conductor 82. There is. The cylindrical conductors 61, 71 and the external conductor 81
Are formed from the same cylindrical conductor, and the rod-shaped conductors 62 and 72 and the internal conductor 82 are formed from the same rod-shaped conductor.
Each of them may be formed of a separate conductor and joined so that electrical continuity can be obtained.

The impedance of the coaxial electrostatic deflector including the tubular conductor and the rod-shaped conductor is determined by the ratio of the inner diameter D of the tubular conductor and the outer diameter d of the rod-shaped conductor. Therefore, the inner diameter of the cylindrical conductor 61 and the diameter of the rod-shaped conductor 62 in the deflection portion 6, and the inner diameter of the cylindrical conductor 71 and the rod-shaped conductor 72 in the connector connection portion 7
By selecting the ratio of the diameters of the cylindrical conductors 61 and the inner surface of the cylindrical conductor 61 and the inner surface of the cylindrical conductor 71, and the surface of the rod-shaped conductor 62 and the surface of the rod-shaped conductor 72 in the joint portion 8, ,
An electrostatic deflector that matches the impedance of the cable or the power supply can be easily obtained.

Further, in the modification of the present invention shown in FIG. 3, the deflecting portion 6 is composed of a cylindrical conductor 61 and a rod-shaped conductor 62 having a rectangular cross section, and is perpendicular to the axial direction of the cylindrical conductor 61. A beam passage hole 63 is provided in the direction. Even in such a coaxial electrostatic deflector, by appropriately selecting the ratio of the inner dimension of the cylindrical conductor 61 and the dimension of the side of the rod-shaped conductor 62, the electrostatic deflection matched to the impedance of the cable or the power supply is obtained. Can be easily obtained.

〔The invention's effect〕

As described above, according to the present invention, it is possible to provide an electrostatic deflector having a structure for easily matching the impedance with a circuit for supplying power to the electrostatic deflector.

[Brief description of drawings]

 FIG. 1 is a principle view showing a coaxial electrostatic deflector according to the present invention, FIG. 2 is a sectional perspective view showing an embodiment of the present invention, and FIG. 3 is a side sectional view showing a modified example of the present invention. FIG. 4 is a diagram showing a method of forming a pulsed electron beam, and FIG. 5 is a schematic diagram showing a conventional electrostatic deflector. In the figure, 2 is an electron beam, 6 is a deflecting portion, 7 is a connector connecting portion, 8 is a connecting portion, 61 and 71 are cylindrical conductors, 62 and 72 are rod-shaped conductors, 63 is a beam passage hole, and 81 is an external conductor. A body and 82 are internal conductors, respectively.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kazuo Okubo 1015 Kamiodanaka, Nakahara-ku, Kawasaki City, Kanagawa Prefecture, Fujitsu Limited (72) Inventor Toshihiro Ishizuka 1015, Kamikodanaka, Nakahara-ku, Kawasaki City, Kanagawa Prefecture, Fujitsu Limited (56) References JP-A-62-119845 (JP, A)

Claims (1)

[Claims] 1. A tubular conductor (61) and a rod-shaped conductor (62) provided inside the tubular conductor (61), and the tubular conductor (61) and the rod-shaped conductor. A coaxial electrostatic deflector comprising a beam passage hole (63) penetrating the tubular conductor (61) at a position where an electron beam can enter the conductor (62).