JPH033318A - Electron beam exposure device - Google Patents

Abstract

PURPOSE:To avoid any needless exposure during blanking process by a method wherein the title electron beam exposure device is provided with a controller controlling the current to an electron lens system so that, during the blanking process, the electron arrested level by an electron arresting case may be raised as high as possible. CONSTITUTION:The title electron beam exposure device wherein the electron beam emitted from an electron beam emitter 2 is focussed by use of electron lens systems 3, 5 to be emitted to the surface of a work 7 while during the interrupting time of the exposure by the use of the electron beam, the electron beam is deflected to an electron arresting case 8 by a blanking deflector 4 is provided with a controller 10 controlling the current to the electron lens system 3 so that the electron arrested level by the electron arresting case 8 during the interrupting time of the exposure may be raised as high as possible. For example, the electron arresting case 8 is provided with a detecting wire with a resistor R inserted thereinto to be grounded and connected to the controller 10. Furthermore, during the blanking process, the current values I A, B, C to the irradiating lens system 3 are controlled to maximize the voltage values VR at both terminals of the resistor R.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electron beam exposure apparatus that uses an electron beam to perform exposure processing on a resist or the like on the surface of a workpiece.

[Conventional technology]

FIG. 3 is a schematic diagram of a conventional electron beam exposure apparatus disclosed in, for example, Japanese Unexamined Patent Publication No. 56-18425.
2 shows a housing, and 2 shows an electron gun disposed at the upper part inside the housing l. In the housing 1, below the electron gun 2, an irradiation lens system 3, a blanking deflection system 4, an objective lens system 5, and a scanning deflection system 6 are arranged in this order with a required interval between them. Furthermore, a sample 7, which is an object to be processed, is arranged below the scanning deflection system 6. An electron collection housing 8 is installed between the blanking deflection system 4 and the objective lens system 5, facing to the side of the center line connecting the electron gun 2 and the sample 7.

The electron collection housing 8 is formed in a hollow rectangular shape, and the electron gun 2
A small hole 8a is opened in the side surface so that the electron beams E, E, which are deflected during blanking, are taken into the electron collection housing 8 through the small hole 8a.

Reference numeral 10 denotes a control unit, which controls the scanning deflection system 6 during drawing to draw on the surface of the sample 7 with the electron beam E0, and controls the planking deflection system 4 during blanking to capture the electron beam. The light is deflected into the collecting casing 8 and placed on standby to prevent unnecessary exposure.

In such a conventional apparatus, the electron beam E0 emitted from the electron gun 2 and focused on the sample 7 by the irradiation lens system 3 and the objective lens system 5 is controlled based on the pattern position signal from the control section 10. It is moved over the sample 7 by the deflection force of the controlled scanning deflection system 6 to draw a pattern. When the pattern is drawn, the control unit 1 uses the blanking deflection system 4 to temporarily interrupt the drawing until the next pattern is drawn.
0 command signal, a deflection force is applied to the electron beam E0 to greatly deviate it from the optical axis, and the deflected electron beam E,...
E is made to enter the electron collection housing 8 through the small hole 8a and is collected.

[Problem to be solved by the invention]

By the way, in such a conventional electron exposure apparatus, the current distribution of the electron beam E0 is a Gaussian distribution with a long tail, so even if blanking is performed by the blanking deflection system 4, all of the current is transferred to the electron collection housing 8. There is a problem in that the electron beams cannot be collected internally, and a portion of the electron beams leaks and exposes resists and the like on the workpiece, resulting in unnecessary exposure.

The present invention has been made in view of the above circumstances, and an object thereof is to provide an electron beam exposure apparatus that does not cause unnecessary exposure even during blanking.

[Means to solve the problem]

The electron beam exposure apparatus according to the present invention includes a control section that performs current control on the electron lens system so that the electron collection housing becomes as large as possible during blanking.

[Effect]

According to the present invention, the focusing position of the electron beam by the electron lens system during blanking is thereby positioned at a position where the amount of electrons collected by the electron collection housing is large.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below based on drawings showing embodiments thereof.

FIG. 1 is a schematic vertical sectional view of an electron beam exposure apparatus according to the present invention (hereinafter referred to as the present invention apparatus), in which 1 indicates a housing and 2 indicates an electron gun disposed at the upper part of the housing 1. There is.

Below the electron gun 2 is an irradiation lens system 3. Blanking deflection system 4. Objective lens system5. The scanning deflection systems 6 are arranged in this order on a substantially straight line at a required distance from each other, and the sample 7 is arranged below the scanning deflection systems 6, and the irradiation lens system 3 and the objective lens Electron gun 2 and sample 7 are located between system 4 and
An electron collection housing 8 is installed on the side of the center line connecting the two. The electron collection housing 8 is formed in the shape of a hollow rectangular parallelepiped, and has a small hole 8a opened on the side facing the electron gun 2, so that the electron beam is taken into the inside through the small hole 8a during blanking. It has become. A detection line that is grounded through a resistor R is provided in the electron collection casing 8, and this is connected to the control unit 1.
0, and as the electron collection casing becomes larger, the voltage value across the resistor R increases, and conversely, as the electron collection casing becomes smaller, the voltage value decreases.

The control unit 10 controls the power supply to the irradiation lens system 3, the blanking deflection system 4, the scanning deflection system 6, etc., and samples the voltage value of the detection line attached to the electron collection housing 8. There is.

FIG. 2(a) is an explanatory diagram showing the relationship between the current to the irradiation lens system 3 and the focal point O of the electron beam, and as the current to the irradiation lens system 3 is reduced, the focal point of the electron beam changes to A, As shown in B and C, the distance from the irradiation lens system 3 is shown in Fig. 2 (Ro). ) as shown below.

Figure 2 (b) is a graph showing the relationship between the voltage value across the resistor 8 and the current value to the irradiation lens system 3, with the horizontal axis representing the current value to the irradiation lens system and the vertical axis representing the voltage value. This is an indication.

As is clear from this graph, when the convergence point of the electron beam is set to point B, that is, when the current value to the irradiation lens system 3 is I, the maximum voltage (negative) is shown, and the current value to the irradiation lens system 3 is Ig. It can be seen that as the current value becomes larger or smaller, the current value decreases, in other words, the amount of electron beam collection decreases. Therefore, if the current value I to the irradiation lens system 3 is controlled so that the electron collection case is maximized during blanking, in other words, the voltage value across the resistor 8 is maximized, the amount of leaked electrons can be reduced accordingly. Become.

Note that the range of current control may be within the range of the current value during drawing, but if the electron beam is used for a long time, for example 1
When blanking is performed for more than a second, the current of the irradiation lens system 3 may be changed continuously or stepwise from a value optimal for drawing to a value optimal for blanking.

Furthermore, instead of changing the current of the irradiation lens system 3 to change the focusing position, or in addition to this current control, the position of the electron collection housing 8 may be moved upward.

〔Effect of the invention〕

As described above, in the apparatus of the present invention, the current of the electron lens system is controlled so that the electron collection housing is as large as possible, so leakage electron beams can be reduced and unnecessary exposure can be avoided. The present invention has excellent effects such as being able to prevent this.

[Brief explanation of drawings]

Figure 1 is a schematic diagram of an electron beam exposure apparatus according to the present invention, Figure 2 (a) shows the relationship between the current value for the irradiation lens system and the electron beam focal point during blanking, and Figure 2 (b)
3 is a graph showing the relationship between the current value for the electron lens system and the voltage value of the electron collection housing, and FIG. 3 is a schematic diagram of a conventional electron beam exposure apparatus. 2...Electron gun 3...Irradiation lens system 4.
...Blanking deflection system 5...Objective lens system 6...
-Scanning deflection system 7...Sample 8...Electron collection casing In the drawings, the same reference numerals indicate the same or equivalent parts.

Claims (1)

[Claims] (1) The electron beam emitted from the electron beam generation means is focused by an electron lens system, and is projected onto the surface of the workpiece to expose it. When the exposure by the electron beam is interrupted, the electron beam is used by the blanking deflection means. In the electron beam exposure apparatus configured to deflect the electron beam toward the inside of an electron collection housing, current control for the electron lens system is performed so that the amount of electrons collected by the electron collection housing is as large as possible when exposure is interrupted. An electron beam exposure apparatus characterized by comprising a control section that performs the following operations.