JPS6261328A - Charged beam exposure device - Google Patents

Abstract

PURPOSE:To enable any characteristic error level peculiar to each beam to be corrected by a method wherein a fine deflector deflecting individual small beam at fine level is provided near a planking electrode. CONSTITUTION:A fine deflector 4 is provided near a planking electrode 3 to calculate each beam correction level synchronized with beam scanning making reference to the coefficient for detecting the beam correction level preliminarily calculated and the deflected positions for correction by the fine deflector 4. Through these procedures, patterns without any distortion and disconnected parts can be formed with high precision.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an apparatus that deflects a charged beam and draws a pattern in charged beam exposure, and particularly relates to an apparatus that performs exposure using a large number of charged beams.

[Technical background of the invention and its problems]

Currently, single-beam systems are the mainstream for charged beam exposure equipment, but one of the drawbacks is poor throughput, and as a solution to this, a multi-beam system that can expose multiple areas at the same time is proposed. Proposed. The writing speed of the multi-beam method is twice as fast as the number of small beams compared to the conventional raster scan and Gaussian single beam methods with similar blanking frequencies, and it is faster than the similar variable shaped beam and pectascan methods. By increasing the number of beams, it is possible to increase the drawing speed.

FIG. 2 shows one configuration of a multi-beam exposure apparatus. In the multi-beam exposure apparatus having this configuration, a charged beam generated by the single electron gun 20 is divided to obtain a group of small beams.
A blanking electrode 3 provided for each of these small beams and a deflector 8 that collectively scans the group of small beams cause each beam to draw a separate pattern as shown in FIG.

Here, the shaded area in FIG. 3 indicates a non-blanking area, and the circle indicates a small beam spot.

However, due to the characteristics of the objective lens of the above-mentioned deflector, deflection distortion and deflection position deviation occur that are unique to each beam and cannot be corrected by the above-mentioned deflector.

Until now, these error amounts were sufficiently small compared to 1 degree of the device, but they can no longer be ignored when trying to improve accuracy.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a charged beam exposure apparatus that makes it possible to correct errors that are unique to each beam and which cannot be corrected by a single multi-beam exposure apparatus.

[Summary of the invention]

In order to achieve the above object, in the present invention, as shown in FIG. 1, a micro-deflector is provided near the blanking electrode to deflect each small beam by a minute amount, and each small beam is corrected separately. Using each beam correction coefficient determined in advance, the amount of correction for each beam is determined in synchronization with beam scanning, and the amount of correction is provided to the micro deflector.

〔Effect of the invention〕

According to the present invention, in a multi-beam exposure apparatus, it is possible to correct the amount of error peculiar to each beam, and it is possible to obtain a more accurate drawing pattern.

[Embodiments of the invention]

FIG. 2 is a configuration diagram showing an embodiment of the present invention.

20 is an electron gun that emits an electron beam as a charged beam;
1 is a beam splitting gauze lens, 2 is a converging gauze lens,
3 is a blanking electrode, 4 is a micro deflector which is a feature of the present invention, 5 is a converging gauze lens, 6 is a reduction lens, 7 is an objective lens, 8 is a deflector, 9 is a sample, 10 is a table drive system, 11 1 is a blanking control circuit, 12 is a correction calculation circuit, 13 is a deflection control circuit, 14 is a table position length measuring device, 1
5 is a table control system, and 16 is a computer. This device splits and focuses the beam using three gauze lenses 1.2.5. A blanking electrode 3 for each small beam inside the second gauze lens 2 and a deflector 8 common to all small beams.
This causes each beam to draw separate patterns simultaneously, as shown in FIG.

In this type of multi-beam 4-light device, it is possible to draw different patterns simultaneously on each small beam using one electron optical system, and since it is a raster scan, the drawing time does not depend on the complexity of the pattern to be drawn. do not.

In an actual multi-beam exposure apparatus using this type of system, as shown in Figures 4 and 5, distortion occurs in the relative position of each beam on the sample surface and in the deflection area of each beam by 3 degrees. , distortion of the drawn pattern, cutting of the pattern, etc. occur.

Such errors are unique to each beam and require a unique amount of correction to be applied to each beam, making it impossible to correct the deflection data.
Although the correction for blanking data is somewhat effective, it is difficult to replace the blanking data of adjacent beams, and if the boundaries of the deflection areas of adjacent beams are separated, the correction is not effective. Impossible is not perfect.

For this reason, in the present invention, as shown in Fig. 1, a minute deflector is provided near the blanking electrode, and beam scanning is synchronized by using coefficients for calculating each beam correction amount determined in advance and the deflection position. Then, each beam correction amount is calculated, and the correction is performed using a micro deflector.

With this method, it was possible to form a highly accurate pattern without distortion or cut points without changing the blanking data.

Needless to say, the micro deflector 4 is effective for alignment between gauze lenses in addition to the above-mentioned applications.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing an embodiment of the present invention, Fig. 2 is a block diagram showing a conventional device, Fig. 3 is an explanatory diagram showing a normal drawing method, and Fig. 4 is a relative diagram of the beam position. An explanatory diagram showing the error,
FIG. 5 is an explanatory diagram showing the distortion state of the deflection area of the small beam. 20...Electron gun, 4...Minute deflector, 9...
·sample. Agent Patent Attorney Nori Chika Yudo Kikuo Takehana Figure 3

Claims (2)

[Claims] (1) having means for obtaining a large number of charged beams, means for blanking the beams individually, means for converging the beams on the sample surface, and deflection means for deflecting the beams all at once; The charged beam exposure apparatus that irradiates the sample surface with a charged beam to draw a desired pattern is characterized in that the charged beam exposure apparatus includes a minute deflection means that individually deflects the beam by a minute amount in the vicinity of the blanking means. Charged beam exposure equipment. (2) The charged beam exposure apparatus according to claim 1, wherein the micro deflection means is provided with a correction amount for deflection distortion and deflection position specific to each of the beams.