JPS59181019A - Electron beam exposure device - Google Patents

Abstract

PURPOSE:To draw the minute pattern with accuracy by correcting distortion of the beam by arranging a deflection correcting means for controlling a direction of a side or a crossing angle of a polygonal pattern projected on a sample through a mask. CONSTITUTION:An electron beam 5 emitted from a filament in a cathode 1 penetrates a slit 7 of a first mask 6 through an aperture 2a and an aperture 3a of an anode 2 composing a focusing lens. A rectangular beam 8 projects a first rectangular beam pattern in a position displaced regarding a slit 13 of a second mask 12 by a variable rectangle deflector deflecting means 10 through a focusing lens 9 which is the first electronic lens. This beam pattern is the rectangular pattern having the predetermined area ratio. Deflection correcting means 31 and 33 to correct the rectangular pattern distortion by extending and shortening sides or a crossing angle part with two sides of said pattern are arranged.

Description

DETAILED DESCRIPTION OF THE INVENTION (1) Technical Field of the Invention The present invention relates to an electron beam exposure apparatus, and more particularly to an electron beam exposure apparatus having a variable area type electron beam projection image orthogonality correcting means.

(2) Background of the Technology Recently, variable area type electron beam exposure apparatuses that use electron beams to change the shape of the beam cross section have come into widespread use. As shown in FIG. 1, this variable area electron beam exposure apparatus basically obtains, for example, a rectangular projection beam 19 by means of two masks 6.12 having, for example, square or rectangular slits 7.13.

That is, the beam 5 emitted from the electron beam source of the cathode 1 passes through the grid 2, passes through the focusing lens 3, passes through the crossover point 4, and passes through the slit 7 of the mask 6. For example, a rectangular beam 8 is connected to the focusing lens 9 and the variable rectangular Deflection means 10
The deflection current applied to the slit 1 of the mask 12
It is projected at a position displaced with respect to 3.

As a result, a beam 15 having a cross-sectional shape 14 corresponding to the superposition of the projection patterns of the slit 13 and the slit 7 is taken out from the slit 13, and the beam 18 is reduced and projected onto the sample 20 through the focusing lens 16, and the beam 18 is projected onto the sample 20 in a reduced size.
9 and the beam 18 is digitally scanned by the deflection means 17.

In the variable area type electron beam exposure apparatus constructed in this way, there is a problem in that both sides of the pattern 19 projected onto the sample are not exactly 90 degrees, which causes various problems when generating patterns for LSIs and the like.

(3) Prior art and problems In the above-mentioned variable area electron beam exposure apparatus, when the pattern 19 projected onto the sample 20 is sequentially scanned to draw, for example, one line, the arrow as shown in FIG. When the rectangular pattern is moved in the input direction 19.19', 19'/, the projected pattern that should be at the position shown by the broken line shifts and comes to the position shown at 19a, and the pattern is distorted as shown at 19b. This makes it impossible to draw a straight line. For example, if the width W of the pattern 19 is 0.5μ and the length L is 4μ, then ΔL
= 0.05μ, or θ-0.6°, otherwise it would be difficult to manufacture normal LSIs.
However, suppressing the angle to θ-0.6° involves quite difficult problems.

Normally, beam axis deviation and non-uniform magnetic fields occur due to factors such as the processing accuracy of the slit, the mounting position and processing accuracy of the lens system.

FIG. 3 is an enlarged plan view of the mask 12 shown in FIG. 1, but the processing accuracy of the rectangular slit 13 is poor, and θ2=0°6°.
If the above deviation occurs and the machining accuracy of the slit 7 of the mask 6 is also poor, resulting in a deviation of θ+=0.6° or more, the pattern 14 projected onto the mask 12 through the mask 6 will be trapezoidal as shown in the diagonal diagram. It's not a perfect rectangular pattern.

For this reason, there was a drawback that both sides of the beam were not exactly at right angles.

(4) Purpose of the Invention In view of the above-mentioned conventional drawbacks, the present invention provides an electron beam exposure apparatus that can correct the horizontal and vertical sides of a pattern projected onto a sample so that they are perfectly perpendicular using a correction deflection means. The purpose is to provide the following.

(5) Structure and object of the invention According to the present invention, in a variable area electron beam exposure apparatus having a mask having a slit in an electron beam passage path and a changing means, a variable area electron beam exposure apparatus is provided which is disposed toward the sample from the mask. An electron beam exposure apparatus characterized in that a deflection correction means is provided for controlling the direction of sides or intersection angles of the polygonal pattern projected onto the sample through the mask up to the vicinity of the first electron lens. achieved by.

(6) Examples of the invention An embodiment of the present invention will be described in detail below with reference to the drawings.

FIG. 4 is a block diagram of the electron beam optical system of the electron beam exposure apparatus of the present invention, FIG. 5 is a pattern plan view showing another embodiment similar to that in FIG. 5, and FIG. 7 is a diagram showing a corrected electron beam in a mask portion. In FIG. 4, the same parts as in FIG. I will explain.

The electron beam 5 emitted from the filament in the cathode 1 passes through the aperture 2a of the grid and the aperture 3a of the anode 2 constituting the focusing lens and passes through the slit 7 of the first mask 6.For example, the rectangular beam 8 is A first rectangular beam pattern is projected onto a position displaced with respect to the slit 13 of the second mask 12 by a variable rectangular deflector deflection means 10 through a focusing lens 9 which is a first electron lens, and a predetermined area is projected. A rectangular pattern of ratio.

23 is an electron lens, and the electron beam 15 passing through the slit 13 of the second mask 12 is passed through the electron lens 24.25.
After passing through a projection lens 16, a pattern 19 is projected onto the sample 20. The electron lens 25 is positioned by a deflection means 17 such as an electromagnetic deflection means 26 and an electrostatic deflection means 27, and astigmatism and focus are corrected by stingmatol electrodes 28, 30 and a focus electrode 29.

In the present invention, a deflection correction means for correcting rectangular pattern distortion is provided by expanding and compressing a side of a pattern or an intersecting angle portion with two sides using an electromagnetic deflection correction means consisting of two poles, four poles, or eight poles. to be placed. Such deflection correction means 31 and 33 are such that an electron beam 8.15 irradiated downward in a certain direction of the sample from a mask 6.12 having a first or second slit 7.13 is directed to a first electron lens 9. ，
32. until near the bottom passing through the part where 24 is installed.
It is only necessary to dispose it within a range of 34 degrees, and it is most preferable to arrange it in the vicinity of the lower part of the first and second masks at 6 degrees 12 degrees.

The electromagnetic deflection correction means may include, for example, four
For example, the pattern 14 (see FIG. 1) of the electron beam that has passed through the first or second mask as shown in FIG. 5(a) consists of coils 31a, 31b, 3.
1c, 31d (33a, 33b, 33c, 3
3d) The magnetic pole N caused by the direction of the current flowing in.

By compressing or expanding the sides of the beam according to S, the broken line 14a
, 14b, it becomes possible to deform the beam. In the above embodiment, the coils were arranged at positions facing the sides of the pattern 14, but as shown in FIG. (33
e.

33f, 33g, 33h), the electron beam pattern 14 can be transformed as shown by the broken line 14C.

That is, the patterns 14a and 14b are conversely distorted.

It is also possible to return 14C to the correct pattern 14.

Figure 6 shows 8-pole coils 31a to 31h, 33a to 33h.
are arranged to face the sides of the pattern 14 and the intersections perpendicular to the two sides.

The correction state in the actual optical system is as shown in FIG. 7. The electron beam 15 transmitted through the slit 13 of the mask 12 is bent near the coils 31 and 33 of the deflection correction means, and the position of the crossover point 34 is changed to create a pattern. 19 is corrected as in 19a.

In the above embodiments, 4-pole and 8-pole coils are described in detail, but it is of course possible to use a 2-pole coil, and the deflection means 31
．． It is clear that only one of 33 may be disposed on the electron beam path.

(7) Effects of the Invention As explained in detail above, the electron beam exposure apparatus of the present invention corrects beam distortion caused by the precision of the slit of the mask or the processing precision and placement precision of the lens system, thereby achieving accurate beam exposure. It has a feature that makes it possible to draw fine patterns.

[Brief explanation of the drawing]

Fig. 1 is a configuration diagram of the projection optical system of a conventional electron beam exposure apparatus, Fig. 2 is a pattern plan view for explaining the deviation and distortion of a rectangular beam pattern to be drawn on a sample, and Fig. 3 is a diagram of the projection optical system of a conventional electron beam exposure apparatus. FIG. 4 is an enlarged plan view of the mask shown in FIG.
l (bl is a pattern plan view showing a method of correcting an electron beam pattern transmitted through a mask having slits, FIG. 6 is a pattern plan view showing another example similar to FIG. 5, and FIG. 7 is a pattern plan view of a mask portion) It is an optical system configuration diagram showing a corrected electron beam. 1... Cathode 2... Grid 3... Anode 6... First mask 7.13... Slit 9.23.24.25.・Electronic lens
10.17...Deflection means 12...Second mask
16... Projection lens 26... Electromagnetic deflection means
27... Electrostatic deflection means 28. 30... Stigmatol electrode 29... Focus electrode 31.33.
...Deflection means 31a to 31h, 33a to 33h
...Coil Figure 2 Figure 3 11 IJ ]l Figure 5 (a) (1)) Figure 6 31c (33c) Figure 7 1! :la

Claims (2)

[Claims] (1) In a variable area electron beam exposure apparatus having a mask having a slit in the electron beam passage path and a deflection means, a first
An electron beam exposure apparatus characterized in that a deflection correction means is provided for controlling the direction of a side or an intersection angle of a polygonal pattern projected onto the sample through the mask up to the vicinity of the second electron lens. (2) The electronic device according to claim 1, further comprising two masks having the slits, and two deflection correction means for controlling the directions of sides or intersection angles of the polygonal pattern. Beam exposure equipment.