JPS61154033A - Method and apparatus for x-ray exposure - Google Patents

Abstract

PURPOSE:To enhance exposure efficiency and enable the increase of throughput by giving exposure treatment that involves the displacement of a X-ray beam relative to both of the sample to be exposed and the mask, and in the direction of the short side of the radiation field, namely, in the lateral direction of the V-shaped groove for the purpose of giving the optimum contour of the radiation field. CONSTITUTION:A target 1 rotates with a high speed along the circumferential direction of the groove 2 having a V-shaped cross-section. A sample to be exposed 4 is placed on a stage 3 below the target 1 and a resist film 5 is formed by coating on the surface of the sample, above which a mask 6 is supported. A part of the X-ray source containing the target 1 undergoes reciprocating motions in the direction crossing the V-shaped groove 2, namely, that of the rotation axis of the target 1. The reciprocating a motions are uniform motions which are set to repeat reciprocations at least once an exposure. The X-ray beam 7 is shifted every reciprocation to form a roughly circular intensity distribution of X-rays. As the results, the effective radiation field forms a square, enabling effective exposures.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an X-ray exposure technology that is expected to be used as a transfer technology for fine patterns of semiconductor integrated circuit devices, etc., and particularly relates to an X-ray exposure technology that is expected to be used as a transfer technology for fine patterns of semiconductor integrated circuit devices, etc., and in particular, to expand the effective area of the exposure field. The present invention relates to an exposure method and an exposure apparatus.

Microfabrication technology for realizing fine, high-density patterns for semiconductor integrated circuit devices and the like is a combination of resist patterning technology and etching technology for semiconductor substrates and the like using this resist pattern as a mask.

X-ray exposure methods are attracting attention as an exposure method for realizing submicron resist patterns. This is because X-ray exposure methods have the potential for inherently higher resolution than other exposure methods, higher throughput than electron beam exposure methods, and are capable of proximity exposure due to fewer diffraction and interference effects. by.

In order to put this excellent possibility into practical use as soon as possible, development is underway to improve not only quality such as pattern resolution but also throughput.

[Conventional technology]

The X-ray exposure device is equipped with an X-ray source and an aligner, and projects a transfer pattern provided on a mask onto a resist. An electron beam impact type X-ray generator is usually used as this X-ray source, and for example, the structure shown in FIG. 2 has been reported.

In the figure, reference numeral 11 denotes a target, which is formed into a conical shape using, for example, palladium (Pd).

An electron beam 12 is made to collide with the inner surface of the target 11 as schematically shown in the figure, and X-rays are irradiated downward. A nozzle 13 is provided with a small gap to the outer surface of the target 11, and the target 11 is cooled by a jet water stream.

In the X-ray source with this structure, there is a high probability that the first collision is not an effective collision that generates X-rays, but that the electrons reflected by the target 11 repeatedly collide and generate X-rays, and the Xg generation efficiency is good. However, the X-ray output is limited due to insufficient cooling effect, making it impossible to achieve the throughput required for the XwA dew tip.

In order to deal with such problems, the applicant of the present patent has previously provided an X-ray generating apparatus in Utility Model Application No. 58287/1987, which has high X-ray generation efficiency and cooling effect and can provide high output.

The X-ray generator is equipped with a mechanism for rotating a target 1, as shown in FIG. A high Xf! generation efficiency is obtained by re-collision of electrons within the groove 2 with a V-shaped cross section, and a high cooling effect is obtained by sequentially moving and cooling the position heated by the electron collision. As a result, an increase in X-ray output has been achieved.

[Problem that the invention seeks to solve]

The V-groove rotating target method is promising as an X-ray source for an X-ray exposure apparatus because it can provide high output. However, the intensity distribution of the XwA beam obtained from the X-ray source with this structure becomes an ellipse whose short side is the width direction of the groove, as illustrated in FIG. 3(b).

In order to obtain a highly accurate exposure pattern in X-ray exposure processing, the maximum and minimum width (peak to peak) must be 4%.
Since it is necessary to confine the exposure field within a certain intensity distribution, an elliptical X-ray intensity distribution results in an effective exposure field 9 having a rectangular shape.

This effective exposure field 9 is, for example, 10 m+*
20, and it is often difficult to use the exposure field efficiently, or the exposure field is insufficient for the chip area, so it is desired that the effective exposure field be square. .

[Means for solving problems]

The above-mentioned problem is solved by using an X-ray source that has a groove-shaped recess with a ``■'' cross section, is provided with a target that rotates in the length direction of the recess, and generates an X-ray beam by colliding an electron beam with the recess. , an X-ray exposure method according to the present invention, in which exposure is performed while displacing the X41m beam in the width direction of the concave portion relative to the sample to be exposed and the mask.

In addition, a groove-shaped recess with a ■-shaped cross section is formed, a target is provided that rotates in the length direction of the recess, and an XIs source is provided that collides an electron beam with the recess to generate an X-ray beam. This problem is solved by the X-ray exposure apparatus according to the present invention, which includes means for displacing the X-ray beam in the width direction of the recess relative to the sample to be exposed and the mask.

[For production]

According to the present invention, when using the V-groove rotating target type X-ray source according to the invention, the X-ray beam is directed in the short side direction of the exposure field, that is, in the direction of the short side of the exposure field, relative to the sample to be exposed and the mask. Exposure processing is performed while displacing in the width direction of the groove.

This displacement of the X-ray beam can be realized, for example, by displacing at least a part of the X-ray source relative to the sample to be exposed and the mask, in particular by making a reciprocating motion. The light may be incident on a heavy metal reflective surface such as gold at a low angle, reflected once, and the reflective surface may be displaced.

The velocity distribution of this displacement movement can be selected to an optimal value, and this displacement expands the short side direction of the exposure field, making it possible to perform X-ray exposure with the maximum and minimum widths within the permissible value for a square field, for example. It can be carried out with great efficiency.

〔Example〕

The present invention will be specifically explained below using examples.

FIG. 1(a) is a schematic diagram showing an embodiment of the present invention (in the same figure)
2 is a plan view showing an example of the X-ray intensity distribution and effective exposure field on the resist surface. FIG.

In the same figure (al), the shape of the target 1 is the same as that of the above invention, and the length direction of the groove 2 having a V-shaped cross section is, for example, 15 mm.
It rotates at a high speed of about 000 rpm. A sample 4 to be exposed is placed on a stage 3 below a target 1, and a resist film 5 is coated on its upper surface. Furthermore, a mask 6 is supported on the sample 4 to be exposed.

In this embodiment, a part of the X-ray source including the target 1 is caused to reciprocate in the width direction of the groove 2 having a V-shaped cross section, that is, in the direction of the rotation axis of the target blade 1. This reciprocating motion is a uniform motion, and the amplitude thereof is, for example, about ±611111, and the cycle is set to at least one reciprocation during one exposure.

Due to this reciprocating movement, the X-ray beam 7 is displaced as shown in FIG. 1, and the X-ray intensity distribution becomes approximately circular as shown in FIG. As a result, the effective exposure field 8 becomes approximately square, making it possible to efficiently perform exposure of an area of, for example, 2 (1ws x 20wv+).

In the embodiment described above, a part of the X-ray source including the target 1 is made to reciprocate, but the same effect can be obtained even if this is fixed and the sample to be exposed 4 and the mask 6 are made to make reciprocating movements. I can do it. Further, the reciprocating motion of the X-ray source etc. does not necessarily have to be linear motion, but may be reciprocating motion on an arc.

〔Effect of the invention〕

As explained above, according to the present invention, although a large output can be obtained as an X-ray source for an X-ray exposure apparatus, a V-groove rotating target X-ray source whose X-ray beam has an elliptical intensity distribution is used. It is now possible to control the exposure field to the optimal shape to improve efficiency and increase throughput.
Great effects can be obtained in realizing X-ray exposure.

[Brief explanation of the drawing]

FIG. 1(a) is a schematic diagram showing an embodiment of the present invention, FIG.
) is a plan view illustrating the exposure field, FIG. 2 is a sectional view showing a conventional example of an X-ray source, FIG. 3(a) is a side view illustrating a V-groove rotating target, and FIG. FIG. 3 is a plan view illustrating the exposure field. In the figure, 1 is a V-groove rotating target, 2 is a groove with a V-shaped cross section, 3 is a stage, 4 is a sample to be exposed, 5 is a resist film, 6 is a mask, 7 is an X-ray beam, 8 and 9 are effective Shows the exposure field. ￥-1tl

Claims (1)

[Scope of Claims] 1. An X-ray device in which a groove-shaped recess with a V-shaped cross section is formed, a target is provided that rotates in the length direction of the recess, and an electron beam collides with the recess to generate an X-ray beam. An X-ray exposure method characterized in that exposure is performed using a source while displacing the X-ray beam in the width direction of the recess relative to the sample to be exposed and the mask. 2. A groove-shaped recess with a V-shaped cross section is formed, a target is provided that rotates in the length direction of the recess, and an X-ray source is provided that generates an X-ray beam by colliding an electron beam with the recess. An X-ray exposure apparatus comprising means for displacing the X-ray beam in the width direction of the recess relative to the sample to be exposed and the mask.