JPS60214529A - X-ray generating device - Google Patents

Abstract

PURPOSE:To uniformize the temperature distribution in the strip-form filament at the output time of an electron beam and to equalize the beam current distribution in the filament by a method wherein the sectional area of the strip-form filament in the vicinities of both end parts of the filament is made to reduce. CONSTITUTION:An electron beam 7, which generates from a stripped filament 1, is focussed by a Wehnelt cathode 2, the electron beam 7 is further deflected by a deflecting electrode 4 and collides on an electron beam irradiating surface 9 on the surface of an opposed cathode 3. X-rays generate by the collision of this electron beam 7 with the opposed cathode 3. The X- rays pass through a solar slit 12 and an X-ray mask 11 and incide in a resist 5 to expose. The stripped filament 1 has been provided with apertures 10 and the sectional area of the filament 1 in the neighborhoods of the apertures 10 has been made smaller. Therefore, the heat resistance of the parts is increased and heat is prevented from escaping to the filament holder. Moreover, as electrical resistance is also increased in the parts, in the neighborhoods of which the sectional area of the filament 1 has been made smaller, the heat value of the parts is augmented and it is prevented that the temperature distribution in the filament 1 drops towards both ends of the filament 1 from its central part. As a result, the temperature distribution in the longitudinal direction of the strip form filament 1 can be equalized, and the beam current distribution can be also uniformized.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of the Invention) The present invention relates to an X-ray generator that generates X-rays by colliding an electron beam emitted from a strip filament with an anticathode. The present invention relates to an X-ray generator that makes the X-rays uniform and prevents uneven burns during X-ray exposure.

(Background of the Invention) Conventionally, X-ray exposure technology has been known as one of the techniques for transferring fine circuit patterns for semiconductor devices and the like.

Soft X-rays have a much shorter wavelength than light and can easily pass through organic matter, making it easy to solve problems with phenomena such as reflection, interference, and diffraction when performing submicron lithography using light exposure.

However, the X-ray exposure method also has several problems in the manufacture of semiconductor devices, and one of the main ones is uneven burning of the resist. Currently, an X-ray generator using a band-shaped filament with a linear focus has been proposed in the X-ray exposure method, but the problem of uneven exposure has not yet been solved.

A conventional example will be explained below with reference to the drawings.

FIG. 1 is an external view of a soft X-ray generator using a band-shaped filament with a linear focal point, and FIG. 2 is a schematic diagram of a regular X-ray exposure device using a Solar slit. In FIGS. 1 and 2, 1 is a strip filament that emits an electron beam 7, 2 is a Wehnelt that focuses the electron beam 7, 3 is an anticathode, and 4 is a deflection electrode. 8 is an X-ray, 9 is an electron beam 7
is the electron beam irradiation surface that collides with the anticathode 3. 11 is an X-ray mask; 12 is a solar slit; and 5 is a resist coated on a wafer 6.

In the X-ray exposure apparatus shown in FIG. 2, electrons 1! +! 7 is focused by the Wehnelt 2, further deflected by the deflection electrode 4, and collides with the electron beam irradiation surface 9 on the surface of the anticathode 30. When this electron beam 7 collides with the anticathode 3, X-rays 8 are generated, which pass through the solar slit 12 and the X-ray mask 11 and enter the resist 5 for exposure.

At this time, murayaki (-) is the X-ray 8 incident on the resist 5.
The non-uniform X-ray dose distribution of 1.1 s r et al.

This non-uniformity of X-ray dose distribution 1. t, electron beam oil surface 9
1-2aE Keru electron ¥! + degree A11 is uniform (゛It can be solved if the electron density distribution is uniform = the beam current distribution generated from the band-like noise 1 must be uniform. Furthermore, the beam current distribution must be uniform. In order to achieve this, it is necessary to make the temperature distribution in the length direction of the strip filament 1 uniform.

However, the strip filament 1 of the conventional X-ray generator is
As shown in Figure 3, many structures are simply bent thin plates of tantalum, tungsten, etc. with uniform thickness and uniform width. Since heat is conducted from the holding portion A of filament 1 to the holder, a phenomenon occurs in which the temperature decreases from the center of filament strip 1 toward both ends. That is, in the conventional belt-shaped filament, since the temperature distribution in the length direction is not uniform, the beam current distribution is also not uniform, and therefore the incident xsut distribution is also non-uniform, resulting in uneven burning.

(Objective and Summary of the Invention) In view of the above-mentioned problems of the conventional method, the present invention aims to provide an X
In an X-ray generator that generates rays, by reducing the cross-sectional area near both ends of the strip filament, the thermal resistance and electrical resistance of the filament 1 to the front part of the holder holding part are increased, and the output of the electron beam is increased. The purpose is to make the temperature distribution of the strip-shaped filament uniform and the beam current uniform, and it can prevent uneven firing (') when used in X-ray exposure equipment that transfers patterns of semiconductor devices, etc. be.

(Explanation of Examples) Hereinafter, the present invention will be described in detail based on the drawings.

FIG. 4 shows the structure of a strip filament according to an embodiment of the present invention. The filament strip 1 in the same figure is as shown in FIG.
There is a frontage 10 provided in the building.

By carrying out such processing, the cross-sectional area becomes small near the opening 10, so the thermal resistance of this part becomes large. conduction is suppressed and heat is transferred from ficimen 1 to holder (not shown)
prevent them from escaping. In addition, in the portion where the cross-sectional area is reduced, the electric resistance 11 (resistance) is also increased, so the heat generation area of the 4 portions increases, and the temperature is prevented from decreasing from the center of the filament 1 toward both ends.

Therefore, by using the filament shown in FIG. 4 as the strip filament 1 of the X-ray generator shown in FIG. 1 or the X-ray exposure device shown in FIG. Since it is possible to make the beam current distribution uniform, the X-ray dose distribution incident on Regimes 1 to 5 can be made uniform and uneven burns can be eliminated.

5 to 7 show other embodiments of the belt-like filament according to the X-ray 1 generator of the present invention.

In the filament shown in FIG. 5, a notch 10' is provided in place of the opening shown in FIG. 4, but the same effect as that shown in FIG. 4 can be obtained.

That is, the strip filament 1 of the present invention has both ends (=
Any shape may be used as long as it increases the thermal resistance and electrical resistance in the vicinity of 1, and as a result, the temperature distribution in the length direction of the filament strip 1 becomes uniform. For example, as shown in FIG. 6, there are large notches 10' at both ends.
Alternatively, as shown in FIG. 7, both the notch 10' and the groove 10 may be provided, or the thickness may be reduced.

Although the upper part is intended to be applied to soft X-ray exposure, it can also be used as a radiation source for inspection equipment.

(Effects of the Invention) As explained above, according to the present invention, the cross-sectional area near both Di: portions of a belt-shaped filament having a uniform thickness and a uniform width can be reduced. 1. Band-shaped neuramen during electron beam emission]
In the length direction of The line distribution becomes uniform. Eliminating the uneven firing ('J) during exposure of semiconductor laminations, etc., improves the -i1 function and improves the yield in the manufacturing process of semiconductor devices, etc.

[Brief explanation of drawings]

Figure 1 is an external view of a conventional X-ray generator using a band-shaped filament with a linear focal point, Figure 2 is a schematic diagram of an X-ray exposure apparatus using Solar Slip i, and Figure 3 is a conventional X-ray generator. FIG. 4 is a perspective view of a filament strip according to an embodiment of the present invention. FIGS. 5 to 7 are perspective views of modifications of the filament strip shown in FIG. 4. 1... Band-shaped filamen 1~. 2... Wehnelt, 3
... Anticathode, 4... Deflection electrode, 5... Resist 1
6... Wafer, 7... Electron beam, 8... X-ray, 9...
...Electron beam irradiation surface, 10; ...opening, 10'...notch, 11...X-ray mask, 12...solar slit. Patent Applicant Canon Co., Ltd. Agent Patent Attorney Nobuo Ito Agent Patent Attorney Tetsuya Ito

Claims (1)

[Scope of Claims] 1. An X-ray generator that has a band-shaped filament and generates X-rays from the anticathode by colliding an electron beam emitted from the band-shaped filament with an anticathode, comprising: both ends of the band-shaped filament; An X-ray generator characterized by a reduced cross-sectional area in the vicinity. 2. The X-ray generator according to claim 1, wherein the cross-sectional area is reduced by providing openings or notches near both ends of the filament strip.