JPH04239717A - X-ray aligner - Google Patents

Abstract

PURPOSE:To see that the degree of the condensation does not change by the rocking of a mirror 1, though there was such a case that the degree of the condensation in horizontal direction of a radiation changed accompanying the change of the rocking angle in case of having scanned it with a synchrotron radiation so as to expose it while rocking a radiation reflecting mirror 1, which has a recessed cylindrical reflecting face. CONSTITUTION:This is so arranged that the length of a perpendicular OC let down from a light emitting point O to the extended contact surface of a mirror face ridge may be always constant by making the center W of the rocking of a mirror 1 accord with a light emitting point O. Since the length of the above perpendicular OC becomes constant at all times, the degree of the condensation in horizontal direction of the reflected synchrotron radiation ceases to change together with the rocking of the said mirror 1.

Description

[Detailed description of the invention]

0001

[Field of Industrial Application] This invention relates to an X-ray exposure apparatus that performs exposure using synchrotron radiation, and in particular, it focuses synchrotron radiation that spreads in the horizontal direction while exposing a plate-like object to be exposed. If there is a configuration that expands the irradiation area of the radiation light for the group, it is an object of the present invention to improve the configuration.

0002

[Prior Art] When a mask pattern is exposed on a wafer resist surface using synchrotron radiation, the synchrotron radiation is emitted from a light source in a horizontally flat state, so a cylindrical concave reflective surface is used. Using multiple synchrotron radiation reflecting mirrors, the concave surfaces converge the spread of the synchrotron radiation in the horizontal direction.At the same time, the multiple synchrotron radiation reflection mirrors scan while correcting uneven illumination, etc., and irradiate in the vertical direction. Equipment configurations that extend the area may be used.

FIG. 7 shows a case in which the synchrotron radiation reflecting mirror 1 having a cylindrical concave reflecting surface as described above is equivalently constructed as one sheet for an exposure apparatus that carries out such an X-ray exposure method. It shows. As shown in the figure, synchrotron radiation emitted from a light source such as the electron storage ring 20 is focused in the horizontal direction by the synchrotron radiation reflecting mirror 1 whose oscillation center is near the radiation reflecting surface. While being
and is scanned in the vertical direction by the rocking of the mirror 1,
As a result, the irradiation area of the synchrotron radiation is expanded.

004

However, according to the X-ray exposure apparatus as described above, the degree of horizontal condensation of synchrotron radiation light varies depending on the change in the swing angle of the synchrotron radiation reflection mirror 1. 8, and there is a problem that the irradiation range, illuminance, and illuminance unevenness on the mask and wafer surface vary depending on the scanning position (X in the figure).
The range indicated by is the required exposure range, and the range indicated by Y is the irradiation range). If it is attempted to maintain uniform illuminance with such a configuration, it is necessary to control the swinging speed of the synchrotron radiation reflection mirror 1 to a large extent and in a complex manner, making it unsuitable for application to actual equipment. do not have.

The present invention was devised in view of the above-mentioned problems of the prior art, and it investigates the causes of changes in the degree of convergence of synchrotron radiation using these technologies, and based on the results, it solves such problems. This paper attempts to propose a configuration of an X-ray exposure apparatus that does not undergo any changes.

[0006]

[Means for Solving the Problems] According to the present inventor, the change in the degree of convergence of synchrotron radiation as described above is basically caused by the convergence/divergence phenomenon of light on a reflecting mirror having a cylindrical concave reflecting surface. It is thought that it can be understood as follows. That is, first, if the radius of curvature of the cylindrical surface of such a reflecting mirror 10 is R, then as shown in FIG.
If the mirror is placed at a position R/2, which is half of R/2, the rays reflected by the mirror surface will become parallel rays. In addition, as shown in FIG. 10, the light source O
If the position of O is moved closer to the center of curvature Z than the position of R/2, the reflected light will be more condensed, and conversely, if the light source O is moved closer to the mirror surface than the position of R/2, Reflected light is spread out more than parallel light.

[0007] If we consider the above-mentioned light convergence/divergence phenomenon by replacing it with the example of synchrotron radiation (X-ray exposure apparatus) as shown in FIGS. If the center W is near the mirror reflection point M of the synchrotron radiation light, then the length OC of a perpendicular drawn from the light source emission point O to the extended tangential surface of the ridgeline of the mirror surface
changes like OC' as the swing angle of the mirror changes. This length OC or OC' corresponds to the length OC shown in FIGS. 9 and 10 (in the vertical section of the mirror 1 shown in FIGS. 9 and 10, the length OC is exactly the same as that shown in FIGS. (corresponding to the length OC or OC' shown in 12), the reason why the degree of horizontal convergence of synchrotron radiation light changes with the change in the swing angle of the mirror 1 mentioned above will be explained. is attached. Therefore, regardless of the movement of the synchrotron radiation reflecting mirror 1, if the OC = constant relationship holds, the radiation component in the vertical cross-sectional direction of the cylindrical mirror 1 even on the mask or wafer surface will be the reflected synchrotron radiation with a constant degree of convergence. Become. Incidentally, since the mirror 1 has no curvature in the longitudinal direction, there is no condensation due to reflection, and the synchrotron radiation light is reflected almost as is.

[0008] Based on the above circumstances, the following configuration of the present invention was devised.

That is, in the X-ray exposure apparatus of the present invention, as shown in FIG.
It is distinctive in that it has a structure that allows it to oscillate.

Further, in the configuration of the second invention, as shown in FIG. 2, the light emitting point O of the synchrotron radiation source is located on the extended tangential surface of the mirror surface ridge of the synchrotron radiation reflecting mirror 1 having a cylindrical concave reflecting surface. A circle centered on the light emitting point O is drawn with the length of the perpendicular line OC drawn from the center as a radius, and the emitted light reflecting mirror 1 is swung in a state in which the extended tangential surface of the mirror surface ridgeline is in contact with the circumference of the circle. The gist of this is that we have made it possible.

[0011]

[Operation] In both of the configurations of the above two inventions, the swing of the synchrotron radiation reflecting mirror 1 is such that the distance from the light source emission point O to the extended tangent surface of the mirror surface ridge is constant (OC), and the swing of the mirror The accompanying change in the degree of convergence of the synchrotron radiation no longer occurs. Therefore, by arbitrarily setting the length of this OC in relation to the radius of curvature R of the mirror 1, the reflected X-rays can be adjusted to be parallel, condensed, or divergent.

0012

DESCRIPTION OF THE PREFERRED EMBODIMENTS Specific embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 3 shows a portion of the radiation reflection mirror 1 provided in the beam lines 18a and 18b in the X-ray exposure apparatus of the first invention of the present application, and FIG. 4 shows a side view thereof,
Further, FIG. 5 shows a side sectional view thereof.

In this embodiment, a synchrotron radiation reflecting mirror 1, which will be described later, is fixed in the middle of beam lines 18a and 18b maintained in an ultra-high vacuum for guiding synchrotron radiation from an electron storage ring serving as a light source. A mirror box 11 is provided, and the mirror 1 is made to swing by swinging the entire mirror box 11.

The synchrotron radiation reflecting mirror 1 is composed of a cylindrical concave reflecting surface with a radius of curvature R in order to reflect and bend the synchrotron radiation emitted from the light source while suppressing its horizontal spread. There is.

The mirror box 11 that holds the mirror 1 therein is provided with a pair of leaf springs 12a and 12b on its left and right sides. One end of these leaf springs 12a, 12b that is spaced apart from each other is fixed to the mirror box 11 by a spring fixing fitting 13a, and the other end with a narrower spacing is fixed to the spring support fitting 13b.
It is fixed to the stand 14 by. and leaf spring 1
The extended surfaces of 2a and 12b intersect into one on the narrower side, and the point of intersection becomes the center W of rocking when the mirror 1 is rocked together with the mirror box 11. In this embodiment, this swing center W is set to coincide with the light emitting point O of the light source.

Furthermore, as a structure for swinging the mirror box 11, a motor 15 fixed on the stand 14 is used.
An eccentric force cam 15b is attached to the rotating shaft of the mirror box 11.
The structure is such that they mesh with each other. Therefore, if the eccentric cam 15b converts the rotational motion of the motor 15a into a swinging motion and causes the mirror box 11 to swing by a minute amount, the mirror 1 held inside also moves to the light source light emitting point O (i.e., the swing center W). ) can be slightly oscillated around the center. Furthermore, mirror box 1
1 is connected to beam lines 18a and 18b by flexible bellows 17a and 17b.
, 18b and the mirror box 11 while maintaining the ultra-high vacuum state, the distortion caused by the oscillation is absorbed. Further, on the upper part of the mirror box 11, there are fine adjustment mechanisms 19a and 19 for adjusting and fixing the position of the mirror 1 and the direction of the mirror surface.
b is provided, and by adjusting the inclination of the mirror surface by these mechanisms 19a and 19b, the distance between the extended tangent surface of the mirror surface ridge line and the light source emission point O (that is, corresponds to the above-mentioned OC)
is adjusted. In this embodiment, the fine adjustment mechanisms 19a, 19
By adjusting the inclination of the mirror surface using b, the distance (
OC) is set, so that the emitted light reflected by the mirror 1 becomes parallel light in the horizontal direction and is irradiated onto the mask and wafer resist surface.

In the device configuration as described above, the motor 15a
By rotating the mirror box 11 and slightly swinging the entire mirror box 11, the synchrotron radiation reflecting mirror 1 fixed inside swings with the light source emission point O as the swing center W, and the synchrotron radiation is directed vertically. can be scanned. In this way, since the center of oscillation W coincides with the light source light emitting point O, the distance between the extended tangential surface of the mirror surface ridgeline and the light emitting point O does not change, and therefore synchrotron radiation as shown in FIG. The degree of horizontal convergence of light does not change even when the mirror 1 scans (the range indicated by X in the figure is the required exposure range, and the range indicated by Y is the irradiation range). be).

[0019]

As described in detail above, according to the X-ray exposure apparatus of the present invention, the synchrotron radiation is focused by the synchrotron radiation reflecting mirror having a cylindrical concave reflecting surface, and the synchrotron radiation is oscillated. When a device configuration is adopted in which the irradiation area of the synchrotron radiation is expanded by increasing the irradiation area, the synchrotron radiation reflecting mirror is set so that the distance from the light emitting point of the light source to the extension tangent surface of the mirror surface ridgeline is always constant. Since the mirror is oscillated, the degree of horizontal convergence of the reflected synchrotron radiation light does not change due to the oscillation of the mirror, and the irradiation range, illuminance, and illuminance unevenness can be kept approximately constant. . Therefore, X with respect to the swing angle of the emitted light reflecting mirror
Since the scan speed of the mirror can be controlled by mainly considering the wavelength dependence of the line, the control becomes easy.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing the basic configuration of the present invention.

FIG. 2 is an explanatory diagram showing the basic configuration of the second invention.

FIG. 3 is a perspective view showing the configuration of an apparatus according to an embodiment of the first invention.

FIG. 4 is a side view of the configuration of this embodiment.

FIG. 5 is a side sectional view of the configuration of this embodiment.

FIG. 6 is an explanatory diagram of an irradiation example showing a state in which there is no change in the degree of convergence of emitted light due to the configuration of this embodiment.

FIG. 7 is an explanatory diagram showing a conventional X-ray exposure configuration using synchrotron radiation.

FIG. 8 is an explanatory diagram of an irradiation example showing a state in which the degree of convergence of emitted light is changed by this conventional configuration.

FIG. 9 is an explanatory diagram showing a state in which light is focused by a mirror having a cylindrical concave reflecting surface.

FIG. 10 is an explanatory diagram showing a state in which light is focused by a mirror having a cylindrical concave reflecting surface.

FIG. 11 is an explanatory diagram showing the scanning state of the emitted light when a emitted light reflecting mirror having a cylindrical concave reflecting surface in a conventional configuration is oscillated.

FIG. 12 is an explanatory diagram showing a state of synchrotron radiation scanning according to the conventional configuration.

[Explanation of symbols]

1 Radiant light reflecting mirror 10 Reflection mirror 11 Mirror box 12a, 12b leaf spring 18a, 18b beam line O Luminous point W Swing center R Radius of curvature

Claims (2)

[Claims] Claim 1: An X-ray device that condenses synchrotron radiation emitted from a light source and expands the irradiation area on a group of plate-shaped objects to be exposed by swinging a radiation reflection mirror having a cylindrical concave reflecting surface. An X-ray exposure apparatus characterized in that the center of oscillation of the synchrotron radiation reflecting mirror is made to coincide with the light emitting point of the synchrotron radiation source. Claim 2: An X-ray device that condenses synchrotron radiation emitted from a light source and expands the irradiation area for a group of plate-like objects to be exposed by swinging a radiation reflection mirror having a cylindrical concave reflecting surface. In the exposure apparatus, a circle centered at the light emitting point is drawn with the length of the perpendicular drawn from the light emitting point of the synchrotron radiation light source onto the extended tangential surface of the mirror surface ridge of the synchrotron radiation reflecting mirror as a radius, and a circle is drawn on the circumference of the light emitting point. An X-ray exposure apparatus characterized in that the emitted light reflecting mirror is able to swing in a state in which an extended tangent surface of the mirror surface ridgeline is in contact with the extended tangent surface.