JPS6038819A - Projecting and exposing device - Google Patents

Abstract

PURPOSE:To obtain the projecting and exposing device with which a refrection mirror can be maintained in high degree of mirror face accuracy even after an assembling work has been finished and that a mask pattern can be image-formed on a wafer with a high degree of resolution. CONSTITUTION:A concave mirror 5 is disc-shaped and it is thick at the edge part and thin in the center part, and it is arranged on the inner circumferential part of a ring- shaped frame body which is used as a supporting means. At a plurality of places on the inner circumferential side face of said concave mirror 5 which is mentioned below, a groove 20 is provided and a bank part 21 is formed between the groove 20 and the back side of the concave mirror 5. Said concave mirror 5 is arranged at the prescribed position of the frame body 23 before a block 24 is inserted. Subsequently, the block 24 is inserted, and it is fitted to the groove 20 of the concave mirror 5. As the bulge of the block 24 is pressure-welded to the metal snap 22 of the bank part 21, the bank part 21 is pinched between the block 24 and another block 26. Also, as the bolt 27 to be used for adjustment which is screwed into the screw hole is contacted to the metal snap located at the bottom of the groove 20, the concave mirror 5 is fixed to the circumferential direction, and it is supported by the frame body 23.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a projection exposure apparatus that images a mask pattern onto a wafer with high resolution.In particular, the present invention relates to a projection exposure apparatus that forms an image of a mask pattern on a wafer with high resolution. Pertains to.

[Background of the invention]

Conventionally, projection exposure equipment whose optical system consists of reflecting mirrors
The problem was that the resolution of the image was dependent on the accuracy of the intermediate reflecting mirror surface. FIG. 1 is a schematic configuration diagram showing an example of a reflection projection exposure apparatus. In the figure, a reflection projection exposure device 3
is a concave mirror 5 and a convex mirror 6 as reflecting mirrors inside the frame 9.
, and three plane mirrors 7'i are arranged.

The ultraviolet rays emitted from the light source device 1 pass through the mask 2, and then the optical path is refracted by the five reflecting mirrors, and an image is formed on the wafer 4 arranged on the same plane as the mask 2. .

Here, in order to image the pattern of the mask 2 on the wafer 4 with high resolution, it is necessary to maintain the precision of the reflecting mirror surface on the way through which the ultraviolet rays pass. For example, assuming the accuracy of the reflective mirror surface is λ=63 buttons 1m, λ/10 to λ/20
However, even if the mirror surface processing technology achieves the above accuracy, the assembly process and installation of the projection exposure equipment may cause distortion depending on the posture and holding method of the reflecting mirror afterwards, and the accuracy may be reduced. will be dropped. In particular, the concave mirror 5 is about 3
It is difficult to maintain accuracy because it is sometimes attached to the frame 9 with a forward tilt of 0 degrees.

That is, a drawback of the conventional reflection projection exposure apparatus is that it is difficult to maintain mirror precision. This will be explained throughout history.

FIGS. 2(α) and 2(b) are a front view and a sectional view showing an example of a concave mirror holding method in a reflection projection exposure apparatus. In both figures, a concave mirror 5 having a medium-thin disk shape is attached to the inner periphery of a ring-shaped frame 8, which is a holding means fixed to the frame of the projection exposure apparatus, through a pad 11, a seat 12, and a screw 13. It is fitted. 11 pins, 1 seat
There are six sets of screws 2 and screws 13, and they are arranged at positions equally dividing the circumference 't-3 of the ring. Since the concave mirror 5 and its frame 8 are attached to the frame 9 at an angle of approximately 30 degrees forward, the presser foot 10 is placed in an arc with respect to the circumferential arc of the frame 8 so that the concave mirror 5 does not come off the frame 8. is fixed. Needless to say, the disadvantage of this method of mounting a concave mirror is that the weight of the concave mirror 5 is applied to the presser foot 10 and the mirror surface is likely to be distorted due to stress. If the screw 13 is tightened too tightly, the concave mirror 5 will be pressed from the side, which will also cause distortion. All of these affect the mirror surface accuracy of the concave mirror 5,
The high accuracy, which was satisfactory during mirror finishing, will be degraded due to several flaws in the method.

[Purpose of the invention]

SUMMARY OF THE INVENTION The present invention aims to provide a projection exposure apparatus that can maintain the mirror surface accuracy of a reflecting mirror at a high level even after the assembly process and image a mask pattern onto a wafer with high resolution, excluding the above-mentioned drawbacks. purpose.

[Summary of the invention]

In order to achieve all of these objectives, the present invention forms a central portion between the back surface of the reflective mirror and the grooves by fully carving grooves at multiple locations on the side surface of the reflective mirror, and also holds the central portion. It is characterized in that the frame body is also provided with all clamping members at positions facing the grooves, and the clamping members clamp the central portion to hold the entire reflecting mirror without affecting the mirror surface.

[Embodiments of the invention]

Hereinafter, one embodiment of the present invention will be described based on the drawings.

FIGS. 3(a) and 3(b) are a front view and a sectional view schematically showing an example of a concave mirror holding method according to the present invention. In the figure, the concave mirror 5 has a disk shape with a medium-thin edge thickness, and is arranged on the inner circumference of a ring-shaped frame 5 that is a holding means. Grooves 2 are provided at multiple locations on the circumferential side of the concave mirror 50, which will be described later.
0 is carved in the center part 2 between the groove 20 and the back surface of the concave mirror 5.
1 is formed. The positions of the grooves 20 are at intervals that equally divide the circumference into three, and are at positions that form a chord with respect to the arc of the circumference. On the other hand, on the inner peripheral side of the frame body 23, a block 24t as one of the clamping members is protruded and engaged with the groove 20 at a position facing the groove 20 and the central portion 21. Furthermore,
A wall portion is integrally formed on the inner edge of the frame side of the frame body 23, that is, on the back side of the concave mirror, and a piece 26 disposed on this wall portion as another holding member is biased by a spring to hold the concave mirror. The concave mirror 5t is held in the frame 23 without affecting the mirror surface by being pressed against the back surface of the concave mirror 5t and sandwiched between the round part 21t and the block 24. In addition, the part where the piece 26 and the central part 21 touch, the central part 21 and the block 2
4, and the part where the block 24 and the groove 2 are in contact with each other.
A pad 22 is attached to the concave mirror 5 at a portion where the concave mirror 5 contacts the bottom surface of the concave mirror 5.

Next, this embodiment will be explained in more detail.

FIG. 4 (αL (b) is a sectional view showing in detail the entire history of the concave mirror holding means of this embodiment. In the figure, the block 24 is inserted from the outer peripheral side of the frame 23. , its tail is formed in an arc shape that matches the outer periphery of the frame 25, and is positioned and screwed to the frame 23 by the tail.

The top of the block 24 is an irises-shaped plate having a bulge on the frame side, and the main screw hole passes through the central bulge in the insertion direction of the block 24.

The concave mirror 5 is placed at a predetermined position on the frame 23 before the block 24 is inserted, and then the block 24 is inserted and fitted into the groove 20 of the concave mirror 5. Since the bulge of the block 24 is in pressure contact with the pad 22 of the photographing section 21, the photographing section 21 is connected to the block 24 and the frame 2.
Also, since the adjustment port 27 screwed into the main screw hole is in contact with the stopper 22 on the bottom of the groove 20, the concave mirror 5 It is also fixed in the circumferential direction and held by the frame 23.

Next, as another embodiment of the present invention, a method for attaching a flat reflecting mirror will be described.

FIG. 5 is a front view and a sectional view showing an example of a conventional plane mirror holding method. In the figure, a plane mirror 7 is fixed with an adhesive 32 to a plate-shaped holding base 31, which is a holding means that extends like a perch between side frames of the projection exposure apparatus. However, the usage of the adhesive 32 is not an adhesive type, but
A hole 33 is provided in the plate surface of the holding base 51, and the inner surface of the hole 35 and the back surface of the plane mirror 7 are filled with gold adhesive 32.
The adhesive 32 is not necessarily applied uniformly, and there is a risk that it may affect the mirror surface as it hardens.The present invention is also applicable to the installation of such flat mirrors. It is possible.

FIG. 6 is a sectional view showing an example of a method for holding a plane mirror according to the present invention. In the figure, the plane mirror 7 is a thick rectangular plate material, with grooves 64 carved in three places at both ends of the upper side and at the center of the lower side, and a round part 65 entirely formed between the back side and the grooves. . On the other hand, holding stands 57VC, which are holding means, have a normal plate shape and are stretched between the side frames. Then, it is inserted into the groove 54 of the plane mirror 7, and the plane mirror 7 is fully grasped. In these three, screw holes are connected in a plate surface corresponding to the photographing section 35 of the holding table 37, and a push screw 3 is screwed into the screw hole.
9 and the hook! +8 serves as a clamping member to clamp the plate portion 55i, and a holding base 37 as a holding means holds the plane mirror 7 without casting a shadow on the mirror surface. Note that the plane mirror 7 (
/C pad 36 is installed.

In any of the above cases, the photographing section is formed by stamping St on the side surface of the book and the reflecting mirror, and the photographing section is held between the clamping members and the reflecting mirror is fixed to the holding means, so that the stress is reduced to the photographing section. It only affects the mirror surface, and has no effect on the mirror surface. Also, in this example.

Although the photographing section is formed by a groove, it is also possible to form the entire protrusion by processing the side surface and hold the protrusion.

〔Effect of the invention〕

As explained above, according to the present invention, the entire camera part is formed by creating W# at a plurality of locations on the side surface of the reflecting mirror, and the photographing part is held by the holding member provided in the holding means. By fixing the reflecting mirror to the holding means without applying stress to the mirror surface of the reflecting mirror, it is possible to maintain high surface accuracy during mirror finishing even after the assembly process, and the pattern of the mask can be improved. By forming an image on a wafer with high resolution, it will have a great effect on increasing the density and fine patterning of future semiconductor products.

In addition, as a by-product of the above effects, there is an economical effect of improving product yield, and it also eliminates the need to pay excessive force to prevent distortion during the assembly process, contributing to easier assembly and faster work. It turns out.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram of a projection exposure apparatus, Fig. 2 shows an example of a conventional concave mirror holding method, (α) is a front view thereof, (A) is a sectional view thereof, and Fig. 3 is a cross-sectional view. Fig. 4 shows an example of a concave mirror holding method according to the present invention; Fig. 3 (α) is a front view thereof, Fig.
), and Figure 4 (α) is a partial enlarged view of Figure 6 (-).
4(h) is a sectional view taken along the line E-E in FIG. 4(cL), FIG. 5 shows an example of a conventional plane mirror holding method, and FIG. , the same figure (b) is the same figure (α)
6 shows an example of the plane mirror holding method according to the present invention. FIG. 6 (α) is a partially sectional side view, and FIG. It is a sectional view taken along the line DD. 1... Light source device 2... Mask 3... Reflection projection exposure device 4... Wafer 5... Concave mirror 6... Convex mirror 7... Plane mirror 8... Frame 9... Frame 1o...Press 11...Batch 12...Seat 13...Press screw 2o...Groove 21...Plate part 22...Batch 23...Frame body 24...・Block 25... Spring 26... Piece 27... Bonito 31b and 67... Holding stand 34
...Groove 35...Plate part 36...Ball 38...Hook 39...Press screw whisper 1 Figure exposed? 7 Koma 3 figure (α) (b) A'' 4 figure foil S figure ((IL) (b)

Claims (1)

[Claims] In a projection exposure apparatus that refracts the ultraviolet light that has passed through the mask pattern by one or more reflecting mirrors attached to a holding means and forms an image on the wafer, grooves are carved in multiple places on the side surface of the reflecting mirror. By doing so, a photographing section is formed between the back surface of the reflecting mirror and the above-mentioned box, and the holding means is provided with a plurality of pairs of clamping members corresponding to the photographing section, and these clamping members are used to hold the photographing section. A projection exposure device characterized in that a reflecting mirror is entirely held by holding it in place.