JPS6030132A - Photolithography device - Google Patents

Abstract

PURPOSE:To eliminate the effect of dust by a masking mechanism while minimizing the quantity of gradation on a wafer through optical technique by adding a blade focus optical system to an exposure optical system for an exposure light source and providing the masking mechanism into the blade focus optical system. CONSTITUTION:A blade focus optical system 16 is added to a conventional exposure optical system in an exposure light source 15, and a masking mechanism 18 is mounted where a blade 19 images on the surface of an original picture 10. The blade 19 is fitted at a position optically conjugated to the position of the original picture 10 to the wafer 12. Consequently, the conventional exposure optical system is changed into an optical system in which the calescence point of an extra-high pressure mercury lamp 2 is imaged onto an entrance pupil in a reducing glass 11 in a conventional manner and the blade 19 is imaged onto the surface of the original picture 10. The masking mechanism 18 consists of four blades 23, 24, 35, 36 each driven independently in the X direction and the Y direction, the opening and closing of the X blades 23, 24 are controlled by X blade driving motors 29, 30, the opening and closing of the blades in the Y direction are also controlled similarly, thus masking the desired section of the surface of the original picture 10 from the four directions.

Description

[Detailed description of the invention] [Field of application of the invention] The present invention relates to photolithography apparatus.

[Background of the invention]

In conventional photolithography, as shown in FIG. 1, a masking mechanism 8 is installed above the original image 10 to mask the entire desired portion of the original image using one or more blades (hereinafter referred to as blades).

That is, an ultra-high pressure mercury lamp 2, a condensing mirror 3, a plane mirror 4,
Mixer lens group 5, plane mirror 6, and condenser lens group -Ah is projected onto the wafer 12 through the reduction lens 11. Note that the wafer 1
2 is placed on the XYZ stage 13 on the device base 14.

In such an apparatus, in order to minimize the amount of mask edge blur of the original image 10 projected onto the wafer 12, the blade 9
Ideally, the blade should be in close contact with the original image 10, but since there is a pellicle film for preventing dust adhesion and mechanical parts other than the masking mechanism near the original image 10, the blade 9 should not be close to the original image lO. There was a limit to what I could do. Therefore, blade 9
A gap was created between the original image 10 and the original image 10, and the edge of the mask (edge end of the blade 9) of the original image 10 projected onto the wafer 12 was blurred to some extent.

In addition, the masking mechanism 8
Since the mechanical parts of the image forming apparatus were moved, a serious problem occurred in terms of dust adhesion to the original image 10.

[Purpose of the invention]

The purpose of the present invention is to prevent a drop in wafer yield due to dust shadow transfer by minimizing dust adhesion on the original image, which can be a fatal damage to photolithography equipment, and at the same time reduce the amount of blur on the wafer when masking the original image with a blade. It is an object of the present invention to provide a photophosphorography device that can increase the exposed area by minimizing the area and efficiently utilize the chip area on a wafer.

[Summary of the invention]

The present invention adds a blade focus optical system to the exposure optical system of the exposure light source and provides a masking mechanism within the blade focus optical system, thereby separating the masking mechanism from above the original screen to completely eliminate the influence of dust caused by the mechanism. The amount of blur on the wafer is minimized by closely masking the original screen using an optical method.

[Embodiments of the invention]

The present invention will be explained in detail below using examples.

FIG. 2 is a block diagram showing an embodiment of a photolithography apparatus according to the present invention. In the figure, an exposure light source 15 with a built-in masking mechanism 18, a reduction lens 11 for reducing and projecting an original image 1O having a pattern to be transferred onto a wafer 12 and the original image 10, and a reduction lens 11 for transporting the wafer 12 to an exposure position and reducing it. X to position the focal position of the lens 11
It consists of a YZ stage 13 and a base 14 of the device, which serves as a reference to which a few of these elements are attached.

Inside the exposure light source 15, there is an ultra-high pressure mercury lamp. This light is collected by a condenser mirror 3 with an elliptical cross section, and the direction is changed by a plane mirror 4. After that, it is made uniform by a mixer lens group 5, and the direction is changed again by a plane mirror 6, and then a condenser lens is used. A blade focus optical system 1 is added to the conventional exposure optical system that collects the original image at 7 and then projects it onto the original image plane.
6 is added, and a masking mechanism 18 is provided at a position where the blade 19 forms an image on the original image 10.

The blade focus optical system 16 includes a plurality of lenses (focus lens group 17) and a mixer lens group 20. It is located between the focus lens group 17 and the mixer lens 200.

A blade 19 is provided at a position optically conjugate with the position of the original image lO with respect to the wafer 12. Accordingly, the conventional exposure optical system that enlarges and images the bright spot of the ultra-high-pressure mercury film 2 on the mixer lens group 5 and then forms the image on the entrance pupil of the reduction lens 11, The conventional optical system is changed to one in which the bright spot of the lamp 2 is imaged onto the entrance pupil of the reduction lens 11, and the blade 19 is imaged onto the original image 10.

FIG. 3 shows a perspective view of the masking mechanism 18, and FIG. 4 shows a partially detailed view. The masking mechanism 18 has four blades 23, 24, and 35 each independently driven in the X and Y directions.
．． It consists of 36. X direction mask 21 and Y direction mask 33
is composed of the same elements and is the base of each mask
The frame 22 and the X frame 34 are fixed to the framework of the exposure light source 15 with a built-in masking mechanism.

The X frame 22 has a hollow structure, and the X blade 23 and the X blade 24 slide on the hollow part. At the four corners of the X frame 22 are an X blade drive wheel 25, an X blade drive wheel 26, an X rolling wheel, 27.2
8 are provided, and each drive wheel 25,26 is driven by an independent drive motor 29,30. The X-blade drive wheel 25 is made up of an X-blade drive row 245 fixed to the motor shaft of the X-blade drive motor 29 and an X-blade drive roller 46 that freely rotates around the motor shaft. It consists of an X-blade drive roller 48 fixed to the motor shaft of the blade drive motor 30 and an X-blade rolling roller 47 that rotates freely around the motor shaft.

The shafts of each motor 29, 30 have a step (not shown), and on this step, an X blade drive roller 45 is attached in the case of the
The grade rolling roller 47 has an X-blade transfer roller 46 and an X-blade drive row 248 attached therebelow, and its lowermost end is fixed with a collar 49. Also, X rolling wheel 27
．． Each of the rollers 28 consists of two freely rotating transfer rollers, upper and lower. Endless X-grade drive wires 31 and X-blade drive wires 32 are fitted into two upper and lower loans at the four corners of the X-frame 22, respectively, and the X-blade drive wire 31 is connected to a pin 50 screwed into the X-grade 23.
The rotation of the motor is transmitted by the X-blade drive roller 45 which is glued and fixed to the motor shaft of the X-blade drive motor 29 and screwed to the motor shaft of the X-blade drive motor 29, causing the X-blade 23 to slide within the hollow portion of the ing. X
The blade drive wire 32 is configured to slide the X blade 24 within the hollow portion of the X frame 22 in the same manner as the X blade drive wire 31. By controlling the rotation of the X-blade drive motor 29 and the X-blade drive motor 30 as described above, the X-blade 23 and the X-blade 24 are
It becomes possible to control the opening and closing of

The Y-direction mask 33 is completely similar to the aforementioned X-direction mask 21, and with these, desired portions of the original image 10 can be masked freely from four directions.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, it is possible to suppress dust adhesion on an original image, and it is possible to suppress the amount of blur on the vine when masking the original image with a blade.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an example of a conventional photolithography device, FIG. 2 is a block diagram illustrating an embodiment of a photolithography device (d) according to the present invention, and FIG. 3 is a part of the above embodiment. A fourth perspective view showing the appearance of the masking mechanism.
The figure is a detailed perspective view of a portion of FIG. 1... Exposure light source, 2... Ultra-high pressure mercury lamp, 3...
・Concentrator mirror, 4...Plane mirror (1), 5...Mixer lens group (18) 6...Plane mirror (2), ?...Kopfusa lens, 1O...Original picture, 11...Reduction S/Z,
12... Wafer, 13... XYZ stage, 14...
...Device pace, 15...Exposure light source with built-in masking mechanism, 16...Blade focus optical system, 17...
Focus lens group, 18...masking mechanism (2)
, 20... Mixer lens group (2), 21... Go
Country I No. 3 Figure 1

Claims (1)

[Claims] 1. In a photophosphorography device that optically projects and exposes an original image onto a resist-coated wafer, a position optically conjugate to the position of the original image with respect to the wafer is created inside the exposure light source, and the original image is placed at that conjugate position. 1. A photolithography apparatus characterized in that a masking element is provided to enable masking on a wafer.