JP2005045095A - Manufacturing method of optical space modulation element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of an optical space modulation element capable of proper transfer exposure even for a chip pattern in the vicinity of an edge of a wafer, and increasing the number of times of chip transfer. <P>SOLUTION: The pattern A of a chip pattern 1 located in the vicinity of the edge 41a of a wafer 41 and the pattern C of a chip pattern 2 located in the vicinity of an edge 41b existent at a diagonal position on the wafer 41 are transferred. Thereupon, a mask 2 is used to transfer the patterns A, C, and the position of an optical axis 10 is located within the range of the wafer 41. Consequently, the transfer is achieved in the state where the leveling focusing information is obtained. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method for manufacturing a spatial light modulation element, and in particular, in the case where a semiconductor device chip including a plurality of identical patterns is transferred onto a wafer by photolithography, the exposure conditions for transferring each pattern are equalized. Also, it relates to an improvement for increasing the number of transferred chips.

  A semiconductor device, which is a light spatial modulation element applied to a liquid crystal image display device, has a number of identical patterns arranged continuously and repeatedly in its circuit configuration.

  In general, since such a semiconductor device is a large-area chip, it is impossible to fit the entire chip in a single mask.

  Therefore, when manufacturing a semiconductor device as described above by photolithography, a circuit that is repeated as the same pattern is formed on the mask as a single representative pattern. A method is adopted in which a single mask is arranged and formed in a concentrated manner, and a repeated pattern is efficiently exposed and transferred using the mask.

  In addition, various proposals have been made in the following Patent Documents 1 and 2 regarding a method for manufacturing a semiconductor device based on this method.

  In a spatial light modulation element applied to a liquid crystal image display device, a pixel number matrix for displaying a pixel electrode for optically modulating an image as one unit is arranged, and a circuit for driving the pixel electrode sandwiches the pixel electrode. The arrangement is common. Therefore, in the exposure transfer method described above, for example, one chip of a semiconductor device formed on a wafer is a chip pattern 1 composed of a combination of circuit patterns as shown in FIG. When B1 to B5 and C are the same patterns A, B and C, respectively, a single mask 3 in which the patterns A, B and C are collectively arranged and formed as shown in FIG. 5B is used. . This is because the overall exposure time can be reduced by reducing the number of exposures, which is efficient.

  In FIG. 5B, 20 is the center of the mask 2.

  In many cases, a reduction projection exposure apparatus as shown in FIG. 6 is used as the exposure apparatus. In this case, the mask 3 is a reticle mask.

  In the figure, reference numeral 31 denotes an exposure light source, and light emitted from the exposure light source is irradiated onto the mask 3 via a flyan lens 32, an aperture 33, a condenser lens 34, a mirror 35, and a condenser lens 36.

  Further, the optical axis 10 of the exposure light beam irradiated from the mirror 35 to the mask 3 side through the condenser lens 36 is set so as to pass through the center 20 of the mask 3 fixed to the installation table 30.

  A blind 37 is provided on the upper side of the mask 3 so that the blind drive unit 38 shields areas other than the pattern to be transferred among the patterns A, B, and C of the mask 3. .

  The light transmitted through the pattern of the mask 3 opened by the bride 37 is condensed on the wafer 41 installed on the upper surface of the leveling stage 40 via the projection lens 39, whereby the pattern of the mask 3 is converted into the wafer 41. Is projected and transferred.

  The leveling stage 40 is mounted on a Z stage 42, and the Z stage 42 is mounted on an XY stage 43.

  Then, the wafers based on the intersection of the wafer 41 and the optical axis 10 are respectively referred to by the two optical systems composed of the LEDs 44 and 45, the collimating lenses 46 and 47, the condenser lenses 48 and 49, and the photodetectors 50 and 51. 41, the leveling information and the focus information regarding a certain area are obtained, and the information detected by the photodetectors 50 and 51 is input to the main control unit 52, and the main control unit 52 is based on the information. By controlling the leveling drive unit 53 and the Z drive unit 54, the tilt angle of the wafer 41 and the position in the optical axis direction (focus position) are adjusted so that proper transfer exposure is always performed.

  In addition, the main control unit 52 has a work program created based on the arrangement conditions related to the patterns A, B, and C of the chip pattern 1 and the mask 3 of the semiconductor device and the arrangement conditions of the chip pattern 1 on the wafer 41. It is set in advance.

The main control unit 52 reads the program and controls the XY drive unit 55 to move the XY stage 43 in the horizontal direction, thereby controlling the shielding state of the blind 37 and the leveling / focusing. While controlling the leveling stage 40 and the Z stage 42 according to the information, each pattern A, B, C of the mask 3 is selectively transferred to the set position of the wafer 41 and finally a large number of chip patterns 1 are formed on the wafer 41. Let it form.
Japanese Patent Laid-Open No. 10-73916 JP 2000-323389 A

  By the way, the spatial resolution modulator applied to the liquid crystal image display device has been improved in resolution, and accordingly, the size of the element is increased and the facing direction becomes more than 1 inch. Conventional mask patterns are arranged to increase the exposure positioning and exposure efficiency in the exposure equipment, but the size of the chip of the semiconductor device has increased, so that the peripheral part on the wafer can be used efficiently and one wafer. Therefore, exposure so that more chips can be arranged affects the yield.

  Therefore, assuming that the chip patterns 1a and 1b arranged near the edge of the wafer 41 are transferred by the patterns A, B, and C of the mask 3, as shown in FIG. The region in which the pattern C in 1b is to be formed is closest to the edge 41b of the wafer 41, but this 41b side is not a problem. However, at the edge 41a of the wafer 41 on the opposite side, the area where the pattern A in the chip pattern 1a is to be formed is closest to the edge 41a of the wafer 41. In this case, the optical axis 10 is located outside the wafer 41. In this state, leveling / focus information cannot be obtained.

  Therefore, if the transfer is executed as it is, a pattern short circuit or the like due to defocusing occurs, and depending on the exposure apparatus, such a transfer may be disabled. As a result, the chip pattern 1a is formed in a region close to the edge 41a. This makes it impossible to reduce the number of transferred chips, resulting in poor yield.

  In the pattern of the mask 3, even if the arrangement of B, A, and C is reversed, only the position where the leveling / focus information cannot be obtained is changed, and the problem that the yield is deteriorated cannot be solved.

  The present invention has been made in view of the above points, and devised a mask used when transferring a semiconductor device chip of a light spatial modulation element applied to a liquid crystal image display device including a plurality of identical patterns onto a wafer. Accordingly, an object of the present invention is to provide a method of manufacturing an optical spatial modulation element that can reasonably solve the above problems.

In order to solve the above problems, the present invention comprises the following means.
That is,
The optical axis of the exposure light beam is set so as to pass through the center of the mask, and the optical system is different from the exposure light beam based on the focus leveling information obtained with reference to the intersection point of the optical axis and the wafer. An exposure apparatus that transfers each pattern of the semiconductor device formed on the mask to the wafer while controlling the position and angle of the wafer in the optical axis direction, and includes a plurality of different patterns. In the manufacturing method of the spatial light modulator for transferring the chip onto the wafer,
Preparing a mask in which a plurality of identical patterns for each different pattern in the semiconductor device are arranged and formed on a mask as a single representative pattern,
The representative pattern is arranged in a positional relationship in the arrangement of the plurality of different patterns,
When the formation regions of the same pattern of the semiconductor device to be formed on the wafer are aligned adjacent to each other, the center of the mask is to be formed on the wafer when viewed from the optical axis direction. A method of manufacturing a spatial light modulation element, wherein transfer is performed using the mask so as to be located in a region where the same pattern is formed.

  According to the “method of manufacturing a spatial light modulating element” of the present invention, it is possible to obtain focus / leveling information from the wafer surface even for a pattern formed in the vicinity of the edge of the wafer. Appropriate transfer exposure is possible even for a chip pattern near the edge of the wafer, which has been possible, and an increase in the number of chip transfers is realized.

  The best mode for carrying out the invention of the method for manufacturing a spatial light modulator according to the present invention will be described below with reference to preferred embodiments. However, also in this embodiment, a case where a large number of chip patterns 1 shown in FIG. 2A are transferred onto the wafer 41 shown in FIG. 1 using the exposure apparatus shown in FIG. 6 will be described as an example.

  In FIG. 6, reference numeral 31 denotes an exposure light source, and light emitted from the exposure light source is irradiated onto the mask 2 through a fly-an lens 32, an aperture 33, a condenser lens 34, a mirror 35, and a condenser lens 36.

  Further, the optical axis 10 of the exposure light beam irradiated from the mirror 35 to the mask 2 side through the condenser lens 36 is set so as to pass through the center 20 of the mask 2 fixed to the installation table.

  A blind 37 is provided on the upper side of the mask 2 so that a blind drive unit 38 shields an area other than the pattern to be transferred among the patterns A, B, and C of the mask 2. .

  The light transmitted through the pattern of the mask 2 opened by the bride 37 is condensed on the wafer 41 installed on the upper surface of the leveling stage 40 via the projection lens 39, whereby the pattern of the mask 2 is converted into the wafer 41. Is projected and transferred.

  The leveling stage 40 is mounted on a Z stage 42, and the Z stage 42 is mounted on an XY stage 43.

  Then, the wafers based on the intersection of the wafer 41 and the optical axis 10 are respectively referred to by the two optical systems composed of the LEDs 44 and 45, the collimating lenses 46 and 47, the condenser lenses 48 and 49, and the photodetectors 50 and 51. 41, the leveling information and the focus information regarding a certain area are obtained, and the information detected by the photodetectors 50 and 51 is input to the main control unit 52, and the main control unit 52 is based on the information. By controlling the leveling drive unit 53 and the Z drive unit 54, the tilt angle of the wafer 41 and the position in the optical axis direction (focus position) are adjusted so that proper transfer exposure is always performed.

  In addition, the main control unit 52 has a work program created based on the arrangement conditions related to the patterns A, B, and C of the chip pattern 1 and the mask 2 of the semiconductor device and the arrangement conditions of the chip pattern 1 on the wafer 41. It is set in advance.

  The main control unit 52 reads the program and controls the XY drive unit 55 to move the XY stage 43 in the horizontal direction, thereby controlling the shielding state of the blind 37 and the leveling / focusing. While controlling the leveling stage 40 and the Z stage 42 according to the information, each pattern A, B, C of the mask 2 is selectively transferred to the setting position of the wafer 41 and finally a large number of chip patterns 1 are formed on the wafer 41. Let it form.

  First, as shown in FIG. 1, the chip pattern 1 which is one unit of the spatial light modulator is arranged on the wafer 41 as efficiently as possible. As shown in FIG. 2A, one unit of the spatial light modulating element is arranged in a matrix of pixel numbers displayed by pixel electrodes for light-modulating the picked-up image, B1 to B5, and circuits A and C for driving the pixel electrodes. Are arranged across the pixel electrode.

  FIG. 2B is a plan view of the mask 2 used in this embodiment. The mask in FIG. 2B corresponds to the mask 3 in FIG. 5B described in the prior art, and the arrangement of patterns A, B, and C. The region is set at a position in accordance with the arrangement of the chip pattern 1.

  Assume that the patterns B1 to B5 in the chip pattern 1 of FIG.

  The optical positional relationship between the chip pattern 1 and the mask 2 in that case is shown in FIG. 3. When the pattern B of the mask 2 is made to correspond to the pattern B1 of the chip pattern 1, the optical axis 10 of the exposure apparatus is the mask of the chip pattern 1. The leveling focus information is obtained from the area where the same pattern is to be formed.

  Next, when transferring the patterns B2 to B5 of the chip pattern 1, the pattern B of the mask 2 is applied in the same manner as described above. The optical axis 10 of the exposure apparatus in these cases is located in the formation area of the patterns B2 to B5 of the chip pattern 1 in each case, and the leveling / focus information is obtained from the area where the same pattern is to be formed.

  When transferring the patterns A and C of the chip pattern 1, the patterns A and C of the mask 2 are applied as described above. The optical axis 10 of the exposure apparatus in these cases is located in the formation area of the patterns A and C of the chip pattern 1 in each case, and the leveling / focus information is obtained from the area where the same pattern is to be formed.

  As described above, in the semiconductor process, the chip pattern of the semiconductor device is transferred while being arranged in a matrix on the wafer. Accordingly, with respect to the chip pattern 1, as shown in FIG. 1, the chip pattern 1 is repeated in a manner that is closely in the vertical and horizontal directions.

  When the conventional mask 3 is used, the problem with the pattern A is that, as described with reference to FIG. 7, when the chip pattern 1 is arranged in a matrix on the wafer 41, it is near the edge 41a of the wafer 41. The pattern A of the chip pattern 1a to be formed is very close to the edge 41a, leveling / focus information cannot be obtained, pattern short-circuiting due to defocusing, etc. occurs, resulting in a decrease in the number of chip transfers. .

  With respect to this problem, in this embodiment, as shown in FIG. 2, a mask 2 is prepared in which the formation areas of the patterns A, B, and C are arranged in the same order relationship as the arrangement of the chip pattern 1. By using this mask 2, it can be rationally solved.

  That is, since the mask 3 is used in FIG. 7, the center 20 (position of the optical axis 10) of the mask 3 is positioned on the wafer 41 when the pattern A of the chip pattern 1 a near the edge 41 a of the wafer 41 is transferred. Although it was out of range and leveling / focus information could not be obtained, as shown in FIG. 4, when pattern A is transferred using mask 2, the position of optical axis 10 is within the range of wafer 41. Therefore, leveling / focus information can be obtained and transferred.

  Further, as shown in FIG. 4, with respect to the pattern C of the edge 41b at a diagonal position on the wafer 41 with respect to the chip pattern 1b, if the pattern C is transferred using the mask 2, the same as described above. In addition, the position of the optical axis 10 is within the range of the wafer 41, and transfer can be performed with the leveling / focus information obtained.

  Therefore, when the mask 2 is used, the optical axis 10 is located in the formation area of the patterns A and C at any edge 41a, 41b of the wafer 41, and the leveling focus obtained with reference to the center of the formation area. Since the transfer can be carried out as it is based on the information, the problem related to the conventional mask 3 does not occur.

It is a top view which shows the mutual relationship of the chip pattern arrange | positioned on a wafer at matrix form. It is an arrangement example of a chip pattern and a mask applied to the present embodiment. It is a top view which shows the optical positional relationship of a mask and a chip pattern in the case of transferring the pattern B in a chip pattern using the mask of FIG. 2 (B). A pattern A (a pattern closest to the edge of the wafer) in the chip pattern disposed at the left corner of the wafer and a pattern C (a pattern closest to the edge of the wafer) in the chip pattern disposed at the right corner of the wafer are illustrated. It is a top view which shows the optical positional relationship of the mask in the case of transferring with the mask of 2 (B), a chip pattern, and the edge of a wafer. It is an arrangement example of a chip pattern and a mask in a conventional example. It is a system block diagram of exposure apparatus. A pattern A (a pattern closest to the edge of the wafer) in the chip pattern disposed at the left corner of the wafer and a pattern C (a pattern closest to the edge of the wafer) in the chip pattern disposed at the right corner of the wafer are illustrated. It is a top view which shows the optical positional relationship of the mask in the case of transferring with the mask of 5 (B), a chip pattern, and the edge of a wafer.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 1a, 1b ... Chip pattern, 2, 3 ... Mask, 10 ... Optical axis, 20 ... Center of mask, 30 ... Installation stand, 31 ... Exposure light source, 32 ... Fly'an lens, 33 ... Aperture, 34, 36 Condenser lens, 35 ... Mirror, 37 ... Blind, 38 ... Blind drive, 39 ... Projection lens, 40 ... Leveling stage, 41 ... Wafer, 41a, 41b ... Wafer edge, 42 ... Z stage, 43 ... XY stage 44, 45 ... LED, 46, 47 ... collimating lens, 48, 49 ... condensing lens, 50, 51 ... photodetector, 52 ... main control unit, 53 ... leveling drive unit, 54 ... Z drive unit, 55 ... XY drive unit, A, B, C... Pattern (representative pattern) arranged and formed on mask, A, B1 to B5, C... Same pattern in chip pattern

Claims (1)

The optical axis of the exposure light beam is set so as to pass through the center of the mask, and the optical system is different from the exposure light beam based on the focus leveling information obtained with reference to the intersection point of the optical axis and the wafer. An exposure apparatus that transfers each pattern of the semiconductor device formed on the mask to the wafer while controlling the position and angle of the wafer in the optical axis direction, and includes a plurality of different patterns. In the manufacturing method of the spatial light modulator for transferring the chip onto the wafer,
Preparing a mask in which a plurality of identical patterns for each different pattern in the semiconductor device are arranged and formed on a mask as a single representative pattern,
The representative pattern is arranged in a positional relationship in the arrangement of the plurality of different patterns,
When the formation regions of the same pattern of the semiconductor device to be formed on the wafer are aligned adjacent to each other, the center of the mask is to be formed on the wafer when viewed from the optical axis direction. A method of manufacturing a spatial light modulation element, wherein transfer is performed using the mask so as to be located in a region where the same pattern is formed.

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