JP2008287212A - Mask pattern data generation method, information processing apparatus, photomask fabrication system, and imaging device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent dot pattern symmetry from degrading. <P>SOLUTION: A method for generating mask pattern data of a photomask used to form microlenses 1003 includes: dividing the pattern formation surface of a mask pattern to be formed on the photomask into a plurality of grid cells and acquiring data which represents transmitted light distribution of the mask pattern to be formed on the photomask (S10 to S12); determining whether or not to place a shield on each of the plurality of grid cells by binarizing the plurality of grid cells in order of increasing or decreasing distance from the center of the pattern formation surface using an error diffusion method to acquire the transmitted light distribution (S13); and generating mask pattern data where the plurality of shields are arranged according to results from the determining process (S14). <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to the production of a photomask, and more particularly to the production of a photomask for forming a microlens that exists above a light receiving portion that performs photoelectric conversion of an imaging device such as a CCD or CMOS.

  2. Description of the Related Art Conventionally, in an imaging apparatus, a condensing microlens is provided for each pixel in order to increase the light condensing efficiency to the light receiving unit.

  The microlens is formed by using a photolithographic method to form a photosensitive resin in an island shape so as to correspond to each pixel. The island-shaped resin pattern is heated and softened, and the resin surface is made spherical by its surface tension. It is formed by.

  With the miniaturization of the pixels, the sensitivity of the imaging device is reduced. Therefore, in order to improve the light collection efficiency, it is desired to reduce the interval between the microlenses in order to collect the light incident on the interval between the microlenses. However, when the method of softening the resin pattern by heating is used, it is difficult to narrow the microlens interval. This is because it is necessary to provide a certain gap between the lenses in order to prevent the adjacent lenses from contacting each other by softening the resin by heat treatment.

On the other hand, there is a method of forming a microlens by exposing a photosensitive resin using a photomask capable of controlling the amount of exposure light transmitted by a dot pattern in which a plurality of fine dots are arranged, and performing development processing. It has been proposed (Patent Document 1 and Patent Document 2).
JP 2004-145319 A Japanese Patent Laid-Open No. 2004-700875

  However, in the techniques of Patent Document 1 and Patent Document 2, the arrangement of the dot pattern is not concentric with respect to the pixel center, and the symmetry with respect to the pixel center is low. In such a dot pattern arrangement, the transmitted light amount distribution is not a spherical distribution, and the transmitted light amount distribution with respect to the pixel center is asymmetric. As a result, the shape of the microlens does not become a desired shape, and there is a possibility that a deviation from the design value of optical characteristics (focal length, proportionality of Fno, etc.) may occur.

  The present invention has been made in view of the above problems, and an object of the present invention is to suppress the deterioration of the symmetry of the dot pattern.

  A first aspect of the present invention relates to a method of generating mask pattern data of a photomask for forming a microlens, and a step of dividing a pattern formation surface of a mask pattern to be formed on the photomask into a plurality of lattices A step of acquiring data indicating a transmitted light amount distribution of a mask pattern to be formed on the photomask, and a distance from a center of the pattern forming surface of the plurality of lattices so as to obtain the transmitted light amount distribution. Performing binarization processing by an error dispersion method in order from the nearest grid, determining whether or not to arrange a shielding part in each of the plurality of grids, and based on the results of the determining step Generating mask pattern data in which the shielding part is arranged.

  A second aspect of the present invention relates to a method of generating mask pattern data of a photomask for forming a microlens, and a step of dividing a pattern formation surface of a mask pattern to be formed on the photomask into a plurality of lattices A step of acquiring data indicating a transmitted light amount distribution of a mask pattern to be formed on the photomask, and a distance from a center of the pattern forming surface of the plurality of lattices so as to obtain the transmitted light amount distribution. Performing binarization processing by an error dispersion method in order from a distant lattice, determining whether or not to arrange a shielding portion in each of the plurality of lattices, and based on the results of the determining step Generating mask pattern data in which the shielding part is arranged.

  A third aspect of the present invention relates to an information processing apparatus, and is formed on the photomask for forming a microlens and means for dividing a pattern formation surface of a mask pattern to be formed on a photomask into a plurality of lattices. Means for obtaining data indicating the transmitted light amount distribution of the power mask pattern, and the error dispersion method in order from the lattice having the closest distance from the center of the pattern forming surface among the plurality of lattices so as to obtain the transmitted light amount distribution. Means for performing binarization processing to determine whether or not to arrange a shielding portion on each of the plurality of lattices, and a mask pattern in which the plurality of shielding portions are arranged based on a result of the determining means; Means for generating data.

  A fourth aspect of the present invention relates to an information processing apparatus, and is formed on the photomask for forming a microlens and means for dividing a pattern formation surface of a mask pattern to be formed on a photomask into a plurality of lattices. Means for acquiring data indicating the transmitted light amount distribution of the power mask pattern, and the error dispersion method in order from the lattice having a distance from the center of the pattern formation surface among the plurality of lattices so as to obtain the transmitted light amount distribution. Means for performing binarization processing to determine whether or not to arrange a shielding portion on each of the plurality of lattices, and a mask pattern in which the plurality of shielding portions are arranged based on a result of the determining means; Means for generating data.

  A fifth aspect of the present invention relates to a photomask manufacturing system, comprising: the information processing apparatus described above; and a drawing apparatus that manufactures a photomask based on mask pattern data generated by the information processing apparatus. Features.

  According to a sixth aspect of the present invention, there is provided an imaging device, wherein photoelectric conversion means for converting light into signal charge and a photomask manufactured by the above-described photomask manufacturing system are used to convert light to the photoelectric conversion. And a microlens for condensing on the means.

  According to the present invention, it is possible to suppress the deterioration of the symmetry of the dot pattern.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described in detail with reference to the drawings.

(First embodiment)
FIG. 1 is a block diagram showing a configuration of a photomask manufacturing system according to a preferred first embodiment of the present invention.

  In FIG. 1, a photomask manufacturing system 100 includes an information processing apparatus 101, a drawing apparatus 102, an inspection apparatus 103, and a defect correction apparatus 104. The information processing apparatus 101 generates mask pattern data 105 based on the acquired various data described later. Further, the information processing apparatus 101 converts the generated mask pattern data 105 into drawing data corresponding to the drawing apparatus 102. The drawing apparatus 102 produces a photomask by a reduction transfer method or a direct drawing method based on the drawing data created by the information processing apparatus 101. The inspection apparatus 103 inspects the defect of the photomask and checks whether the dot pattern is formed as designed. There are various inspection methods, and the inspection method is not limited to a specific inspection method. For example, a method of performing inspection by comparing the mask pattern data 105 with an electrical signal of an optical image of a photomask can be used. The defect correcting device 104 corrects the defect detected by the inspection device 103. There are various correction methods, which are not limited to specific limitations. For example, a laser beam method or an ion beam method can be used. Note that the mask pattern data 105 refers to design data for drawing a mask pattern by the drawing apparatus 102. The drawing data refers to data obtained by converting the mask pattern into a data format corresponding to the drawing apparatus 102.

  FIG. 2 is a flowchart showing a photomask manufacturing method using the photomask manufacturing system 100.

  In step S10, various data are prepared. The various data includes a sensitivity curve of photosensitive resin for forming a minute lens (hereinafter referred to as “microlens”) and desired lens shape data. The sensitivity curve of the photosensitive resin for forming a microlens is a curve showing a change in the remaining film thickness of the photosensitive resin with respect to the exposure amount. Usually, the sensitivity curve of the positive photosensitive resin is as shown in FIG. In FIG. 3, both the exposure amount and the remaining film thickness are normalized.

In step S11, the information processing apparatus 101 determines a function z = F (x, y) representing the transmitted light amount distribution of the mask pattern to be formed on the photomask based on the various data prepared in step S10. If the sensitivity curve prepared in step S10 is used, the transmitted light amount (exposure amount to the irradiated object) for forming a desired lens shape is changed to an XY plane (pattern forming surface) on which a photomask pattern is formed. It can be expressed as a function of the upper position. Here, an example in which a certain lens shape is produced using the sensitivity curve of FIG. If the position on the XY plane is the distance from the pixel center, the relationship between the distance from the pixel center and the amount of transmitted light (also referred to as transmittance) is as shown in FIG. 4, and this relationship is as shown in FIG. It can be approximated by a quadratic function. The information processing apparatus 101, to coordinates x, y of each grid when dividing the the x-y plane to form a pattern of the photomask to the plurality of grid with pitch W _1, transmitted light quantity z value on z-coordinate Is calculated. Then, a quadratic function representing the relationship between the amount of transmitted light and the distance from the pixel center determined above is z = F (x, y).

FIG. 5A shows a transmitted light amount distribution of one pixel for obtaining a desired lens shape by calculating z values for the coordinate values x and y using the quadratic function calculated in step S11. FIG. 5B is a list showing a part of the transmitted light amount distribution shown in FIG. 5A and showing the transmitted light amount z value with respect to the coordinate values x and y. The pitch W ₁ when calculating the transmitted light amount z value is smaller than the resolution limit length (corresponding to the resolution) of the exposure apparatus used for forming the microlens. For example, when the wavelength of exposure light is 365 nm and a quadruple reticle (photomask) is used, if the size of one side of the dot on the photomask is 0.96 μm (= 960 nm) or more, The dot pattern is resolved in the photosensitive resin. As a result, it has been confirmed by experiments that a smooth desired lens shape cannot be formed. The lower limit is determined based on the resolution limit length of the drawing apparatus 102 when forming the photomask. On the other hand, when the size of one side of the dot on the photomask is 0.24 μm (= 240 nm) to 0.72 μm (= 720 nm) μm, it is confirmed that no resolution is obtained at the wavelength of exposure light of 365 nm. . Therefore, it is preferable that the pitch W ₁ of the grating on the drawing apparatus 102 is in the range of 60 nm to 180 nm (240 nm to 720 nm on the photomask). Here, the “dot” means a shielding part having the same shape as the above-described grid, and one dot is arranged for each barycentric point of each grid. Moreover, it is preferable that a dot (shielding part) is a shape which does not have an acute angle, and it is more preferable that it is a square lattice.

  In step S12, the distance r from the pixel center (x0, y0) of the coordinates (x, y) of the grid obtained by dividing the XY plane at a predetermined pitch is calculated based on the equation (1).

r = ((x−x ₀ ) ² + (y−y ₀ ) ² ) ^1/2 (Formula 1).

In step S13, the information processing apparatus 101 binarizes the calculated transmitted light amount z value on the z coordinate by an error dispersion method (error diffusion method) in the order described later in order to control the transmitted light amount of exposure light. Perform the process. Then, the information processing apparatus 101 determines whether or not the chrome light shielding (shielding portion) is disposed in each divided grid, and generates a dot pattern having a length of W _{1 on} one side.

  In step S14, the information processing apparatus 101 generates mask pattern data in which the dot pattern generated in step S13 is arranged on the XY plane in a drawing apparatus such as CAD (corresponding to FIG. 9B). . Further, the information processing apparatus 101 converts the generated mask pattern data into drawing data corresponding to the drawing apparatus 102.

  In step S15, the drawing apparatus 102 produces a photomask using the drawing data generated in step S14.

  In step S16, the inspection apparatus 103 inspects whether or not the pattern is formed as designed.

  In step S <b> 17, the defect correction device 104 corrects the defect detected by the inspection device 103.

  Next, the procedure of binarization processing by the error variance method in step S13 of FIG. 2 will be described using FIG.

  In FIG. 6, it is assumed that the horizontal direction is the X coordinate and the vertical direction is the Y coordinate, and the transmitted light quantity z with respect to the coordinates (x, y) is arranged in a grid divided at a predetermined pitch. In FIG. 6, an example in which the grid is divided into 5 × 5 grids will be described, but the present invention is not limited to this. Here, binarization means that 1 is assigned when the value of the transmitted light amount is larger than the threshold value, and 0 is assigned when the value of the transmitted light amount is smaller than the threshold value. Further, in this embodiment, binarization is performed with an intermediate value of the transmitted light amount of 0.5 as a threshold value, but the present invention is not limited to this. A grid assigned 1 is an opening (no chrome light shielding film), and a grid assigned 0 is a light shielding part (with a chrome light shielding film, that is, a dot). The binarization processing starts from a lattice at the pixel center, and performs processing counterclockwise in order from a lattice having a smaller value of the distance r from the pixel center.

  First, as shown in FIG. 6A, in the lattice at the pixel center, binarization is performed with an intermediate value of 0.5 as a threshold value, and the transmitted light amount becomes 0.1 to 0.

  Next, as shown in FIG. 6B, the error (0.1-0 = 0.1) caused by the binarization is weighted and added (or subtracted) to eight grids adjacent to the binarized grid. ) FIG. 7 is a diagram illustrating an example of weighting. In FIG. 7, a weight of 1 is assigned to the upper, lower, left, and right grids, and a weight of 0.5 is assigned to the upper left, upper right, lower left, and lower right grids. Therefore, the amount of light transmitted through the upper grid ((1) in FIG. 6B) is 0.2 + 0.1 / (1 + 1 + 1 + 1 + 0.5 + 0.5 + 0.5 + 0.5) = 0.22. Similarly, weighting is performed on the transmitted light amount of the adjacent grating based on the weighting of FIG.

  Next, as shown in FIG. 6 (c), it moves to an adjacent lattice and performs the above binarization. In FIG. 6C, binarization is performed with the intermediate value 0.5 as a threshold value in the lattice after movement, and the transmitted light amount is changed from 0.22 to 0.

  Next, as shown in FIG. 6 (d), the error (0.22-0 = 0.22) caused by the binarization is reduced to eight adjacent to the binarized grid based on the weighting of FIG. Weighted addition (or subtraction) to the grid. In FIG. 6D, the amount of light transmitted through the upper grating is 0.21 + 0.22 / (1 + 1 + 1 + 0.5 + 0.5 + 0.5 + 0.5) = 0.22. Similarly, weighting is performed on the transmitted light amount of the adjacent grating based on the weighting of FIG. It should be noted that the error is not weighted (or subtracted) from the lattice after the binarization processing is completed.

  In FIG. 6E, the same processing is performed in the order indicated by the arrows. That is, after starting from the pixel center grid, each grid is processed in the order of right, top, left, bottom, top right, top left, bottom left, bottom right, and the distance r from the pixel center of the grids outside the grid. Process in the order of the closest grids. As described above, since the binarization process is performed in a spiral manner for each pixel equidistant from the center pixel, it is possible to obtain a concentric and highly symmetric dot pattern arrangement with respect to the pixel center.

  FIG. 9 is a diagram showing a dot pattern obtained by the binarization process shown in FIG. FIG. 9A shows the calculated ratio (aperture ratio) of the lattices opened in the range surrounded by the frame A. FIG. FIG. 9B shows a dot pattern when 0 is a light shielding portion (dot) and 1 is an opening. As shown in FIG. 9A, the aperture ratio is 26% in the upper right area, the aperture ratio is 27% in the upper left area, the aperture ratio is 25% in the lower left area, and the aperture ratio is 26% in the lower right area. Met.

  FIG. 10 shows, as a comparative example, dot patterns obtained by performing binarization processing by the error dispersion method from the pixel center to the four corner directions described in Patent Document 2 (see FIGS. 10A and 10C). FIG. FIG. 10A shows the calculated ratio (aperture ratio) of the lattices opened in the range surrounded by the frame B. FIG. FIG. 10B shows a dot pattern when 0 is a light shielding portion (dot) and 1 is an opening. As shown in FIG. 10A, the aperture ratio is 31% in the upper right region, 33% in the upper left region, 31% in the lower left region, and 28% in the lower right region. Met.

  As described above, the dot pattern shown in FIG. 9 has an aperture ratio shift of only 2% and has a substantially symmetrical arrangement. On the other hand, the dot pattern shown in FIG. 10 has a deviation of 5% in the aperture ratio, and its arrangement symmetry is also lower than that of the dot pattern of FIG.

  As described above, the binarization processing according to the present embodiment can suppress the deterioration of the symmetry of the dot pattern. Thereby, a good quality microlens with less distortion of the lens shape can be produced.

  In the description of the present embodiment, the case where data indicating the transmitted light amount distribution of the mask pattern to be formed on the photomask is used. However, for example, the present invention can also be applied to the case where data indicating the transmitted light amount distribution of a mask pattern to be formed on a photomask is acquired in advance and used.

  In the description of the present embodiment, the case where the transmitted light amount distribution of the mask pattern to be formed on the photomask is used. However, the present invention includes the case where the masking amount distribution of the mask pattern to be formed on the photomask is used. It is.

(Second Embodiment)
In the first embodiment, the binarization process by the error dispersion method is performed in the spiral direction as shown in FIG. 8A in step S13 of FIG. 2, but the binarization process by the error dispersion method is performed. May be performed in other directions. As such binarization processing, as shown in FIG. 8B, the binarization processing may be performed in the clockwise direction in the order of the distance r from the center pixel. Further, as shown in FIG. 8C or FIG. 8D, the binarization process may be performed in the order of the distance r from the center pixel. However, in order to suppress the deterioration of symmetry, the processing must be performed in either order of the grids with the distance r from the pixel center closer or processing in the order of the grids with the distance r away from the pixel center. .

(Third embodiment)
In the first embodiment and the second embodiment was conducted binarization processing using a grid obtained by dividing one pixel in step S13 in FIG. 2 at a predetermined pitch W _1. Although this method can suppress the deterioration of symmetry of the generated dot pattern, it may not be able to reproduce the transmitted light amount distribution for obtaining a desired lens shape. This is because the grid existing inside the pixel can add (or subtract) errors in multiple directions (8 directions) as shown in FIG. 12A, whereas the outermost grid is shown in FIG. This is because the error can be weighted and added (or subtracted) only in a small number of directions (two directions). For this reason, the number of grids capable of weighted addition (or subtraction) of errors decreases, and weighted addition (or subtraction) equivalent to other grids may not be possible. That is, there is a possibility that appropriate binarization is not performed when binarizing the outermost periphery grid.

  In order to solve the above problem, an additional lattice (dummy lattice) is added outside the outermost periphery lattice as shown in FIG. 13A so as to be adjacent to the lattice existing on the outermost periphery of the pixel. Then, the binarization process may be performed after increasing the number of grids that can be weighted (or subtracted) from the error of the outermost grid. That is, it is possible to match the number of grids that can be weighted (or subtracted) with errors in the outermost grid and the number of grids that can be weighted (or subtracted) with errors in the grid existing inside the pixel. The dummy grid is a grid used only when the error is weighted and added (or subtracted) when performing the binarization process, and the binarization process result of the dummy grid is not used in step S14 of FIG. In this way, by adding a dummy lattice and performing binarization processing, it is possible to perform appropriate chrome shading arrangement, and as a result, a dot pattern arrangement that can reproduce the transmitted light amount distribution to obtain a desired lens shape Can be produced. FIG. 12C is a diagram showing a result of error dispersion processing of the outermost periphery lattice when no dummy lattice is used. The value after the weighted addition (or subtraction) of the grid adjacent to the processing grid is different from that in FIG. 13B when the dummy grid is used. This difference in value corresponds to a deviation from the transmitted light amount distribution for obtaining a desired lens shape.

  The binarization processing method to which the dummy lattice is added is not limited to the binarization processing direction shown in the first embodiment and the second embodiment, and the binarization processing of the lattice existing on the outermost periphery of the pixel It is a method that can sometimes give appropriate results. By using in combination with the first embodiment and the second embodiment, it is possible to obtain a dot pattern arrangement for obtaining a desired lens shape in which deterioration of symmetry is suppressed. In particular, when the lens (curvature) extends to the outermost periphery of the pixel, it is possible to obtain a dot pattern arrangement for obtaining a desired lens shape.

(Application examples)
FIG. 11 is a diagram illustrating a configuration of an image sensor including a microlens manufactured using a photomask manufacturing system 100 according to a preferred embodiment of the present invention. In the imaging device, a plurality of pixels are two-dimensionally arranged, and a microlens is disposed in each pixel. A plurality of mask patterns obtained as shown in FIG. 9 (or FIG. 13) are preferably arranged on the photomask (reticle). When the dummy grid shown in FIG. 13 is used, after the mask pattern for the first pixel is formed, a plurality of mask patterns excluding the dummy grid are arranged to form a mask pattern corresponding to the plurality of pixels. Can do. Using such a photomask (reticle), a plurality of microlenses (microlens array) are formed on the substrate 1001 by a known lithography technique. The imaging device includes photoelectric conversion means 1002 formed on a substrate 1001, microlenses 1003 that are two-dimensionally arrayed using a photomask manufacturing system 100, and a color filter 1004. The photoelectric conversion means 1002 is a photoelectric conversion means such as a photodiode that converts light into signal charges and accumulates them. The micro lens 1003 condenses light on the photoelectric conversion means 1002. The color filter 1004 is disposed between the microlens 1003 and the photoelectric conversion unit 1002.

  Conventional microlenses are formed by heating and softening a resin material. Therefore, it is necessary to provide a gap between the microlenses so that adjacent microlenses are not connected.

  In contrast, in a preferred embodiment of the present invention, the distortion of the lens shape is reduced by manufacturing the microlens 1003 using a photomask manufactured using the photomask manufacturing system 100. Therefore, the process of heating the resin material is unnecessary, and the gap between the microlenses can be greatly reduced.

1 is a block diagram showing a configuration of a photomask manufacturing system according to a preferred first embodiment of the present invention. It is a flowchart which shows the photomask manufacturing method using the photomask manufacturing system. It is a figure which shows the sensitivity curve of positive type photosensitive resin. It is a figure which shows the relationship between the distance from a pixel center, and the transmitted light amount (exposure amount) using the sensitivity curve of FIG. (A) is a figure which shows the transmitted light amount distribution in 1 pixel for obtaining a desired lens shape. (B) is a figure which shows the list showing the transmitted light quantity z value with respect to the coordinate values x and y in a part of transmitted light quantity distribution shown to (a). It is a figure for demonstrating the binarization process by the error dispersion method which concerns on the suitable 1st Embodiment of this invention. It is a figure which shows an example of weighting. It is a figure for demonstrating the binarization process by the error dispersion method which concerns on the suitable 2nd Embodiment of this invention. It is a figure which shows the dot pattern obtained by the binarization process by the error dispersion method which concerns on suitable 1st Embodiment of this invention. It is a figure which shows the dot pattern obtained by the binarization process by the conventional error dispersion method. It is a figure which shows the structure of an image pick-up element provided with the micro lens produced using the photomask production system which concerns on suitable embodiment of this invention. (A) is the figure which showed the direction which carries out weighting addition (or subtraction) of an error at the time of the binarization process of the lattice inside a pixel which concerns on 1st Embodiment. FIG. 6B is a diagram illustrating a direction in which an error is weighted (or subtracted) during binarization processing of the outermost pixel grid according to the first embodiment. (C) is the figure which showed the result after the binarization process of (b). (A) is the figure which showed the direction which carries out weight addition (or subtraction) of an error at the time of the binarization process of the outermost pixel grid according to the third embodiment. (B) is the figure which showed the result after the binarization process of (a).

Explanation of symbols

1001 Substrate 1002 Photoelectric conversion means 1003 Micro lens 1004 Color filter

Claims (11)

A method of generating mask pattern data of a photomask for forming a microlens,
Dividing a pattern forming surface of a mask pattern to be formed on the photomask into a plurality of lattices;
Obtaining data indicating a transmitted light amount distribution of a mask pattern to be formed on the photomask;
In order to obtain the transmitted light amount distribution, binarization processing by error dispersion method is sequentially performed from the plurality of grids with a distance from the center of the pattern formation surface in order to shield each of the plurality of grids. Determining whether to place a part;
Generating mask pattern data indicating the arrangement of the plurality of shielding portions based on the result of the determining step;
A method of generating mask pattern data, comprising: A method of generating mask pattern data of a photomask for forming a microlens,
Dividing a pattern forming surface of a mask pattern to be formed on the photomask into a plurality of lattices;
Obtaining data indicating a transmitted light amount distribution of a mask pattern to be formed on the photomask;
In order to obtain the transmitted light amount distribution, binarization processing is performed by an error dispersion method in order from a lattice far from the center of the pattern formation surface among the plurality of lattices, thereby shielding each of the plurality of lattices. Determining whether to place a part;
Generating mask pattern data in which the plurality of shielding portions are arranged based on a result of the determining step;
A method of generating mask pattern data, comprising:   3. The method of generating mask pattern data according to claim 1, wherein, in the determining step, the binarization processing is performed clockwise for each of the plurality of lattices.   3. The method of generating mask pattern data according to claim 1, wherein, in the determining step, the binarization processing is performed counterclockwise for each of the plurality of grids.   5. The generation of mask pattern data according to claim 1, wherein a length of each side of each of the plurality of gratings is equal to or less than a resolution limit length of an exposure apparatus for the photomask. Method.   The mask pattern data generation method according to claim 1, wherein the plurality of lattices are square lattices.   The determining step includes adding an additional grid outside a grid existing on the outermost periphery of the plurality of grids, and performing the binarization process together with the additional grid. The method for generating mask pattern data according to any one of claims 1 to 6. Means for dividing a pattern forming surface of a mask pattern to be formed on a photomask into a plurality of lattices;
Means for obtaining data indicating a transmitted light amount distribution of a mask pattern to be formed on the photomask for forming a microlens;
In order to obtain the transmitted light amount distribution, binarization processing by error dispersion method is sequentially performed from the plurality of grids with a distance from the center of the pattern formation surface in order to shield each of the plurality of grids. Means for deciding whether to place a part;
Means for generating mask pattern data in which the plurality of shielding portions are arranged based on the result of the determining means;
An information processing apparatus comprising: Means for dividing a pattern forming surface of a mask pattern to be formed on a photomask into a plurality of lattices;
Means for obtaining data indicating a transmitted light amount distribution of a mask pattern to be formed on the photomask for forming a microlens;
In order to obtain the transmitted light amount distribution, binarization processing is performed by an error dispersion method in order from a lattice far from the center of the pattern formation surface among the plurality of lattices, thereby shielding each of the plurality of lattices. Means for deciding whether to place a part;
Means for generating mask pattern data in which the plurality of shielding portions are arranged based on the result of the determining means;
An information processing apparatus comprising: An information processing apparatus according to claim 8 or claim 9,
A drawing device for producing a photomask based on the mask pattern data generated by the information processing device;
A photomask manufacturing system comprising: Photoelectric conversion means for converting light into signal charge;
A microlens for condensing light on the photoelectric conversion means, formed using a photomask produced by the photomask production system according to claim 10;
An image pickup device comprising:

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