Exposure device and exposure method

Abstract

The invention provides an exposure apparatus and an exposure method. Provided is a maskless exposure device capable of performing data processing for forming a pattern of higher resolution. The exposure device (10) is provided with a grid conversion unit (60). A grid conversion unit (60) generates divided vector data from the vector data for each unit region, and generates divided grid data comprising a cell size smaller than a projection region of the micromirror.

Description

Technical Field

[0001] The present invention relates to a maskless exposure device for patterning using an array of light modulation elements such as a DMD, and more particularly to a series of data processing from input of drawing data to exposure operation. Background Art

[0002] In the manufacturing process of circuit boards, a substrate coated with or pasted with photosensitive materials such as photoresists is subjected to a drawing process (exposure operation). In the drawing process, pattern data (vector data) sent from a CAD system is converted into raster data, and the DMD is driven and controlled based on the raster data.

[0003] In the drawing process, multiple exposures with overlapping exposures are performed, and corresponding data conversion processing, data transmission, data update processing, etc. are performed. Since a large amount of data conversion and data update need to be frequently performed, data transmission and data conversion processing take time, which has an overall impact on throughput.

[0004] In order to reduce data processing, for example, only a portion of vector data is extracted, the extracted vector data is converted into raster data, and then the DMD is driven and controlled (see Patent Document 1). In addition, a plurality of memories (first memory to Nth memory) are prepared for raster data, and the raster data stored in each memory is sequentially shifted to an adjacent memory while the DMD is driven and controlled (see Patent Document 2).

[0005] Patent Document 1: Japanese Patent No. 4203649

[0006] Patent Document 2: Japanese Patent No. 5258226

[0007] In recent years, maskless exposure devices have been required to perform pattern formation with higher resolution. However, due to the characteristics and performance of light modulation element arrays such as DMD, the resolution is limited. Summary of the invention

[0008] Therefore, it is required to provide an exposure apparatus capable of performing data processing for forming a pattern with higher resolution.

[0009] In the present invention, in the raster conversion processing of vector data, the technical trend is toward raster conversion processing for generating raster data based on bit data of a cell unit different from the cell unit (cell size) of each light modulation element.

[0010] An exposure device as one embodiment of the present invention has a raster data conversion unit that converts vector data into raster data (here, referred to as subdivided raster data) composed of unit units having a size smaller than a projection area of ​​light modulators constituting a light modulator array.

[0011] The subdivided grid data may be constituted as bit data in which pixel data is arranged in a matrix shape at a data interval smaller than a data interval of bit data corresponding to a cell size of the light modulator. For example, the grid data conversion unit may generate the subdivided grid data in such a way that the size of a cell unit of the subdivided grid data is less than 1 / 10 of the projection area of ​​the light modulator.

[0012] Furthermore, the exposure device includes: a grid data extraction unit that extracts pixel data corresponding to each light modulator from the subdivided grid data according to the relative position of the exposure area of ​​the light modulator array to generate drawing grid data; and an exposure unit that drives and controls each light modulator according to the generated drawing grid data. For example, the grid data extraction unit can extract pixel data corresponding to the center position of the projection area of ​​the light modulator during the exposure operation.

[0013] The exposure device may further include a grid memory capable of writing subdivided grid data. For example, the memory area of ​​the grid memory may be configured to correspond to a band area larger than the exposure area of ​​the light modulation element array.

[0014] The exposure device may include a segmentation vector data generating unit, which generates segmentation vector data by segmenting the vector data according to the unit area set along the scanning band area of ​​the light modulator array. The raster data conversion unit may convert the segmentation vector data into subdivided raster data respectively. For example, the raster data conversion unit may set the unit area of ​​the segmentation vector data according to the size of the unit unit of the subdivided raster data.

[0015] The processing speed of the raster conversion process is affected by the size of the unit unit of the subdivided raster data. The exposure device may include a segmentation vector data generating unit that generates segmentation vector data by segmenting the vector data according to the unit area set along the scanning band area of ​​the light modulation element array. For example, the raster data conversion unit may convert the segmentation vector data into the subdivided raster data.

[0016] For example, the exposure device may have a raster memory capable of writing raster data generated according to each segmentation vector data, and the raster data conversion unit may convert the raster data into raster data according to the free state of the raster memory (for example, the free capacity corresponding to the memory area corresponding to the segmentation vector data).

[0017] Furthermore, the memory area of ​​the raster memory can be configured to correspond to a band area larger than the exposure area of ​​the light modulator array, and the data processing of the raster data conversion unit can facilitate the sequential and continuous transmission of raster data to the raster memory.

[0018] In an exposure method which is another embodiment of the present invention, vector data is converted into subdivided raster data, which is composed of unit units whose size is smaller than the projection area of ​​the light modulator element. According to the relative position of the exposure area of ​​the light modulator element array, pixel data corresponding to each light modulator element is extracted from the subdivided raster data to generate drawing raster data, and each light modulator element is driven and controlled according to the generated drawing raster data.

[0019] According to the present invention, for a maskless exposure apparatus, it is required to provide an exposure apparatus capable of performing data processing for forming a pattern with a higher resolution. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a block diagram of the exposure apparatus of this embodiment.

[0021] Figure 2 2 is a diagram showing a part of the raster conversion process performed in the raster conversion section.

[0022] Figure 3 2 is a diagram showing extraction processing of segmented raster data performed in the extraction unit.

[0023] Figure 4 : is a flowchart showing the processing flow of the raster conversion unit, the extraction unit, and the exposure unit.

[0024] Description of symbols

[0025] 10: exposure device; 30: DMD; 60: grid conversion unit; 70: extraction unit; 80: exposure unit. DETAILED DESCRIPTION

[0026] Hereinafter, the exposure apparatus according to the present embodiment will be described using the drawings.

[0027] Figure 1 1 is a block diagram of an exposure device of the present embodiment. The exposure device 10 is configured as a maskless exposure device capable of forming a pattern on a substrate W such as a printed circuit board. The substrate W is mounted on a workbench 50, and the workbench 50 can be moved in the main scanning direction (X direction) and the sub-scanning direction (Y direction) by means of an XY workbench mechanism (not shown).

[0028] The exposure device 10 includes a plurality of exposure heads 20, each of which includes an illumination optical system (not shown), a DMD (Digital Micro-mirror Device) 30, a projection optical system 40, etc. The plurality of exposure heads 20 are arranged at predetermined intervals along the sub-scanning direction (Y direction) (in the Figure 1 Only one exposure head 20 is shown in the figure. Light output from a light source such as laser (not shown) is projected onto the substrate W via the illumination optical system, DMD 30, and projection optical system 40.

[0029] In the DMD 30 obtained by arranging rectangular micromirrors in a two-dimensional matrix, each micromirror is controlled to be turned on (ON) / off (OFF). The light reflected by the micromirrors becomes pattern light and is guided to the projection optical system 40, and is imaged on the surface of the photosensitive material coated or pasted on the substrate W. The imaging magnification is set according to the optical performance of the projection optical system 40, and is set to 1 here.

[0030] The exposure device 10 is connected to a CAD system or the like, and the controller 90 controls the operation of the exposure device 10. A series of data processing related to exposure is performed in accordance with the input of drawing data sent from the CAD system or the like.

[0031] exist Figure 1 , a part of the structure of the exposure device 10 is shown in a functional summary. The exposure device 10 includes a raster conversion unit 60, an extraction unit 70, and an exposure unit 80.

[0032] The raster conversion unit 60 includes a vector data segmentation unit 62 and a raster data conversion unit 64. The raster conversion unit 60 performs a raster conversion process to convert the drawing data, which is vector data, into raster data. The raster data generated by the raster conversion process is stored in the raster memory 92. In addition, the drawing data, which is vector data, may be converted into raster data through alignment correction processing, coordinate conversion processing, etc.

[0033] The extraction unit 70 includes a grid data extraction unit 72 and an image data memory 74. In the extraction unit 70, grid data (raster data) composed of pixels (pixel, bit) corresponding to the positions of each micromirror of the DMD 30 are extracted from the grid data stored in the grid memory 92. Thus, the on / off state of each micromirror of the DMD 30 is set. Hereinafter, the grid data constituting the pattern image formed by the micromirrors of the DMD 30 is referred to as "screen data" as needed. The screen data is temporarily stored in the image data memory 74.

[0034] The exposure unit 80 has the above-mentioned exposure head 20, a stage measuring unit 82, and a data transmission unit 84. The data transmission unit 84 transmits the picture data corresponding to the relative position of the exposure area from the image data memory 74 to the DMD 30 based on the stage position information sent from the stage measuring unit 82. Each micromirror of the DMD 30 is turned on / off controlled (driven controlled) based on the sent picture data.

[0035] In the exposure operation, as the stage 50 moves in the main scanning direction (X direction), the exposure area as the projection area of ​​the DMD 30 moves relative to the substrate W in the main scanning direction (X direction). Here, the exposure head 20 is configured so that the exposure area is tilted at a slight tilt angle α relative to the main scanning direction (X direction).

[0036] While the stage 50 is moving at a constant speed, a multiple exposure operation (overlap exposure) is performed according to a preset exposure pitch. The entire substrate W is subjected to a drawing process by performing the multiple exposure operation on each strip-shaped scanning area (hereinafter referred to as a scanning strip area).

[0037] In a series of data processing related to exposure, the raster data conversion processing of the raster conversion unit 60 and the raster data extraction processing of the extraction unit 70 are independently performed in the exposure device 10. And the raster data conversion processing of the raster conversion unit 60 is performed according to the processing status of the raster data extraction processing of the extraction unit 70 and the multi-exposure operation of the exposure unit 80.

[0038] Furthermore, the raster data generated by the raster data conversion processing of the raster conversion unit 60 is not raster data in which the data interval is set to match the size of the projection area (micro-dot area) of each micromirror of the DMD 30, but is raster data in which the data interval is set in a unit size unit (pixel size unit) smaller than the projection area size (hereinafter referred to as subdivided raster data).

[0039] Below, use Figure 2 , Figure 3 , the independence (non-linkage) of such data processing and the generation process of segmented raster data are explained.

[0040] Figure 2 2 is a diagram showing a part of the raster conversion process performed in the raster conversion section 60. Here, the scanning band area of ​​the DMD 30 is shown by reference symbol "BD".

[0041] A unit area is pre-set for the scanning band area BD. The unit area indicates a data area that is a block when the drawing data (vector data) is locally extracted and the data is divided. The size of the unit area is set according to the processing speed of the raster conversion process, etc. Figure 2In FIG. 1 , unit areas set in the scanning band area BD are represented by reference numerals VP0 to VPn.

[0042] The drawing data as vector data is divided into unit areas. In the vector data obtained by the division (hereinafter referred to as the segmented vector data), the characteristic point Bd of the pattern appears on the boundary line (hereinafter also referred to as the segmentation line) L of the predetermined unit area. Therefore, the position coordinates (X, Y coordinates) of the characteristic point Bd located on the boundary line L are calculated for the segmented vector data of each unit area.

[0043] The raster data conversion unit 64 converts the segmented vector data into raster data. At this time, as described above, the subdivided raster data as the bitmap data composed of the unit size unit smaller than the size of the projection area of ​​the micromirror is generated. Here, the size of each bit data (pixel data) constituting the subdivided raster data is set to be less than a few tenths of the size of the projection area of ​​the micromirror.

[0044] The subdivided raster data is generated for each segmented vector data and stored in the raster memory 92. Here, the raster memory 92 is configured as a buffer memory having a ring buffer function.

[0045] The generated subdivided raster data is written as needed in the raster memory 92. The controller 90 controls writing of the subdivided raster data into the raster memory 92, and writes the subdivided raster data into the raster memory 92 according to the free space of the raster memory 92.

[0046] Figure 3 2 is a diagram showing extraction processing of segmented raster data performed in the extraction unit 70 .

[0047] The subdivided grid data is constituted in the grid memory 92 as image data obtained by integrating the patterns. Figure 3 As shown, the memory area of ​​the raster memory 92 corresponds to a band area larger than the exposure area EA of the DMD 30. The storage position of the subdivided raster data is changed according to the exposure pitch PP. The controller 90 controls the reading of the subdivided raster data in the raster memory 92.

[0048] In the grid data extraction unit 72, pixel data (bit data) corresponding to the position of each micromirror is extracted from the subdivided grid data stored in the grid memory 92 according to the relative position of the exposure area of ​​the DMD 30. Specifically, the exposure center position CC of each micromirror during the exposure operation is calculated, and the pixel data (bit data) corresponding to the position is extracted from the subdivided grid data.

[0049] Then, based on the bitmap data obtained by configuring the extracted bit data according to the micromirror arrangement, the drawing grid data is generated. As described above, the subdivided grid data is grid data generated with a resolution smaller than the screen resolution of the DMD 30, but the resolution of the drawing grid data is consistent with the screen resolution of the DMD 30.

[0050] exist Figure 3 In FIG. 1 , the exposure center position is indicated by CC, and the extracted subdivided grid data is indicated by RM. In addition, the exposure center position CC and the extracted subdivided grid data RM are illustrated as a dot pattern whose cell size unit is larger than the subdivided grid data BR before extraction, that is, the data interval is larger.

[0051] The extracted subdivided grid data RM becomes data for setting the on / off state of the corresponding micromirror. Therefore, the extraction of the subdivided grid data RM corresponding to the exposure operation generates image data, that is, screen data, of the pattern represented by the micromirrors constituting the DMD 30. Figure 3 , the screen data sequentially generated according to the exposure pitch PP is shown.

[0052] Here, the generation of segmented vector data and subdivided raster data in the raster conversion unit 60 is continuously and repeatedly performed as a series of data processing. On the other hand, the extraction of subdivided raster data by the extraction unit 70 is not performed in conjunction with the data processing of the raster conversion unit 60, but is performed independently.

[0053] That is, by temporarily storing the generated subdivided raster data in the raster memory 92 as a buffer memory, it is possible to perform extraction processing of the subdivided raster data and generation of screen data independently of the raster conversion processing.

[0054] The exposure unit 80 performs a multiple exposure operation according to the generation of the picture data, that is, according to the exposure pitch PP. Therefore, the data processing of the extraction unit 70 and the exposure unit 80 is a data processing that is continuously and repeatedly performed according to the exposure pitch PP. These data processings are performed through the raster memory 92 as a buffer memory without being linked to the raster conversion processing of the raster conversion unit 60.

[0055] In addition, whether or not the raster memory 92 can be written depends on the free space of the raster memory 92. As described above, the data processing of the extraction unit 70 and the exposure unit 80 is performed according to the exposure pitch PP, and the extraction processing of the subdivided raster data produces a state in which the subdivided raster data can be written in the raster memory 92. The generation processing of the segmented vector data and the subdivided raster data is repeatedly performed according to the free space of the raster memory 92.

[0056] As described above, in the exposure device 10 of the present embodiment, the data processing of the raster conversion unit 60 and the extraction unit 70 are independently performed via the raster memory 92. With respect to a series of processes related to exposure, the processing contents are divided from a functional point of view and repeatedly executed in the divided processing groups, so that data processing can be efficiently performed while maintaining throughput.

[0057] Furthermore, in the present embodiment, the raster conversion unit 60 generates segmented vector data for each unit area BD from the vector data, and generates segmented raster data BR composed of a unit size smaller than the projection area of ​​the micromirror.

[0058] The subdivided grid data corresponding to the exposure center position of each micromirror is selected and extracted from the subdivided grid data whose unit size is much smaller than the projection area size of the micromirror of the DMD 30. Therefore, the on / off state of each micromirror can be appropriately set for the relative position of the exposure area EA (the exposure center position of the micromirror), and the pattern can be formed with high precision.

[0059] Figure 4 1 is a flowchart showing the flow of processing by the raster conversion section 60 , the extraction section 70 , and the exposure section 80 .

[0060] In the raster conversion unit 60, the raster conversion process (S101 to S106) is repeatedly executed according to the free space of the raster memory 92. Here, the unit area is managed in the form of dividing line numbers.

[0061] In the extraction unit 70, pixel data (bit data) corresponding to the position of each micromirror is selected from the subdivided grid data stored in the grid memory 92, and the picture data, that is, the drawing grid data as bitmap data corresponding to the resolution of the DMD 30 is stored in the image data memory 74 (S201-S208). Here, the number of the picture data is managed in the form of generating a picture number.

[0062] In the exposure unit 80, a multiple exposure operation is performed along with reading of the screen data (S301 to S306). The timing of the exposure operation according to the exposure pitch is managed in the form of exposure numbers.

[0063] Regarding the exposure device 10, if the focus is on the structure in which the raster conversion unit 60 and the extraction unit 70 perform data processing in a non-linked manner, a structure that does not generate subdivided raster data may be adopted. On the other hand, if the focus is on the structure in which subdivided raster data is generated, a structure in which the raster conversion unit 60 and the extraction unit 70 perform data processing in a non-linked manner may not be adopted.

[0064] The exposure device 10 can be configured to branch the pattern light of the light modulator array in the sub-scanning direction by a split optical system (branch optical system) and scan along different scanning bands. The above-mentioned data processing can also be applied to such an exposure device 10 .

Claims

1. An exposure device, characterized in that: The exposure device has: a raster data conversion unit that converts the vector data into subdivided raster data composed of unit units having a size smaller than a projection area of ​​a light modulator constituting the light modulator array; a grid data extraction unit, which extracts pixel data corresponding to each light modulator from the subdivided grid data according to the relative position of the exposure area of ​​the light modulator array, and generates drawing grid data; as well as An exposure unit controls driving of each light modulation element based on the generated drawing grid data.

2. The exposure device according to claim 1, characterized in that The exposure device also has a grid memory, which can write the subdivided grid data. The memory area of ​​the grid memory corresponds to a band area larger than the exposure area of ​​the light modulation element array.

3. The exposure device according to claim 1, characterized in that The size of a unit unit of the subdivided grid data is less than 1 / 10 of the projection area of ​​the light modulation element.

4. The exposure device according to claim 1, characterized in that The exposure device further includes a segmentation vector data generating unit that generates segmentation vector data by segmenting the vector data according to unit areas set along the scanning band area of ​​the light modulation element array. The raster data conversion unit converts the segmented vector data into the segmented raster data.

5. An exposure method, characterized in that: The vector data is converted into subdivided raster data, which consists of unit units with a size smaller than the projection area of ​​the light modulation element. According to the relative position of the exposure area of ​​the light modulator array, the pixel data corresponding to each light modulator is extracted from the subdivided grid data to generate the drawing grid data. The driving of each light modulation element is controlled based on the generated drawing grid data.

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