Exposure device and exposure method

Abstract

To provide an exposure device capable of performing data processing for forming a pattern having a higher resolution to a maskless exposure device.SOLUTION: An exposure device 10 includes a raster converter 60. The raster converter 60 fits vector data to a unit area to create division vector data and creates subdivision raster data constituted of a cell size smaller than the projection area of a micro mirror.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a maskless exposure apparatus that performs patterning using a light modulation element array such as a DMD, and in particular to a series of data processing operations from input of drawing data to exposure operation. [Background technology]

[0002] In the manufacturing process of circuit boards, etc., a drawing process (exposure operation) is performed on a board to which a photosensitive material such as photoresist is applied or attached. In the drawing process, pattern data (vector data) sent from a CAD system, etc. is converted into raster data, and the DMD is driven and controlled based on the raster data.

[0003] In the drawing process, multiple exposure operations involving overlapping exposure are performed, and data conversion processing, data transfer, data update processing, etc. are performed accordingly. Since it is necessary to frequently perform data conversion and data updates for huge amounts of data, the data transfer and data conversion processing take time in throughput, which affects the overall system.

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

[0005] [Patent Document 1] Patent No. 4203649 [Patent Document 2] Patent No. 5258226 Summary of the Invention [Problem to be solved by the invention]

[0006] In recent years, there has been a demand for maskless exposure tools to form patterns with higher resolution. However, the resolution is limited by the characteristics and performance of light modulation element arrays such as DMDs.

[0007] Therefore, there is a need to provide an exposure apparatus capable of performing data processing to form patterns with higher resolution. [Means for solving the problem]

[0008] In the present invention, the technical trend is directed to a raster conversion process of vector data that generates raster data based on bit data in a cell unit different from the cell unit (cell size) of each light modulation element.

[0009] An exposure apparatus according to one embodiment of the present invention includes a raster data conversion unit that converts vector data into raster data (here referred to as subdivided raster data) composed of cell units smaller than the projection area of ​​the light modulation elements that constitute the light modulation element array.

[0010] The subdivided raster data can be configured as bit data in which pixel data is arranged in a matrix at data intervals smaller than the data intervals of the bit data corresponding to the cell size of the light modulation element. For example, the raster data conversion unit can generate the subdivided raster data so that the size of the cell unit of the subdivided raster data is 1 / 10 or less of the projection area of ​​the light modulation element.

[0011] The exposure device includes a raster data extraction unit that extracts pixel data corresponding to each light modulation element from the subdivided raster data according to the relative position of the exposure area of ​​the light modulation element array and generates drawing raster data, and an exposure unit that drives and controls each light modulation element based on the generated drawing raster data. For example, the raster data extraction unit can extract pixel data corresponding to the center position of the projection area of ​​the light modulation element during exposure operation.

[0012] The exposure apparatus may further include a raster memory capable of writing the divided raster data. For example, the memory area of ​​the raster memory may be configured to correspond to a band area larger than the exposure area of ​​the light modulation element array.

[0013] The exposure apparatus may include a divided vector data generating unit that divides the vector data according to unit areas defined along the scanning band area of ​​the light modulation element array, and generates divided vector data. The raster data converting unit can convert each of the divided vector data into subdivided raster data. For example, the raster data converting unit can determine the unit areas of the divided vector data according to the size of the cell unit of the subdivided raster data.

[0014] The processing speed of the raster conversion process is affected by the size of the cell unit of the divided raster data. The exposure device can include a divided vector data generating unit that divides the vector data according to unit areas defined along the scanning band area of ​​the light modulation element array and generates divided vector data. For example, the raster data converting unit can convert each of the divided vector data into divided raster data.

[0015] For example, the exposure device is equipped with a raster memory into which the raster data generated for each divided vector data can be written, and the raster data conversion unit can convert the data into raster data depending on the free space in the raster memory (e.g., the free space corresponding to the memory area corresponding to the divided vector data).

[0016] In addition, the memory area of ​​the raster memory can be configured to correspond to a band area larger than the exposure area of ​​the light modulation element array, and data processing in the raster data conversion unit can be easily performed by continuously sending raster data to the raster memory in sequence.

[0017] Another aspect of the present invention is an exposure method in which vector data is converted into subdivided raster data composed of cell units smaller than the projection area of ​​the light modulation element, pixel data corresponding to each light modulation element is extracted from the subdivided raster data according to the relative position of the exposure area of ​​the light modulation element array, drawing raster data is generated, and each light modulation element is driven and controlled based on the generated drawing raster data. Effect of the Invention

[0018] According to the present invention, it is desired to provide an exposure apparatus capable of executing data processing for forming a pattern with higher resolution for a maskless exposure apparatus. [Brief description of the drawings]

[0019] [Figure 1] 1 is a block diagram of an exposure apparatus according to an embodiment of the present invention. [Diagram 2] 11A and 11B are diagrams illustrating a part of a raster conversion process executed in a raster conversion unit. [Diagram 3] 13A and 13B are diagrams illustrating a process of extracting subdivided raster data executed in an extraction unit. [Figure 4] 11 is a flowchart showing the process flow of a raster conversion unit, an extraction unit, and an exposure unit. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] The exposure apparatus according to this embodiment will be described below with reference to the drawings.

[0021] 1 is a block diagram of an exposure apparatus according to the present embodiment. The exposure apparatus 10 is configured as a maskless exposure apparatus capable of forming a pattern on a substrate W such as a printed circuit board. The substrate W is mounted on a stage 50, and the stage 50 can be moved in the main scanning direction (X direction) and the sub-scanning direction (Y direction) by an XY stage mechanism (not shown).

[0022] The exposure apparatus 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., and is arranged side by side at a predetermined interval along the sub-scanning direction (Y direction) (only one exposure head 20 is shown in FIG. 1). Light output from a light source (not shown), such as a laser, is projected onto a substrate W via the illumination optical system, the DMD 30, and the projection optical system 40.

[0023] In DMD 30, in which rectangular micromirrors are arranged two-dimensionally in a matrix, each micromirror is controlled to be turned on and off. Light reflected by the micromirrors becomes pattern light and is guided to projection optical system 40, where it is imaged on the surface of a photosensitive material that is applied to or attached to substrate W. The imaging magnification is determined according to the optical performance of projection optical system 40, and is set to 1x here.

[0024] Exposure apparatus 10 is connected to a CAD system or the like, and a controller 90 controls the operation of exposure apparatus 10. As drawing data sent from the CAD system or the like is input, a series of data processing related to exposure is executed.

[0025] 1, a portion of the configuration of the exposure apparatus 10 is shown grouped by function. The exposure apparatus 10 includes a raster conversion unit 60, an extraction unit 70, and an exposure unit 80.

[0026] The raster conversion unit 60 includes a vector data division unit 62 and a raster data conversion unit 64. The raster conversion unit 60 executes a raster conversion process for converting the drawing data, which is vector data, into raster data. The raster data generated by the raster conversion process is stored in a raster memory 92. The drawing data, which is vector data, may be converted into raster data through an alignment correction process, a coordinate conversion process, and the like.

[0027] The extraction unit 70 includes a raster data extraction unit 72 and an image data memory 74. The extraction unit 70 extracts raster data (drawing raster data) composed of pixels (bits) corresponding to the positions of each micromirror of the DMD 30 from the raster data stored in the raster memory 92. This determines the ON / OFF state of each micromirror of the DMD 30. Hereinafter, the raster data constituting the pattern image formed by the micromirrors of the DMD 30 will be referred to as "screen data" as necessary. The screen data is temporarily stored in the image data memory 74.

[0028] The exposure section 80 includes the above-mentioned exposure head 20, a stage measurement section 82, and a data transfer section 84. Based on stage position information sent from the stage measurement section 82, the data transfer section 84 transfers screen data corresponding to the relative position of the exposure area from the image data memory 74 to the DMD 30. Each micromirror of the DMD 30 is ON / OFF controlled (drive controlled) based on the sent screen data.

[0029] In the exposure operation, as the stage 50 moves along the main scanning direction (X direction), the exposure area, which is the projection region of the DMD 30, moves along the main scanning direction (X direction) relative to the substrate W. Here, the exposure head 20 is disposed so that the exposure area is inclined at a small inclination angle α with respect to the main scanning direction (X direction).

[0030] While the stage 50 moves at a constant speed, a multiple exposure operation (overlapping exposure) is performed according to a predetermined exposure pitch. By performing a multiple exposure operation on each strip-shaped scanning area (hereinafter referred to as a scanning band area), drawing processing is performed on the entire substrate W.

[0031] In the data processing related to a series of exposures, the raster data conversion process of the raster converter 60 and the raster data extraction process of the extractor 70 are executed independently in the exposure apparatus 10. Furthermore, the raster data conversion process of the raster converter 60 is executed according to the processing status of the raster data extraction process of the extractor 70 and the multiple exposure operation of the exposure unit 80.

[0032] Furthermore, the raster data generated by the raster data conversion process of the raster conversion unit 60 is not raster data in which the data interval is determined to match the size of the projection area (microspot area) of each micromirror of the DMD 30, but is configured as raster data (hereinafter referred to as subdivided raster data) in which the data interval is determined in cell size units (pixel size units) that are smaller than the projection area size.

[0033] Hereinafter, the independence (non-coordination) of such data processing and the process of generating the divided raster data will be described with reference to FIGS.

[0034] 2 is a diagram showing a part of the raster conversion process executed in the raster conversion unit 60. Here, the scanning band area by the DMD 30 is indicated by the symbol "BD."

[0035] A unit area is predefined for the scanning band area BD. The unit area represents a data area that becomes one chunk when drawing data (vector data) is partially extracted and divided. The size of the unit area is determined according to the processing speed of the raster conversion process, etc. In FIG. 2, the unit areas defined for the scanning band area BD are represented by symbols VP0 to VPn.

[0036] Drawing data, which is vector data, is divided according to unit areas. In the vector data obtained by division (hereinafter referred to as divided vector data), feature points Bd of the pattern appear on boundary lines (hereinafter also referred to as partitions) L that define the unit areas. Therefore, for the divided vector data of each unit area, the position coordinates (X, Y coordinates) of the feature points Bd located on the boundary lines L are calculated.

[0037] The raster data conversion unit 64 converts the divided vector data into raster data. At this time, as described above, the subdivided raster data is generated, which is bitmap data composed of cell size units smaller than the size of the projection area of ​​the micromirror. Here, the size of each bit data (pixel data) constituting the subdivided raster data is set to be less than one tenth of the size of the projection area of ​​the micromirror.

[0038] Subdivision raster data is generated for each piece of divided vector data, and stored in the raster memory 92. The raster memory 92 here is configured as a buffer memory having a ring buffer function.

[0039] The generated divided raster data is written as necessary in the raster memory 92. The controller 90 controls writing of the divided raster data into the raster memory 92, and writes the divided raster data into the raster memory 92 according to the free space in the raster memory 92.

[0040] FIG. 3 is a diagram showing the process of extracting the divided raster data executed by the extracting unit 70. As shown in FIG.

[0041] The divided raster data is configured as image data in which patterns are integrated in the raster memory 92. As shown in Fig. 3, the memory area of ​​the raster memory 92 corresponds to a band area larger than the size of the exposure area EA of the DMD 30. The divided raster data changes its storage position in the memory area according to the exposure pitch PP. The controller 90 controls the reading of the divided raster data in the raster memory 92.

[0042] Raster data extraction unit 72 extracts pixel data (bit data) corresponding to the position of each micromirror from the divided raster data stored in raster memory 92 according to the relative position of the exposure area of ​​DMD 30. Specifically, it calculates the shot center position CC during the exposure operation of each micromirror, and extracts pixel data (bit data) from the divided raster data corresponding to that position.

[0043] Then, drawing raster data is generated based on bitmap data in which the extracted bit data is arranged according to the micromirror array. As described above, the subdivided raster data is raster data generated at a resolution lower than the screen resolution of the DMD 30, but the resolution of the drawing raster data matches the screen resolution of the DMD 30.

[0044] 3, the shot center position is indicated by the symbol CC, and the extracted divided raster data is indicated by the symbol RM. Note that the shot center position CC and the extracted divided raster data RM are illustrated as dot patterns having a larger cell size unit than the divided raster data BR before extraction, i.e., a larger data interval.

[0045] The extracted divided raster data RM is data that determines the ON / OFF state of the corresponding micromirror. Therefore, the extraction of the divided raster data RM in accordance with the exposure operation leads to the generation of image data of the pattern represented by the micromirrors that constitute the DMD 30, that is, screen data. Figure 3 shows the screen data that is generated sequentially in accordance with the exposure pitch PP.

[0046] Here, the generation of divided vector data and subdivided raster data in the raster conversion unit 60 is executed continuously and repeatedly as a series of data processing operations, while the extraction of subdivided raster data by the extraction unit 70 is executed independently, not in conjunction with the data processing operations in the raster conversion unit 60.

[0047] That is, by temporarily storing the generated subdivided raster data in the raster memory 92, which is a buffer memory, the process of extracting the subdivided raster data and the generation of screen data can be performed independently of the raster conversion process.

[0048] The exposure unit 80 generates screen data, i.e., executes a multiple exposure operation in accordance with the exposure pitch PP. Therefore, the data processing of the extraction unit 70 and exposure unit 80 is data processing that is continuously and repeatedly executed in accordance with the exposure pitch PP. These data processes are performed via the raster memory 92, which is a buffer memory, without being linked to the raster conversion process of the raster conversion unit 60.

[0049] Meanwhile, whether or not data can be written to the raster memory 92 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 executed in accordance with the exposure pitch PP, and the process of extracting the divided raster data creates a state in which the divided raster data can be written in the raster memory 92. The process of generating the divided vector data and the divided raster data is repeatedly performed in accordance with the free space of the raster memory 92.

[0050] As described above, in exposure apparatus 10 of the present embodiment, data processing in raster conversion unit 60 and extraction unit 70 are executed independently via raster memory 92. By dividing the processing contents for a series of exposure-related processes from a functional standpoint and executing the processes repeatedly within the divided processing groups, data processing can be performed effectively while maintaining throughput.

[0051] Furthermore, in this embodiment, the raster conversion unit 60 generates divided vector data to fit the vector data to the unit area BD, and also generates subdivided raster data BR composed of a cell size smaller than the projection area of ​​the micromirror.

[0052] The subdivided raster data corresponding to the shot center position of each micromirror is selected and extracted from the subdivided raster data whose cell size is much smaller than the projection area size of the micromirror of the DMD 30. This makes it possible to appropriately determine the ON / OFF state of each micromirror with respect to the relative position of the exposure area EA (the shot center position of the micromirror), and patterns can be formed with high precision.

[0053] FIG. 4 is a flowchart showing the flow of processing by the raster conversion unit 60, the extraction unit 70, and the exposure unit 80.

[0054] The raster conversion unit 60 repeatedly executes the raster conversion process (S101 to 106) depending on the free space of the raster memory 92. However, here, the unit areas are managed as partition numbers.

[0055] In the extraction unit 70, pixel data (bit data) corresponding to the position of each micromirror is selected from the divided raster data stored in the raster memory 92, and the screen data, that is, the drawing raster data which is bitmap data corresponding to the resolution of the DMD 30, is stored in the image data memory 74 (S201 to S208). However, here, the screen data number is managed as the generated screen number.

[0056] In the exposure section 80, multiple exposure operations are performed in accordance with the readout of the screen data (S301 to S306). However, the timing of the exposure operations according to the exposure pitch is managed as an exposure number.

[0057] With respect to exposure apparatus 10, when attention is focused on a configuration in which raster conversion unit 60 and extraction unit 70 process data in a non-coordinated manner, the configuration may be such that subdivided raster data is not generated. On the other hand, when attention is focused on a configuration in which subdivided raster data is generated, the configuration in which raster conversion unit 60 and extraction unit 70 do not need to process data in a non-coordinated manner.

[0058] The exposure apparatus 10 can be configured to split the pattern light of the light modulation element array along the sub-scanning direction by a splitting optical system (branching optical system), and scan along different scanning bands. The above-mentioned data processing can also be applied to such an exposure apparatus 10. [Explanation of symbols]

[0059] 10 Exposure equipment 30 DMD 60 Raster conversion section 70 Extraction part 80 Exposure section

Claims

1. a raster data conversion unit that converts the vector data into divided raster data composed of cell units smaller than the projection area of ​​the light modulation elements that constitute the light modulation element array; a raster data extraction unit that extracts pixel data corresponding to each light modulation element from the divided raster data in accordance with a relative position of an exposure area of ​​the light modulation element array, and generates drawing raster data; an exposure unit that drives and controls each light modulation element based on the generated drawing raster data; An exposure apparatus comprising:

2. A raster memory capable of writing the divided raster data is further provided, 2. An exposure apparatus according to claim 1, wherein the memory area of ​​the raster memory corresponds to a band area larger than an exposure area of ​​the light modulation element array.

3. 2. An exposure apparatus according to claim 1, wherein the size of the cell unit of the divided raster data is 1 / 10 or less of the projection area of ​​a light modulation element.

4. A divided vector data generating unit is further provided for dividing the vector data in accordance with a unit area defined along a scanning band area of ​​the light modulation element array, and generating divided vector data; 2. The exposure apparatus according to claim 1, wherein the raster data conversion unit converts each of the divided vector data into the subdivided raster data.

5. The vector data is converted into subdivided raster data composed of cell units smaller than the projection area of ​​the light modulation element; extracting pixel data corresponding to each light modulation element from the divided raster data in accordance with a relative position of an exposure area of ​​the light modulation element array to generate drawing raster data; An exposure method characterized in that each light modulation element is driven and controlled based on the generated drawing raster data.

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