Exposure apparatus and exposure method

Abstract

The object of this invention is to provide an exposure apparatus capable of performing data processing to form higher resolution patterns for a maskless exposure apparatus. The solution is an exposure apparatus 10 including a grid conversion unit 60. The grid conversion unit 60 generates decomposed vector data from vector data according to unit regions, and simultaneously generates subdivided grid data composed of grid sizes smaller than the projection area of ​​the micromirror.

Description

Technical Field

[0001] This invention relates to a maskless exposure apparatus that uses light modulation elements such as a digital micromirror device (DMD) to form patterns, and particularly to a series of data processing steps from the input of graphic data to the exposure operation. Prior Technology

[0002] In the manufacturing process of circuit boards, etc., patterning (exposure operation) is applied to the substrate coated or attached with photosensitive materials such as photoresist. In patterning, pattern data (vector data) sent from computer-aided design (CAD) systems, etc., is converted into mesh data, and a digital micromirror device is driven and controlled based on the mesh data.

[0003] In graphics processing, multiple exposure operations involving overlapping exposures are performed, followed by data conversion, data transfer, and data update processes. Because these frequent data conversions and updates involve large volumes of data, and both data transfer and conversion processes require time, this significantly impacts production output.

[0004] To reduce data processing, for example, only a portion of the vector data is extracted, and the extracted vector data is converted into grid data before driving and controlling the digital micromirror device (see Patent Document 1). Furthermore, multiple memory units (the first to the Nth memory units) are prepared for the grid data, and the grid data stored in each memory unit is sequentially moved to adjacent memory units while simultaneously driving and controlling the digital micromirror device (see Patent Document 2). [Preliminary Technology Documents] [Patent Literature]

[0005] [Patent Document 1] Japanese Patent No. 4203649 [Patent Document 2] Japanese Patent No. 5258226 Summary of the Invention

[0006] [The problem the invention aims to solve]

[0007] In recent years, there has been a demand for creating higher resolution patterns using maskless exposure devices. However, resolution is limited by the characteristics and performance of optical modulation element arrays such as digital micromirror devices.

[0008] Therefore, an exposure device is needed that can perform data processing to form patterns with higher resolution. [Methods used to solve problems]

[0009] In this invention, the trend in the mesh transformation processing of vector data is to use mesh transformation processing to generate mesh data based on bit data of grid units (grid size) that are different from the grid units (grid size) of each optical modulation element.

[0010] The present invention provides an exposure apparatus including a grid data conversion unit that converts vector data into grid data composed of cell units (referred to herein as subdivided grid data), wherein the size of the cell unit is smaller than the projected area of ​​the light modulation element constituting the light modulation element array.

[0011] The subdivided mesh data can be configured as bit data, wherein the pixel data is arranged in a matrix with a data spacing smaller than that of the bit data corresponding to the grid size of the light modulator. For example, the mesh data conversion unit can generate subdivided mesh data such that the size of the grid unit of the subdivided mesh data is less than one-tenth of the projection area of ​​the light modulator.

[0012] The exposure apparatus then includes a grid data extraction unit and an exposure unit. The grid data extraction unit extracts pixel data corresponding to each optical modulation element from a subdivided grid data according to the relative positions of the exposure areas of the optical modulation element array, and generates graphic grid data. The exposure unit drives and controls each optical modulation element based on the generated graphic grid data. For example, the grid data extraction unit can extract pixel data based on the center position of the projection area of ​​the optical modulation element during the exposure operation.

[0013] The exposure apparatus can further include a grid memory, capable of writing subdivided grid data. For example, the memory area of ​​the grid memory can be configured as a strip area larger than the exposure area of ​​the light modulation element array.

[0014] The exposure apparatus may further include a vector decomposition data generation unit, which decomposes vector data according to a unit region defined along the scanning strip region of the light modulation element array, and generates decomposed vector data. A mesh data conversion unit can convert each of the decomposed vector data into a subdivided mesh data. For example, the mesh data conversion unit can define the unit region of the decomposed vector data according to the size of the grid units of the subdivided mesh data.

[0015] Mesh conversion processing affects its processing speed by considering the size of the grid units in the subdivided mesh data. The exposure apparatus may further include a decomposed vector data generation unit that decomposes the vector data according to a unit region defined along the scanning strip area of ​​the light modulation element array and generates decomposed vector data. For example, the mesh data conversion unit can convert each decomposed vector data into subdivided mesh data.

[0016] For example, the exposure apparatus includes a grid memory capable of writing grid data generated from each decomposed vector data, and the grid data conversion unit can convert the grid data according to the spatial state of the grid memory (e.g., the corresponding spatial capacity of the memory area based on the decomposed vector data).

[0017] Furthermore, the memory area of ​​the grid memory can be configured as a strip area larger than the exposure area of ​​the light modulation element array, and the data processing in the grid data conversion unit can easily continue to send the grid data to the grid memory in sequence.

[0018] Another aspect of the exposure method of the present invention involves converting vector data into subdivided grid data composed of lattice units, wherein the size of the lattice unit is smaller than the projected area of ​​the light modulation element; extracting pixel data corresponding to each light modulation element from the subdivided grid data according to the relative position of the exposure area of ​​the light modulation element array, and generating graphic grid data; and driving and controlling each light modulation element based on the generated graphic grid data. [Invention Benefits]

[0019] According to the present invention, there is a need to provide an exposure apparatus capable of performing data processing to form higher resolution patterns for a maskless exposure apparatus. Simple Explanation of the Diagram

[0020] Figure 1 is a block diagram of the exposure apparatus of this embodiment. Figure 2 is a schematic diagram of a portion of the mesh transformation process performed in the mesh transformation unit. Figure 3 is a schematic diagram of the subdivided grid data extraction process performed in the extraction unit. Figure 4 is a flowchart showing the processing flow of the mesh conversion section, extraction section, and exposure section. Implementation

[0021] [The form in which the invention is carried out]

[0022] The exposure apparatus of this embodiment will be described below with reference to the figures.

[0023] Figure 1 is a block diagram of the exposure apparatus of this embodiment. The exposure apparatus 10 is configured as a maskless exposure apparatus, capable of forming patterns on a substrate W such as a printed circuit board. The substrate W is mounted on a platform 50, which is movable in the main scanning direction (X direction) and the sub-scanning direction (Y direction) by means of an XY platform mechanism (not shown).

[0024] The exposure apparatus 10 includes a plurality of exposure heads 20, comprising an illumination optics system (not shown), a digital micromirror device (DMD) 30, and a projection optics system 40, etc., arranged at predetermined intervals along the sub-scanning direction (Y direction) (only one exposure head 20 is shown in Figure 1). The light emitted from a light source such as a laser (not shown) is projected onto the substrate W via the illumination optics system, the digital micromirror device 30, and the projection optics system 40.

[0025] In a digital micromirror device 30, which arranges rectangular micromirrors in a two-dimensional matrix, the individual micromirrors are controlled to turn on and off. The light reflected by the micromirrors is converted into patterned light and guided by a projection optics system 40, and imaged onto the surface of a photosensitive material coated or attached to a substrate W. The imaging magnification depends on the optical performance of the projection optics system 40, and is set to 1x in this paper.

[0026] The exposure apparatus 10 is connected to a computer-aided design (CAD) system, etc., and the controller 90 controls the operation of the exposure apparatus 10. When graphic data sent from the computer-aided design system, etc., is input, a series of data processing related to exposure is performed.

[0027] Figure 1 shows a portion of the structure of the exposure apparatus 10 grouped according to function. The exposure apparatus 10 includes a grid conversion unit 60, an extraction unit 70, and an exposure unit 80.

[0028] The mesh conversion unit 60 includes a vector data decomposition unit 62 and a mesh data conversion unit 64. Mesh conversion processing is performed in the mesh conversion unit 60 to convert vector-based graphic data into mesh data. The mesh data generated by the mesh conversion processing is stored in the mesh memory 92. Furthermore, vector-based graphic data can also be converted into mesh data through alignment correction processing, coordinate transformation processing, etc.

[0029] The extraction unit 70 includes a grid data extraction unit 72 and an image data memory 74. In the extraction unit 70, grid data (graphic grid data) composed of pixels (bits) corresponding to the positions of each micromirror of the digital micromirror device 30 is extracted from the grid data stored in the grid memory 92. This defines the on / off state of each micromirror of the digital micromirror device 30. In the following text, the grid data constituting the pattern image formed by the micromirrors of this digital micromirror device 30 will be referred to as "graphic data" as needed. The graphic data is temporarily stored in the image data memory 74.

[0030] The exposure unit 80 includes the aforementioned exposure head 20, platform measurement unit 82, and data transmission unit 84. The data transmission unit 84 transmits image data corresponding to the relative position of the exposure area from the image data memory 74 to the digital micromirror device 30 based on platform position information received from the platform measurement unit 82. Each micromirror in the digital micromirror device 30 performs on / off control (drive control) based on the received image data.

[0031] During the exposure operation, as the platform 50 moves along the main scanning direction (X direction), the exposure area (i.e., the projection area of ​​the digital micromirror device 30) moves relative to the substrate W along the main scanning direction (X direction). Here, the exposure head 20 is configured such that the exposure area is tilted by only a small tilt angle α relative to the main scanning direction (X direction).

[0032] When platform 50 moves at a certain speed, it performs multiple exposure operations (overlapping exposures) according to a predefined exposure pitch. By performing multiple exposure operations on separate strip-shaped scanning areas (hereinafter referred to as scanning strip areas), the entire substrate W is patterned.

[0033] In a series of exposure-related data processing steps, within the exposure apparatus 10, the grid data conversion processing of the grid conversion unit 60 and the grid data extraction processing of the extraction unit 70 are performed independently. Furthermore, the grid data processing of the grid conversion unit 60 is performed based on the grid data extraction processing of the extraction unit 70 and the processing status of the multiple exposure operation of the exposure unit 80.

[0034] Furthermore, the grid data generated by the grid data conversion process of the grid conversion unit 60 is not grid data that defines the data interval according to the size of the projection area (tiny light spot area) of each micromirror of the digital micromirror device 30, but is configured to define the data interval in a grid size unit (pixel size unit) smaller than the size of the projection area (hereinafter referred to as subdivided grid data).

[0035] The independence of this data processing and the generation process of subdivided grid data are explained below using Figures 2 and 3.

[0036] Figure 2 is a schematic diagram of a portion of the mesh conversion process performed in the mesh conversion unit 60. Here, the scanned strip area scanned by the digital micromirror device 30 is represented by the element symbol "BD".

[0037] A unit region is predefined for the scanned strip region BD. The unit region represents a portion of the extracted graphic data (vector data), a data area divided into blocks during data partitioning. The size of the unit region is defined based on factors such as the processing speed of the mesh transformation. In Figure 2, the unit regions defined in the scanned strip region BD are represented by element symbols VP0 to VPn.

[0038] Graphical data in vector form is decomposed based on unit regions. In the vector data obtained through decomposition (hereinafter referred to as decomposed vector data), the feature points Bd of the pattern are presented on the boundary lines (hereinafter also referred to as partitions) L that define the unit regions. Therefore, for the vector data of each unit region, the position coordinates (X, Y coordinates) of the feature points Bd located on the boundary line L are calculated.

[0039] The mesh data conversion unit 64 converts the decomposed vector data into mesh data. At this time, as described above, subdivided mesh data is generated, that is, raster data composed of grid-size units smaller than the size of the micromirror's projection area. In this paper, the size of each bit data (pixel data) constituting the subdivided mesh data is defined as less than one-tenth of the size of the micromirror's projection area.

[0040] Each decomposed vector data generates subdivided mesh data and is stored in mesh memory 92. Mesh memory 92 is configured as a buffer memory with circular buffering function.

[0041] In grid memory 92, the generated subdivision grid data is written as needed. Controller 90 controls the writing of subdivision grid data to grid memory 92, and writes the subdivision grid data to grid memory 92 according to the space state of grid memory 92.

[0042] Figure 3 is a schematic diagram of the subdivided grid data extraction process performed in the extraction unit 70.

[0043] The subdivided grid data constitutes image data that integrates patterns in the grid memory 92. As shown in Figure 3, the memory area of ​​the grid memory 92 corresponds to a strip area larger than the exposure area EA of the digital micromirror device 30. The storage location of the memory area changes according to the exposure pitch PP. The controller 90 performs control over reading the subdivided grid data from the grid memory 92.

[0044] In the grid data extraction unit 72, pixel data (bit data) corresponding to each micromirror position is extracted from the subdivided grid data stored in the grid memory 92, based on the relative position of the exposure area of ​​the digital micromirror device 30. Specifically, the illumination center position CC during the exposure operation of each micromirror is calculated, and pixel data (bit data) in the subdivided grid data is extracted accordingly.

[0045] Then, graphic grid data is generated based on the bitmap data, and the bit data extracted from the bitmap data is configured according to the micromirror arrangement. As mentioned above, although the subdivided grid data is generated at a resolution lower than the screen resolution of the digital micromirror device 30, the resolution of the graphic grid data is consistent with the screen resolution of the digital micromirror device 30.

[0046] In Figure 3, the irradiation center position is represented by the element symbol CC, and the extracted subdivision grid data is represented by the element symbol RM. Furthermore, the irradiation center position CC and the extracted subdivision grid data RM are illustrated as a dot pattern with a larger grid size unit (i.e., larger data interval) than the original subdivision grid data BR.

[0047] The extracted subdivided grid data RM defines the on / off state of the corresponding micromirrors. Therefore, by extracting the subdivided grid data RM according to the exposure operation, image data (i.e., graphic data) representing the pattern constituted by the micromirrors of the digital micromirror device 30 can be generated. Figure 3 shows the graphic data generated sequentially according to the exposure pitch PP.

[0048] In this paper, the generation of decomposed vector data and subdivided mesh data in the mesh conversion unit 60 is performed continuously and repeatedly as a series of data processing steps. On the other hand, the extraction of subdivided mesh data in the extraction unit 70 is not performed in conjunction with the data processing in the mesh conversion unit 60, but is performed independently.

[0049] In other words, by temporarily storing the generated subdivision mesh data in mesh memory 92, which serves as a buffer memory, the extraction and processing of subdivision mesh data and the generation of map data can be performed independently of mesh transformation processing.

[0050] The exposure unit 80 performs multiple exposure operations according to the generation of image data (i.e., exposure pitch PP). Therefore, the data processing of the extraction unit 70 and the exposure unit 80 is data processing that is continuously and repeatedly executed according to the exposure pitch PP. This data processing is performed via the grid memory 92, which is a buffer memory, and is not related to the grid conversion processing of the grid conversion unit 60.

[0051] However, whether data can be written to the grid memory 92 depends on the spatial state of the grid memory 92. As mentioned above, the data processing of the extraction unit 70 and the exposure unit 80 is performed according to the exposure pitch PP. By extracting the subdivision grid data, a state is generated that allows the subdivision grid data to be written into the grid memory 92. The decomposition vector data and the generation of subdivision grid data are repeatedly performed according to the spatial state of the grid memory 92.

[0052] As explained above, in the exposure apparatus 10 of this embodiment, data processing in the grid conversion unit 60 and the extraction unit 70 is performed independently via the grid memory 92. From a functional point of view, the processing content is differentiated for a series of exposure-related processes, and by repeatedly executing them in separate processing groups, data processing can be effectively performed while maintaining production volume.

[0053] Furthermore, in this embodiment, the grid conversion unit 60 generates decomposed vector data from the vector data according to the unit region BD. In addition, it generates subdivided grid data BR composed of grid size, wherein the size of the grid size is smaller than the projection area of ​​the micromirror.

[0054] From the subdivided grid data whose grid size is much smaller than the projection area size of the micromirrors in the digital micromirror device 30, subdivided grid data that matches the illumination center position of each micromirror is selected and extracted. Therefore, the on / off state of each micromirror can be appropriately defined according to the relative position of the exposure area EA (the illumination center position of the micromirror), thereby forming a pattern with high precision.

[0055] Figure 4 is a flowchart showing the processing flow of the mesh conversion unit 60, the extraction unit 70, and the exposure unit 80.

[0056] In the grid conversion unit 60, the grid conversion process (steps S101 to S106) is repeatedly executed according to the spatial state of the grid memory 92. However, here, the unit area is managed as a partition number.

[0057] In the extraction unit 70, pixel data (bit data) corresponding to each micromirror position is selected from the subdivided grid data stored in the grid memory 92. The image data (i.e., the graphic grid data that is a raster image corresponding to the resolution of the digital micromirror device 30) is stored in the image data memory 74 (steps S201 to S208). However, here, the number of the image data is managed as the generated image number.

[0058] In the exposure unit 80, multiple exposure operations are performed based on the reading of the drawing data (steps S301 to S306). However, the time for performing the exposure operation according to the exposure pitch is managed as an exposure number.

[0059] Regarding the exposure apparatus 10, if the structure of the grid conversion unit 60 and the extraction unit 70 for processing data in a non-linked manner is considered, a structure that does not generate finely subdivided grid data may also be adopted. On the other hand, if the structure of generating finely subdivided grid data is considered, a structure in which the grid conversion unit 60 and the extraction unit 70 process data in a non-linked manner may not be adopted.

[0060] Regarding the exposure apparatus 10, a structure can be adopted in which patterned light from an array of light modulation elements branched along the sub-scanning direction by a split optical system (branching optical system) and scanned along their respective distinct scanning bands. In such an exposure apparatus 10, the aforementioned data processing can also be applied.

[0061] 10: Exposure device 20: Exposure Head 30: Digital Microscope Device 40: Projection Optical System 50: Platform 60: Mesh Conversion Department 62: Vector Data Decomposition Section 64: Grid Data Conversion Department 70: Extraction Department 72: Grid Data Extraction Department 74: Image Data Memory 80: Exposure Department 82: Platform Measurement Department 84: Data Transmission Department 90: Controller 92: Grid Memory BD: Scanning strip region (unit area) Bd: Feature point BR: Subdivided Grid Data CC: Center of Irradiation EA: Exposure Zone L: Boundary line PP: Exposure pitch RM: Extracted subdivided grid data S101, S102, S103, S104, S105, S106: Steps S201, S202, S203, S204, S205, S206, S207, S208: Steps S301, S302, S303, S304, S305, S306: Steps VP0, VP1, VP2, VPn: Unit regions W: substrate

[0062] none

Claims

1. An exposure apparatus, comprising: The decomposed vector data generation unit decomposes the vector data into unit regions, defined as continuously arranged along the relative movement direction of the exposure area of ​​the light modulation element array, for the scanning strip region where the exposure area moves relatively. The mesh data conversion unit converts the decomposed vector data into subdivided mesh data composed of grid units, the size of which is smaller than the projected area of ​​the light modulation elements constituting the light modulation element array. The mesh data extraction unit extracts pixel data corresponding to each light modulation element from the subdivided mesh data according to the relative position of the exposure area of ​​the light modulation element array and generates graphic mesh data. The exposure unit drives and controls each light modulation element based on the generated graphic mesh data. The unit region is defined according to the size of the grid units of the subdivided mesh data.

2. The exposure apparatus as described in claim 1 further includes: Grid memory is capable of storing the subdivided grid data; The grid data extraction unit extracts pixel data corresponding to each light modulation element from the subdivided grid data stored in the grid memory according to the relative position of the exposure area of ​​the light modulation element array, and generates graphic grid data; wherein the memory area of ​​the grid memory is a memory area equivalent to a larger area than the exposure area of ​​the light modulation element array in the scan strip area.

3. The exposure apparatus as described in claim 1, wherein the size of the grid unit of the subdivided grid data is less than one-tenth of the projection area of ​​the light modulation element.

4. The exposure apparatus as described in claim 1, wherein the width of the unit region along the relative movement direction of the exposure area is smaller than the width of the exposure area along the relative movement direction, and larger than the exposure pitch.

5. An exposure method comprising the following steps: For a scan strip region of an exposure area of ​​an array of light modulators that is relatively moved, in order to decompose vector data, decompose the vector data according to a unit region defined as being continuously arranged along the relative movement direction of the exposure area and corresponding to the size of a grid unit of the subdivided grid data; Convert the decomposed vector data generated by decomposing the vector data into subdivided grid data composed of grid units, the size of which is smaller than the projected area of ​​the light modulator; Extract pixel data corresponding to each of the light modulators from the subdivided grid data according to the relative position of the exposure areas of the array of light modulators, and generate graphic grid data; and Drive and control each of the light modulators based on the generated graphic grid data.

6. The exposure method as described in request item 5, wherein, The subdivided grid data is stored in a grid memory having a memory area that is larger than the exposure area of ​​the light modulation element array in the scan strip region; depending on the relative position of the exposure area of ​​the light modulation element array, pixel data corresponding to each light modulation element is extracted from the subdivided grid data stored in the grid memory, and graphic grid data is generated.

7. The exposure method as described in request item 6, wherein, The spatial state of the grid memory is converted into the subdivided grid data.

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