KR20240078331A - Position detection apparatus, drawing apparatus, position detection method, and program recorded on a recording medium - Google Patents

Abstract

The storage unit 111 of the position detection device stores a template group. The template group includes two or more templates among a reference template that is a template generated from reference CAD data, which is the CAD data of the pattern, and a plurality of offset templates that are templates in which the line widths of pattern elements included in the reference template are changed, respectively. . The template selection unit 114 performs pattern matching on the captured image acquired by the imaging unit 3 using each template included in the template group, and selects an applied template from the template group based on the matching score. . The position detection unit 115 detects the position of the substrate based on the result of pattern matching using the template applied to the captured image. Thereby, the position of the substrate can be detected with high precision.

Description

Position detection device, drawing device, position detection method, and program recorded on recording medium {POSITION DETECTION APPARATUS, DRAWING APPARATUS, POSITION DETECTION METHOD, AND PROGRAM RECORDED ON A RECORDING MEDIUM}

The present invention relates to technology for detecting the position of a substrate.

[Reference to related applications]

This application claims the benefit of priority from Japanese patent application JP2022-188314 filed on November 25, 2022, and all disclosures of this application are hereby incorporated by reference.

Conventionally, patterns are drawn by irradiating light to a photosensitive material formed on a semiconductor substrate, a printed circuit board, or a glass substrate for an organic EL display device or liquid crystal display device (hereinafter referred to as a “substrate”). In a drawing device that performs such drawing, an alignment process is performed to automatically adjust the drawing position of the pattern by detecting the position of the alignment mark formed on the substrate.

Recently, in drawing for printed circuit boards, there is a need to reduce the space for arranging alignment marks in order to increase the number of pieces that can be taken from one board. Therefore, it is practiced to use a part of the pattern on the substrate as an alignment mark, rather than forming a mark dedicated to alignment on the substrate.

For example, in the exposure apparatus of Japanese Patent Application Publication No. 2013-171988 (document 1), in an image obtained by imaging a pattern on a substrate, a part of the pattern is a reference mark model (i.e., template) used in the alignment process. ) and is registered in advance. Then, when a substrate to be exposed is brought into the exposure apparatus, a part of the pattern on the substrate is imaged by a camera, pattern matching is performed between the obtained image and the reference mark model, and alignment processing of the substrate is performed.

On the other hand, in Japanese Patent Laid-Open No. 2000-236007 (Document 2), in automatic measurement of a pattern in a scanning electron microscope, pattern data of an arbitrary area is input from CAD data, and pattern outline edge data is obtained from the pattern data. A technology to generate template edge data by extracting is proposed.

However, the line width of the pattern actually formed on the substrate may be thicker or thinner than the line width specified in the CAD data depending on the characteristics of the device forming the pattern. Therefore, when template matching is performed using a template according to CAD data as in Document 2, the line width of the pattern in the template and the line width of the pattern previously formed on the substrate are different, so the matching score is lowered and the substrate is damaged. There is a risk that position detection accuracy will decrease. Also, when the matching score is low, it is conceivable that the operator changes the line width of the pattern in the template little by little and repeats trial and error until the matching score increases to a certain extent, but this work requires a lot of time. .

The present invention is aimed at a position detection device that detects the position of a substrate, and aims to detect the position of the substrate with high precision.

Aspect 1 of the present invention is a position detection device for detecting the position of a substrate, wherein the position detection device includes an imaging unit for imaging a portion of a pattern previously formed on the upper surface of a substrate, and a reference that is CAD data of the pattern. a storage unit that stores a template group including two or more templates among a reference template that is a template generated from CAD data and a plurality of offset templates that are templates in which line widths of pattern elements included in the reference template are respectively changed; a template selection unit that performs pattern matching using each template included in the template group on the captured image acquired by the unit and selects an application template from the template group based on a matching score; and a position detection unit that detects the position of the substrate based on a result of pattern matching using an applied template.

According to the present invention, the position of the substrate can be detected with high precision.

Aspect 2 of the present invention is the position detection device of Aspect 1, wherein pattern matching by the template selection unit is performed using edges of pattern elements included in the application template and the captured image, respectively.

Aspect 3 of the present invention is the position detection device of Aspect 1 or 2, wherein the position detection device further includes a template creation unit that generates the reference template by selecting a template area of a predetermined size from the reference CAD data and rasterizing it. Equipped with

Aspect 4 of the present invention is the position detection device of Aspect 3, wherein the template creation unit selects and rasterizes the template areas from a plurality of offset CAD data in which the line widths of the patterns of the reference CAD data are respectively changed, thereby rasterizing the plurality of template areas. Create an offset template.

Aspect 5 of the present invention is the position detection device of Aspect 1 or 2 (either one of Aspects 1 to 4 may be used), wherein the position detection device is selected by the template selection unit for each of a predetermined number of substrates. An additional display unit is provided to display the type of applied template.

Aspect 6 of the present invention is the position detection device of Aspect 1 or 2 (either one of Aspects 1 to 5 may be used), wherein the position detection device uses each template included in the template group by the template selection unit. Based on the result of pattern matching, a template group change unit is additionally provided to generate a new offset template and add it to the template group.

Aspect 7 of the present invention is the position detection device of Aspect 1 or 2 (either one of Aspects 1 to 6 may be used), wherein a plurality of matching areas are set on the substrate, where pattern matching by the position detection unit is performed, respectively. and the template used for pattern matching in one matching area among the plurality of matching areas is selected by the template selection unit for two or more matching areas other than the one matching area among the plurality of matching areas. Based on the selected two or more applied templates, a template is selected from the template group corresponding to the one matching area.

Aspect 8 of the present invention is the position detection device of Aspect 1 or 2 (either of Aspects 1 to 7 may be used), wherein a lower layer pattern located below the pattern is previously formed on the upper surface of the substrate, The pattern is included in the range of the depth of focus of the imaging unit, and the lower layer pattern is not included.

Aspect 9 of the present invention is a drawing device that draws a pattern by irradiating light to a substrate, wherein the drawing device includes the position detection device of Aspect 1 or 2 (it may be any of Aspects 1 to 8), and a stage that holds a substrate, a drawing head that irradiates modulated light to the upper surface of the substrate, and a scanning mechanism that moves the stage relative to the drawing head in a scanning direction parallel to the upper surface of the substrate; A drawing control unit that controls the drawing head and the scanning mechanism based on the position of the substrate detected by the position detection device, thereby executing drawing on the substrate moving relative to the drawing head in the scanning direction. Equipped with

Aspect 10 of the present invention is a position detection method for detecting the position of a substrate, the position detection method comprising: a) a step of imaging a part of a pattern previously formed on the upper surface of a substrate; b) CAD of the pattern A process of preparing a template group including two or more templates among a reference template, which is a template generated from reference CAD data as data, and a plurality of offset templates, which are templates that each change the line width of a pattern element included in the reference template; c) performing pattern matching using each template included in the template group on the captured image acquired in step a) and selecting an applicable template from the template group based on the matching score; d) imaging and a step of detecting the position of the substrate based on a result of pattern matching using the application template for an image.

Aspect 11 of the present invention is a program recorded on a recording medium that detects the position of a substrate, wherein the program is executed by a computer, thereby performing the following steps: a) imaging a portion of a pattern previously formed on the upper surface of the substrate; , b) a template including two or more templates among a reference template that is a template generated from reference CAD data, which is the CAD data of the pattern, and a plurality of offset templates that are templates in which the line widths of pattern elements included in the reference template are changed, respectively. a step of preparing a group; c) performing pattern matching using each template included in the template group on the captured image acquired in step a) above, and selecting an applied template from the template group based on the matching score; A process and d) a process of detecting the position of the substrate based on a result of pattern matching using the application template for the captured image are performed.

The above-described object and other objects, features, aspects and advantages will become clear from the detailed description of the present invention below with reference to the accompanying drawings.

Fig. 1 is a perspective view showing a drawing device according to one embodiment.
Figure 2 is a diagram showing the configuration of a computer.
Figure 3 is a block diagram showing the function of the control unit.
Fig. 4 is a diagram showing an example of a reference template.
Fig. 5 is a diagram showing an example of an offset template.
Fig. 6 is a diagram showing an example of an offset template.
Fig. 7 is a diagram showing an example of the flow of pattern drawing on a substrate.
Figure 8 is a block diagram showing the functions of the control unit.

Fig. 1 is a perspective view showing a drawing device 1 according to an embodiment of the present invention. The drawing device 1 is a direct drawing device that irradiates spatially modulated approximately beam-like light to a photosensitive material on the substrate 9 and scans the irradiated area of the light on the substrate 9 to draw a pattern. In Fig. 1, three directions orthogonal to each other are indicated by arrows as the X direction, Y direction, and Z direction. In the example shown in FIG. 1, the X direction and Y direction are horizontal directions perpendicular to each other, and the Z direction is a vertical direction. The same applies to other drawings.

The substrate 9 is, for example, a plate-shaped member that has a substantially rectangular shape when viewed from the top. The board 9 is, for example, a multilayer printed wiring board (hereinafter simply referred to as a “printed board”). In this embodiment, a circuit pattern formed of copper (Cu) or the like is previously formed on the upper surface 91 of the substrate 9, and a resist film formed of a photosensitive material is formed on the circuit pattern. Then, in the drawing device 1, a solder pattern is drawn (that is, formed) on the resist film of the substrate 9. The solder pattern is drawn on the circuit pattern described above in accordance with the circuit pattern. Additionally, no alignment mark dedicated to the position detection process (i.e., alignment process) described later is formed on the substrate 9.

In the following description, the pattern (i.e., circuit pattern) previously formed on the upper surface 91 of the substrate 9 is also called the “first pattern.” In addition, the pattern (namely, solder pattern) scheduled to be drawn on the upper surface 91 of the substrate 9 in the drawing device 1 is also called a “second pattern.” Additionally, the type and shape of the substrate 9 may be changed in various ways. In addition, the pattern drawn on the substrate 9 by the drawing device 1 is not limited to the solder pattern and may be changed in various ways.

As shown in FIG. 1 , the drawing device 1 includes a stage 21, a stage moving mechanism 22, an imaging unit 3, a drawing unit 4, and a computer 100. The stage 21 is a substantially flat substrate holding portion that holds the horizontal substrate 9 from below below the imaging section 3 and the drawing section 4 (i.e., on the (-Z) side). . The stage 21 is, for example, a vacuum chuck that adsorbs and holds the lower surface of the substrate 9. The stage 21 may have a structure other than a vacuum chuck, and may be, for example, a mechanical chuck. The upper surface 91 of the substrate 9 placed on the stage 21 is substantially perpendicular to the Z direction and substantially parallel to the X and Y directions.

The stage moving mechanism 22 moves the stage 21 relative to the imaging unit 3 and the drawing unit 4 in a horizontal direction (i.e., a direction substantially parallel to the upper surface 91 of the substrate 9). Shiki is a moving device. The stage moving mechanism 22 includes a first moving mechanism 23 and a second moving mechanism 24. The second moving mechanism 24 moves the stage 21 linearly in the X direction along the guide rail. The first moving mechanism 23 moves the stage 21 linearly in the Y direction along the guide rail together with the second moving mechanism 24. The driving source of the first moving mechanism 23 and the second moving mechanism 24 is, for example, a linear servo motor or a motor mounted on a ball screw. The structures of the first moving mechanism 23 and the second moving mechanism 24 may be changed in various ways.

In the drawing device 1, a stage rotation mechanism that rotates the stage 21 around a rotation axis extending in the Z direction may be provided. Additionally, a stage elevating mechanism that moves the stage 21 in the Z direction may be provided in the drawing device 1. As a stage rotation mechanism, for example, a servo motor can be used. As a stage elevating mechanism, for example, a linear servo motor can be used. The structures of the stage rotation mechanism and the stage elevating mechanism may be changed in various ways.

The imaging unit 3 is provided with a plurality of imaging heads 31 (two in the example shown in FIG. 1) arranged in the X direction. Each imaging head 31 is supported above the stage 21 and the stage moving mechanism 22 by a door-shaped head support portion 30 formed across the stage 21 and the stage moving mechanism 22. . Among the two imaging heads 31, one imaging head 31 is fixed to the head support part 30, and the other imaging head 31 is movable in the X direction on the head support part 30. Thereby, the distance in the X direction between the two imaging heads 31 can be changed. Additionally, the number of imaging heads 31 in the imaging unit 3 may be 1 or 3 or more.

Each imaging head 31 is a camera equipped with an imaging sensor and an optical system (not shown). Each imaging head 31 is, for example, an area camera that acquires two-dimensional images. The imaging sensor includes, for example, imaging elements such as a plurality of CCDs (Charge Coupled Devices) arranged in a matrix. In each imaging head 31, reflected light of illumination light (for example, infrared light) guided from a light source not shown to the upper surface 91 of the substrate 9 is guided to the imaging sensor through an optical system. The imaging sensor receives reflected light from the upper surface 91 of the substrate 9 and acquires an image of a substantially rectangular imaging area. As the light source, various light sources such as LED (Light Emitting Diode) can be used. Additionally, each imaging head 31 may be a different type of camera, such as a line camera.

The drawing unit 4 is provided with a plurality of drawing heads 41 arranged in the X direction and/or Y direction. In the example shown in FIG. 1, six drawing heads 41 are arranged in a substantially straight line in the X direction. Each drawing head 41 is supported above the stage 21 and the stage moving mechanism 22 by a door-shaped head support portion 40 formed across the stage 21 and the stage moving mechanism 22. . The head support portion 40 is disposed on the (+Y) side of the head support portion 30 of the imaging unit 3. Additionally, the number of drawing heads 41 of the drawing unit 4 may be changed as appropriate. For example, the number of drawing heads 41 may be one or two or more.

Each drawing head 41 includes a light source (not shown), an optical system, and a spatial light modulation element. As spatial light modulation elements, various elements such as DMD (Digital Micro Mirror Device) and GLV (Grating Light Valve) (registered trademark of Silicon Light Machines (Sunnyvale, California)) are used. possible. As a light source, various light sources such as LD (Laser Diode) can be used. The plurality of drawing heads 41 have substantially the same structure.

In the drawing device 1, light modulated (i.e., spatial light modulated) from the plurality of drawing heads 41 of the drawing unit 4 is irradiated onto the upper surface 91 of the substrate 9, while a stage moving mechanism is used. The substrate 9 is moved in the Y direction by (22). As a result, the area irradiated with light from the plurality of drawing heads 41 is scanned in the Y direction on the substrate 9, and the pattern on the substrate 9 is drawn. In the following description, the Y direction is also called the “scanning direction” and the X direction is also called the “width direction.” The stage moving mechanism 22 is a scanning mechanism that moves the irradiated area of light from each drawing head 41 on the substrate 9 in the scanning direction.

In the drawing device 1, drawing on the substrate 9 is performed by a so-called single pass (one pass) method. Specifically, the stage 21 is moved relative to the plurality of drawing heads 41 in the Y direction by the stage movement mechanism 22, and the area irradiated with light from the plurality of drawing heads 41 is the substrate ( 9) is scanned only once in the Y direction (i.e. scanning direction) on the upper surface 91 of . In this way, drawing on the substrate 9 is completed. In addition, in the drawing device 1, drawing on the substrate 9 may be performed by a multi-pass method in which movement of the stage 21 in the Y direction and step movement in the X direction are repeated. When multi-pass drawing is performed in the drawing device 1, the Y direction is the main scanning direction and the X direction is the sub-scanning direction. Additionally, the first moving mechanism 23 of the stage moving mechanism 22 is a main scanning mechanism that moves the stage 21 in the main scanning direction, and the second moving mechanism 24 moves the stage 21 in the sub-scanning direction. It is a sub-injection device that moves.

FIG. 2 is a diagram showing the configuration of the computer 100. The computer 100 is a typical computer equipped with a processor 101, a memory 102, an input/output unit 103, and a bus 104. The bus 104 is a signal circuit that connects the processor 101, the memory 102, and the input/output unit 103. The memory 102 stores various types of information. The memory 102, for example, reads out and stores the program 109 previously stored in the storage medium 71. The storage medium 71 is, for example, USB memory or CD-ROM.

The processor 101 executes various processes (for example, numerical calculations and image processing) while using the memory 102 and the like according to the program 109 stored in the memory 102 and the like. The input/output unit 103 includes a keyboard 105 and mouse 106 that accept input from the operator, and a display 107 that displays output from the processor 101, etc.

In the drawing device 1, each function of the control unit 10 shown in FIG. 3 is realized by executing the program 109 by the computer 100. The control unit 10 is a part of the drawing device 1. FIG. 3 is a block diagram showing the function of the control unit 10. In Fig. 3, configurations other than the control unit 10 are also shown.

The control unit 10 shown in FIG. 3 controls the stage moving mechanism 22, the imaging unit 3, the drawing unit 4, etc. The control unit 10 includes a storage unit 111, an imaging control unit 112, a template creation unit 113, a template selection unit 114, a position detection unit 115, and a data creation unit 116. , and a drawing control unit 117. The storage unit 111 is mainly realized by the memory 102 and stores in advance various information regarding pattern drawing in the drawing device 1. Information stored in the storage unit 111 includes, for example, pattern CAD data (hereinafter also referred to as “second CAD data”), which is CAD data of the second pattern scheduled to be drawn on the substrate 9, and information described later. A template used for the alignment process of the substrate 9 is included.

The imaging control unit 112, template creation unit 113, template selection unit 114, position detection unit 115, data generation unit 116, and drawing control unit 117 are mainly realized by the processor 101. The imaging control unit 112 moves the stage 21 by controlling the stage moving mechanism 22, and images a part of the upper surface 91 of the substrate 9 by controlling the imaging unit 3, An image of a part of the pattern (hereinafter also referred to as a “captured image”) is acquired. The captured image is, for example, a gray scale image, and is used in the alignment process of the substrate 9, as will be described later. The captured image is sent from the imaging unit 3 to the storage unit 111 and stored in the storage unit 111.

The template creation unit 113 generates a plurality of templates to be used during the alignment process of the substrate 9 based on pattern CAD data (hereinafter also referred to as “first CAD data”), which is the CAD data of the first pattern. do. In the storage unit 111, two or more templates selected from the plurality of templates are stored as a template group used for pattern matching. The template selection unit 114 selects an application template, which is one template suitable for pattern matching for the captured image, from the template group. The position detection unit 115 determines the position of the substrate 9 on the stage 21 (i.e., the position of the substrate 9 with respect to the drawing unit 4) by performing pattern matching on the captured image using the application template. ) detects the relative position of ).

In the drawing device 1, the position of the substrate 9 is detected by the position detection unit 115, the template selection unit 114, the template generation unit 113, the storage unit 111, and the imaging unit 3. A position detection device 6 is configured. In Fig. 3, the components included in the position detection device 6 are surrounded by a two-dot chain line. The position detection device (6) is. It is a part of the drawing device 1 and may include structures other than the above-described structures. For example, the stage 21, the stage moving mechanism 22, the imaging control unit 112, etc. may be included in the position detection device 6. In addition, when the type of application template selected by the template selection unit 114, etc. is displayed on the display 107 shown in FIG. 2, the display 107, which is a display unit, may also be included in the position detection device 6.

The data generation unit 116 rasterizes the above-described second CAD data and generates drawing data that is raster data (hereinafter also referred to as “second drawing data”). The second drawing data is, for example, run length data. The drawing control unit 117 moves the drawing unit 4 and the stage based on the second drawing data generated by the data generation unit 116 and the position of the substrate 9 detected by the position detection unit 115. By controlling the mechanism 22, the drawing section 4 is made to execute drawing of the second pattern on the substrate 9 while adjusting the drawing position on the substrate 9.

Additionally, the control unit 10 may be realized by a programmable logic controller (PLC: Programmable Logic Controller), a circuit board, etc., or by a combination of these with one or more computers.

Figure 4 is a diagram showing an example of a template. The template 81 shown in FIG. 4 is generated from the first CAD data by the template creation unit 113. Specifically, the template creation unit 113 generates the template 81 by selecting a template area of a predetermined size from the first CAD data and rasterizing the template area. The template area is a relatively small, approximately rectangular area that is part of the first pattern indicated by the first CAD data. The first pattern includes a plurality of pattern elements, and the template area includes at least a portion of one or more pattern elements among the plurality of pattern elements. Additionally, the template area is an area smaller than the field of view of each imaging head 31 (see FIG. 1) of the imaging unit 3.

In the example shown in FIG. 4 , the template 81 includes a substantially straight portion that is part of one pattern element 93 included in the first pattern. The pattern element 93 illustrated in FIG. 4 extends substantially parallel to the vertical direction in the figure, and the width (i.e., line width) B1 in the left and right directions perpendicular to the longitudinal direction of the pattern element 93 is It is approximately constant along the entire longitudinal length. In FIG. 4 , a parallel diagonal line is provided to the pattern element 93, and the edge of the pattern element 93 (that is, the boundary between the pattern element 93 and the background area 96) is indicated by a thick line. The same applies to Figures 5 and 6. In the actual template area 81, at least a portion of one or more pattern elements having a more complex shape than the pattern element 93 illustrated in FIG. 4 is included.

In the first CAD data, each pattern element included in the first pattern is defined as the same shape as the shape specified in the design drawing or the like. Therefore, in the first CAD data, the line width of each pattern element is the line width as designed (that is, the line width specified in the design drawing, etc.). Also, in the template 81 generated from the first CAD data, the line width of the pattern element 93 included in the template 81 is the same as the line width specified in the design drawing or the like. In the following description, the template 81 is also called the “reference template 81.” Additionally, the first CAD data is also called “standard CAD data.”

FIGS. 5 and 6 are diagrams showing templates 82a and 82b in which the line width of the pattern element 93 included in the reference template 81 shown in FIG. 4 is changed. In the following description, the templates 82a and 82b are also called “offset template 82a” and “offset template 82b,” respectively. In the offset template 82a illustrated in FIG. 5 , the line width of the pattern element 93a is smaller than the line width of the pattern element 93 of the reference template 81. In addition, in the offset template 82b illustrated in FIG. 6, the line width of the pattern element 93b is larger than the line width of the pattern element 93 of the reference template 81. The difference in line width between the pattern element 93 and the pattern element 93a may be the same as or different from the difference in line width between the pattern element 93 and the pattern element 93b.

The offset templates 82a and 82b are generated by the template creation unit 113 shown in FIG. 3. Specifically, the template creation unit 113 generates offset CAD data in which the line width of the first pattern of the first CAD data (i.e., reference CAD data) is reduced according to a predetermined rule. In the offset CAD data, for example, the line width of each pattern element included in the first pattern is smaller than the reference CAD data by a predetermined value (for example, 5 μm). And, in the offset CAD data, an area corresponding to the above-described template area (i.e., an area of the same size and located at the same position as the above-described template area, hereinafter also simply referred to as “template area”) is, By being selected and rasterized by the template creation unit 113, the offset template 82a is created.

Additionally, the template creation unit 113 generates offset CAD data in which the line width of the first pattern of the first CAD data (i.e., reference CAD data) is increased according to a predetermined rule. In the offset CAD data, for example, the line width of each pattern element included in the first pattern is larger than the reference CAD data by a predetermined value (for example, 5 μm). Then, in the offset CAD data, an area corresponding to the template area described above is selected by the template creation unit 113 and rasterized, thereby generating an offset template 82b.

In the template creation unit 113, three or more offset templates may be generated. For example, in addition to the offset templates 82a and 82b described above, an offset template with a smaller line width of pattern elements than the offset template 82a and an offset template with a larger line width of pattern elements than the offset template 82b are provided in the template creation unit. It may be generated in (113).

Additionally, the plurality of offset templates generated by the template creation unit 113 may only have pattern elements whose line widths are smaller than those of the reference template 81, such as the offset template 82a. Alternatively, the plurality of offset templates generated in the template creation unit 113 may only have a line width of pattern elements larger than that of the reference template 81, such as the offset template 82b. In addition, each offset template generated in the template creation unit 113 has only the line width changed from the reference template 81, and does not include any transformation other than changing the line width by rotating or deforming the reference template 81. .

The reference template 81 generated in the template creation unit 113 and a plurality of offset templates (offset templates 82a and 82b in this embodiment) are stored in the storage unit 111. Additionally, in the storage unit 111, a set of templates including two or more templates among the reference template 81 and a plurality of offset templates is selected and stored as a template group used for pattern matching.

The template group may include all templates generated in the template generation unit 113 (i.e., the reference template 81 and a plurality of offset templates), or may include only a portion of all templates generated in the template generation unit 113. It may be included. The template group may or may not include the standard template 81. That is, the template group may include the reference template 81 and one or more offset templates among a plurality of offset templates. Alternatively, the template group may not include the reference template 81 but may include two or more offset templates among a plurality of offset templates.

Next, an example of the flow of pattern drawing on the substrate 9 by the drawing device 1 will be described with reference to FIG. 7 . When drawing on the substrate 9, first, in the template generating unit 113, a reference template 81 and an offset template 82a, 82b (see FIGS. 4-6) corresponding to the above-described template area are created. is generated and stored in the storage unit 111 (step S11).

In the storage unit 111, two or more templates are selected from the reference template 81 and the offset templates 82a and 82b, and the template group including the two or more templates is stored and prepared (step S12). . In this embodiment, the template group is composed of three templates: the reference template 81 and the offset templates 82a and 82b. In other words, the template group includes all templates created in the template creation unit 113. In steps S11 to S12, a reference template 81 and an offset template 82a, 82b are generated for each of a plurality of template areas with different positions on the first pattern, and each corresponding to the plurality of template areas is generated. A plurality of template groups are stored in the storage unit 111.

Subsequently, the substrate 9 is carried into the drawing device 1 shown in FIG. 1 and held by the stage 21. The stage 21 is located at a loading/unloading position on the (-Y) side from the imaging unit 3 and the drawing unit 4. On the upper surface 91 of the substrate 9 held on the stage 21, the first pattern described above is formed in advance.

Next, the substrate 9 is moved in the (+Y) direction together with the stage 21 by the stage moving mechanism 22, and is positioned below the imaging unit 3. Then, the imaging unit 3 and the stage moving mechanism 22 are controlled by the imaging control unit 112 (see FIG. 3), so that a plurality of imaging areas each corresponding to a plurality of template areas are formed on the substrate 9. An image is captured, and a plurality of captured images each including a part of the first pattern are acquired (step S13). The above-mentioned imaging area is an area where pattern matching by the position detection unit 115 is performed, as will be described later, and is hereinafter also referred to as a “matching area.”

Each of the plurality of imaging areas is a substantially rectangular area with the corresponding template area as the center, with the substrate 9 accurately held at the designed position on the stage 21. The shapes and sizes of the plurality of imaging areas are the same. The imaging area has a pair of sides parallel to the X and Y directions, and is larger than the corresponding template area in both the X and Y directions. Therefore, even if the position of the substrate 9 on the stage 21 is slightly deviated from the designed position, the pattern element 93 included in the template area is included in the captured image. The captured image acquired in step S13 is stored in the storage unit 111. In addition, step S13 may be performed before steps S11 to S12, or may be performed in parallel with steps S11 to S12.

On the upper surface 91 of the substrate 9 on which imaging is performed in step S13, another pattern is previously formed below the first pattern (i.e., the layer on the (-Z) side of the layer on which the first pattern is formed). There are cases where it is done. For example, if another pattern located below the first pattern (hereinafter also referred to as a “lower layer pattern”) is included in the above-described captured image, there is a possibility that the lower layer pattern will be mistaken for the first pattern in pattern matching described later. There is. Therefore, in the drawing device 1, the upper and lower sides of each imaging head 31 are adjusted so that the range of the depth of focus of each imaging head 31 of the imaging unit 3 includes the first pattern and does not include the lower layer pattern. The position of the direction is adjusted. Thereby, it is possible to suppress or prevent the lower layer pattern from being included in the captured image acquired in step S13.

When step S13 is completed, the template selection unit 114 (see FIG. 3) performs pattern matching on each captured image using the above-described template group corresponding to each captured image, and selects the applied template ( Step S14). Specifically, first, one captured image is selected, and the template group corresponding to the one captured image is read from the storage unit 111. Subsequently, pattern matching is performed on the single captured image for each of the plurality of templates included in the template group, and a matching score when each template is used is obtained. Then, based on the matching score corresponding to each template, one template suitable for pattern matching is selected from the template group, and this one template is set as an “applied template” applied to detecting the position of the substrate 9. In step S14, for each of the plurality of imaging areas, an application template is selected from the corresponding template group as above.

The pattern matching in step S14 may be performed by various known pattern matching methods (for example, geometric shape pattern matching, normalized correlation search, etc.). In this embodiment, pattern matching in step S14 is performed using the edges of pattern elements included in each template and captured image. In addition, when selecting an application template, the matching scores of each template included in the template group are compared, and the one with the highest matching score (that is, the one with a higher degree of matching with the captured image) becomes the application template.

Additionally, in step S14, the template with the highest matching score does not necessarily have to be the application template, and another template may be the application template. For example, if the matching score when using the offset template 82a is the maximum and the matching score when using the reference template 81 is slightly smaller than the matching score of the offset template 82a, the reference template ( 81) This may be selected as the application template. Alternatively, any one template may be selected from a plurality of templates whose matching score is greater than a predetermined threshold.

When step S14 is completed, the position of the substrate 9 is detected by the position detection unit 115 (see FIG. 3) based on the result of pattern matching using the applied template for each captured image (step S15). Specifically, based on the position of the pattern element identical to the template in each captured image and the relative position of the substrate 9 and the imaging unit 3 when each captured image is acquired, etc., on the stage 21 The position of the substrate 9 is detected. In step S15, as a result of pattern matching using the applied template, for example, among the pattern matching performed by each template performed in step S14, the result of pattern matching using the template that finally became the applied template is used. Alternatively, pattern matching using the application template corresponding to each captured image may be performed again for each captured image, and the result of the pattern matching may be used.

When pattern matching is performed in step S15, the pattern matching may be performed by various known pattern matching methods (for example, geometric shape pattern matching, normalized correlation search, etc.). For example, the pattern matching in step S15 is performed using the edges of pattern elements included in each template and the captured image, similarly to step S14. In addition, the pattern matching for the plurality of captured images in step S15 may be performed in parallel with the selection of the application template for the plurality of captured images in step S14. For example, selection of the application template corresponding to one captured image may be performed in parallel with pattern matching for another captured image for which the application template has been selected.

The position of the substrate 9 detected by the position detection unit 115 in step S15 refers to the coordinates in the X and Y directions of the substrate 9 on the stage 21 and the direction of the substrate 9. , and includes information indicating deformation due to distortion of the substrate 9, etc. In addition, the information indicating the deformation of the substrate 9 is information such as the shape of the deformed substrate 9. As described above, in the drawing device 1, an application template suitable for pattern matching is selected from the template group, and alignment processing of the substrate 9 is performed using the application template. Therefore, the position of the substrate 9 on the stage 21 can be detected with high precision.

When step S15 is completed, the second CAD data is read from the storage unit 111 by the data generation unit 116 (see FIG. 3), the second CAD data is rasterized, and the second drawing data is generated. (Step S16). Additionally, step S16 may be performed in parallel with step S15 or may be performed before step S15. When step S16 is performed before step S15, for example, step S16 may be performed in parallel with any of steps S11 to S14, or may be performed between any two steps of steps S11 to S14, and step S11 It may be carried out earlier.

When the second drawing data is generated, based on the second drawing data and the position of the substrate 9 detected in step S15, the drawing unit 4 and the stage moving mechanism 22 are operated by the drawing control unit 117 (see Fig. 3). ) is controlled by . Accordingly, the above-mentioned modulated light is irradiated toward the substrate 9 that is relatively moved in the Y direction with respect to the drawing head 41 of the drawing unit 4, and is projected onto the upper surface 91 of the substrate 9. 2 Patterns are drawn (step S17). In step S17, based on the position of the substrate 9 detected in step S15, the modulation interval and modulation timing of the light beam irradiated from the drawing unit 4 to the substrate 9 are determined, and the modulation interval and modulation timing on the substrate 9 are determined. The scanning position of the light beam, etc. is automatically and mechanically corrected in the drawing unit 4 and the stage moving mechanism 22 using a known correction method. Thereby, the second pattern can be drawn on the first pattern with good positional accuracy.

The substrate 9 on which the drawing of the second pattern has been completed is unloaded from the drawing device 1. Then, the new substrate 9 on which the first pattern is formed in advance is brought into the drawing device 1, and the steps S11 to S17 described above are performed, thereby drawing the second pattern on the first pattern.

In the drawing device 1, after the second pattern is drawn on a plurality of substrates 9 of a predetermined number (e.g., 1 lot), selected images are respectively selected for the plurality of captured images of each substrate 9. The type of template to be applied is displayed in display 107. Specifically, for each of a plurality of imaging areas (i.e., a plurality of matching areas) set on the substrate 9, the type of application template selected in step S14 when drawing the second pattern for each substrate 9. (For example, a name or symbol representing one template selected from the reference template 81 and the offset templates 82a and 82b) is listed and displayed on the display 107 for each imaging area and for each substrate 9. The operator can utilize the above indications on the display 107 for various purposes.

As described above, the position detection device 6 that detects the position of the substrate 9 includes an imaging unit 3, a storage unit 111, a template selection unit 114, and a position detection unit 115. is provided. The imaging unit 3 images a part of the pattern (the first pattern in the above example) previously formed on the upper surface 91 of the substrate 9. The storage unit 111 stores a template group. The template group includes a reference template 81, which is a template generated from reference CAD data (in the above example, first CAD data), which is CAD data of the pattern, and pattern elements 93 included in the reference template 81. Among the plurality of offset templates 82a and 82b, which are templates with respective line widths changed, two or more templates are included. The template selection unit 114 performs pattern matching on the captured image acquired by the imaging unit 3 using each template included in the template group, and selects an applied template from the template group based on the matching score. . The position detection unit 115 detects the position of the substrate 9 based on the result of pattern matching using the template applied to the captured image.

In the position detection device 6, as described above, an application template suitable for pattern matching is selected from a plurality of templates having different line widths of patterns, thereby determining the line width of the pattern provided on the substrate 9 from the design value. Even when there is a difference or a difference from the design value of the line width of the pattern acquired from the captured image, the position of the substrate 9 can be detected with high precision.

As described above, pattern matching by the template selection unit 114 is preferably performed using the edges of pattern elements included in the applied template and the captured image, respectively. Thereby, pattern matching in step S14 can be easily performed, and the position of the substrate 9 can be easily detected. Additionally, in pattern matching using the edges of pattern elements, if the line width of the template is different from the actual line width on the substrate, the matching score decreases relatively significantly and the position detection accuracy of the substrate 9 also decreases. In contrast, in the position detection device 6 described above, pattern matching is performed using an application template with a line width suitable for pattern matching, so even in pattern matching using the edges of pattern elements, the position of the substrate 9 is determined. It can be detected with high precision. The same applies to the case where pattern matching is performed in step S15.

As described above, the position detection device 6 further includes a template creation unit 113 that generates the reference template 81 by selecting a template area of a predetermined size from the reference CAD data and rasterizing it. desirable. In this way, since the reference template 81 can also be generated in the position detection device 6, work related to detecting the position of the substrate 9 can be performed by integrating it with the position detection device 6. As a result, the work related to detecting the position of the substrate 9 can be simplified.

As described above, the template creation unit 113 selects and rasterizes the template areas from a plurality of offset CAD data in which the line widths of the patterns of the reference CAD data are each changed, thereby creating a plurality of offset templates 82a and 82b. ) is desirable to generate. In this way, by also generating the offset templates 82a and 82b in the position detection device 6, the work related to detecting the position of the substrate 9 can be further simplified.

As described above, a lower layer pattern located below the pattern (the first pattern in the above example) may be formed in advance on the upper surface 91 of the substrate 9. In this case, it is preferable that the depth of focus of the imaging unit 3 includes the pattern and does not include the lower layer pattern. As a result, it is possible to suppress erroneous detection of the edge of the lower layer pattern as the edge of the first pattern during pattern matching in step S14 and step S15. As a result, the accuracy of detecting the position of the substrate 9 can be improved. In particular, when a plurality of pattern elements arranged in a stripe shape or border shape are included in the pattern and the lower layer pattern and overlap in the vertical direction, by excluding the lower layer pattern from the range of the depth of focus as described above, the substrate (9) The position detection accuracy can be preferably improved.

As described above, the position detection device 6 includes a display unit (in the above example, display 107) that displays the type of application template selected by the template selection unit 114 for each of the predetermined number of substrates 9. )) is preferably additionally provided. Thereby, the operator who sees the display on the display unit can easily grasp the tendency of the application template selected in each of the plurality of imaging areas (i.e., matching areas) on the substrate 9. Additionally, the operator can easily determine the trend of application templates selected for each processing day or processing time. The operator can use the identified above-described trends for various purposes (for example, correcting bias in the etching process for the substrate 9, etc.). In addition, the display unit is not limited to the display 107, and may have various other configurations (for example, a printer that prints and displays the type of application template on printing paper).

As described above, the drawing device 1 for drawing a pattern by irradiating light to the substrate 9 includes the position detection device 6, the stage 21, and the drawing head 41, It is provided with a scanning mechanism (in the above example, the stage moving mechanism 22) and a drawing control unit 117. The stage 21 holds the substrate 9. The drawing head 41 irradiates the upper surface 91 of the substrate 9 with modulated light. The scanning mechanism moves the stage 21 relative to the drawing head 41 in the scanning direction parallel to the upper surface 91 of the substrate 9 (Y direction in the above example). The drawing control unit 117 controls the drawing head 41 and the scanning mechanism based on the position of the substrate 9 detected by the position detection device 6, thereby moving the drawing head 41 relative to the scanning direction. Drawing on the substrate 9 is executed. As described above, the position detection device 6 can detect the position of the substrate 9 with high precision. For this reason, in the drawing device 1, the pattern (in the above example, the second pattern) on the substrate 9 can be drawn with high positional accuracy.

The above-described position detection method for detecting the position of the substrate 9 includes a step (step) of imaging a part of a pattern (in the above example, the first pattern) previously formed on the upper surface 91 of the substrate 9. S13) and the reference template 81, which is a template generated from reference CAD data (in the above example, first CAD data), which is CAD data of the pattern, and the line width of the pattern element 93 included in the reference template 81. A process of preparing a template group containing two or more templates among the plurality of offset templates 82a and 82b, which are respectively changed templates (steps S11 to S12), and assigning a template group to the template group for the captured image in step S13. A process of performing pattern matching using each included template and selecting a template to be applied from the template group based on the matching score (step S14), and applying a template to the substrate based on the result of pattern matching using the applied template for the captured image. (9) A process for detecting the position (step S15) is provided. Thereby, as described above, the position of the substrate 9 can be detected with high precision.

As described above, the program 109 is executed by the computer 100 to image a part of the pattern (in the above example, the first pattern) previously formed on the upper surface 91 of the substrate 9. A process (step S13), a reference template 81 which is a template generated from reference CAD data (in the above example, first CAD data) which is CAD data of the pattern, and a pattern element 93 included in the reference template 81. A process of preparing a template group containing two or more templates (steps S11 to S12) among a plurality of offset templates 82a and 82b, which are templates with respective line widths changed, and A process of performing pattern matching using each template included in the template group and selecting a template to be applied from the template group based on the matching score (step S14); and the result of pattern matching using the applied template for the captured image. Based on this, a process (step S15) of detecting the position of the substrate 9 is performed. Thereby, as described above, the position of the substrate 9 can be detected with high precision.

As described above, on the substrate 9, a plurality of matching areas (i.e., imaging areas) where pattern matching is respectively performed by the position detection unit 115 are set. Then, in the template selection unit 114, pattern matching using each template of the corresponding template group is performed for each of the plurality of matching areas, and an applied template is selected from the template group based on the matching score of each template. do. However, selection of the application template by the template selection unit 114 may be performed by another method.

For example, the template used for pattern matching in one matching area among a plurality of matching areas is selected by the template selection unit 114 for two or more matching areas other than the one matching area among the plurality of matching areas. Based on two or more application templates each selected by , the template is selected from a group of templates corresponding to the one matching area. As a result, the time required to detect the position of the substrate 9 in which multiple matching areas are set can be shortened.

Specifically, for example, for the four matching areas located at each vertex of the square area on the substrate 9, the method described in step S14 described above (i.e., selecting the template with the highest matching score from the template group) Method), each applicable template is selected from the template group. In addition, when the four applied templates are the same type of template (e.g., the reference template 81), pattern matching using each template of the template group is not performed in other matching areas located inside the square area. Instead, a template identical to the application template selected from the four matching areas (e.g., the reference template 81) is selected as the application template.

Alternatively, the application template selected by the method described in step S14 for three of the four matching regions located at each vertex of the above-described square region is the offset template 82a, and the method is used for one matching region. Let us assume that the selected application template was the reference template (81). In this case, among the plurality of matching areas located inside the square area, pattern matching using each template of the template group is not performed in the matching areas that are geographically close to the three matching areas, and the offset template 82a is used. This is selected as the application template. In addition, among the plurality of matching areas located inside the square area, in a matching area that is geographically close to the one matching area, pattern matching using each template of the template group is not performed, and the reference template 81 is used. It is selected as the application template.

In addition, the specific method of selecting an application template based on the application templates of two or more other matching areas without performing pattern matching using each template of the template group for one matching area is limited to the example described above. It does not work, and may be changed in various ways.

The position detection device 6 described above may further include a template group change unit 118, as shown in FIG. 8 . The template group change unit 118 generates a new offset template based on the result of pattern matching using each template included in the template group by the template selection unit 114 and adds it to the template group. As a result, in the detection of the position of the substrate 9 performed after addition of the offset template, an application template more suitable for pattern matching to the captured image can be selected. As a result, the position detection accuracy of the substrate 9 can be further improved.

Specifically, for example, for one matching area, the matching score of each template in the template group is obtained by the template selection unit 114. Subsequently, the matching score of each template is the difference between the line width of the pattern element in each template and the line width of the pattern element 93 in the standard template 81 (hereinafter also referred to as the “standard line width difference”). It is graphed using the horizontal axis. Next, in the graph (i.e., scatter plot), the matching scores of a plurality of templates included in the template group are polynomially approximated, and the reference line width difference at the peak of the approximation line (i.e., the maximum value of the matching score) is obtained. Then, a new offset template whose line width is different from the reference template 81 by the obtained reference line width difference is generated by the template group change unit 118 and added to the template group. Generation of the new offset template is performed, for example, in the same manner as the offset templates 82a and 82b described above.

Additionally, when the template group change unit 118 adds a new offset template to the template group, for example, among a plurality of templates included in the template group, the template with the largest line width difference with the new offset template is selected from the template group. It may be excluded. As a result, it is possible to suppress the increase in processing amount when selecting the application template in step S14.

Various changes are possible in the position detection device 6, position detection method, program 109, and drawing device 1 described above.

For example, the generation of the offset templates 82a and 82b by the template creation unit 113 does not necessarily need to be achieved by rasterizing the template area selected from the offset CAD data described above, and may be changed in various ways. For example, in the reference template 81 that is bitmap data, the offset templates 82a and 82b may be generated by changing the line width of the pattern element 93.

In addition, the reference template 81 and the offset templates 82a and 82b do not necessarily need to be generated in the position detection device 6, but are generated in another device and sent to the position detection device 6, and are stored in the storage unit 111. ) may be stored in . In this case, the template creation unit 113 may be omitted from the position detection device 6.

In the position detection device 6, the type of application template selected for each of the predetermined number (e.g., 1 lot) of substrates 9 does not necessarily need to be displayed. In this case, the above-described display part may be omitted from the position detection unit 115.

In the position detection device 6, the application template selected as described above for one substrate 9 is applied to another substrate 9 related to the one substrate 9 (e.g., the one substrate ( It may be applied to another substrate (9)) of the same lot as 9). In this case, in the other substrate 9, the calculation of the matching score of each template and the selection of the application template in step S14 are omitted, so the time required for the alignment process of the other substrate 9 can be shortened. You can.

The range of the depth of focus of the imaging unit 3 is not limited to the above example and may be changed in various ways.

The position detection device 6 does not necessarily need to be a part of the drawing device 1, and may be used as a device independent from the drawing device 1.

The configurations in the above embodiment and each modification may be appropriately combined as long as they do not conflict with each other.

Although the invention has been described and explained in detail, the description is illustrative and not limiting. Accordingly, it can be said that many modifications and aspects are possible as long as they do not deviate from the scope of the present invention.

1: Drawing device
3: Imaging unit
6: Position detection device
9: substrate
21: Stage
22: Stage moving mechanism
41: drawing head
81: Reference template
82a, 82b: offset template
91: top surface (of substrate)
93, 93a, 93b: pattern elements
107: display
109: program
111: memory unit
113: Template creation unit
114: Template selection section
115: Position detection unit
117: Drawing control unit
118: Template group change section
S11 ~ S17: Step

Claims (11)

A position detection device that detects the position of a substrate, comprising:
an imaging unit that captures an image of a portion of a pattern previously formed on the upper surface of the substrate;
A template group including two or more templates is stored among a reference template that is a template generated from reference CAD data, which is the CAD data of the pattern, and a plurality of offset templates that are templates in which the line widths of pattern elements included in the reference template are respectively changed. A memory unit that says,
a template selection unit that performs pattern matching using each template included in the template group on the captured image acquired by the imaging unit and selects an application template from the template group based on a matching score;
A position detection device comprising a position detection unit that detects the position of the substrate based on a result of pattern matching using the application template for the captured image. According to claim 1,
A position detection device wherein pattern matching by the template selection unit is performed using edges of pattern elements included in each of the application template and the captured image. The method of claim 1 or 2,
A position detection device further comprising a template creation unit that generates the reference template by selecting a template area of a predetermined size from the reference CAD data and rasterizing it. According to claim 3,
The template generator generates the plurality of offset templates by selecting the template areas from the plurality of offset CAD data in which the line widths of the patterns of the reference CAD data are respectively changed and rasterizing them. The method of claim 1 or 2,
A position detection device further comprising a display unit that displays the type of the application template selected by the template selection unit for each of a predetermined number of substrates. The method of claim 1 or 2,
A position detection device further comprising a template group change unit that generates a new offset template based on a result of pattern matching using each template included in the template group by the template selection unit and adds it to the template group. The method of claim 1 or 2,
On the substrate, a plurality of matching areas are set where pattern matching by the position detection unit is performed, respectively,
The template used for pattern matching in one matching area among the plurality of matching areas is two templates each selected by the template selection unit for two or more matching areas other than the one matching area among the plurality of matching areas. Based on the more than one applied template, the position detection device is selected from the template group corresponding to the one matching area. The method of claim 1 or 2,
A lower layer pattern located below the pattern is previously formed on the upper surface of the substrate,
A position detection device, wherein the pattern is included in the range of the depth of focus of the imaging unit, and the lower layer pattern is not included. A drawing device that draws patterns by irradiating light to a substrate, comprising:
The position detection device according to claim 1 or 2,
a stage holding the substrate,
a drawing head that irradiates modulated light onto the upper surface of the substrate;
a scanning mechanism that moves the stage relative to the drawing head in a scanning direction parallel to the upper surface of the substrate;
A drawing control unit that controls the drawing head and the scanning mechanism based on the position of the substrate detected by the position detection device to execute drawing on the substrate moving relative to the drawing head in the scanning direction. A drawing device that does. As a position detection method for detecting the position of a substrate,
a) a process of imaging a portion of a pattern previously formed on the upper surface of a substrate,
b) A template group including two or more templates among a reference template that is a template generated from reference CAD data, which is the CAD data of the pattern, and a plurality of offset templates that are templates in which the line widths of pattern elements included in the reference template are changed, respectively. The process of preparing,
c) performing pattern matching using each template included in the template group for the captured image acquired in step a) above, and selecting an application template from the template group based on a matching score;
d) A position detection method comprising a step of detecting the position of the substrate based on a result of pattern matching using the application template for the captured image. A program recorded on a recording medium that detects the position of a substrate, comprising:
As the above program is executed by the computer,
a) a process of imaging a portion of a pattern previously formed on the upper surface of a substrate,
b) A template group including two or more templates among a reference template that is a template generated from reference CAD data, which is the CAD data of the pattern, and a plurality of offset templates that are templates in which the line widths of pattern elements included in the reference template are changed, respectively. The process of preparing,
c) performing pattern matching using each template included in the template group for the captured image acquired in step a) above, and selecting an application template from the template group based on a matching score;
d) A program recorded on a recording medium, wherein a process of detecting the position of the substrate is performed based on a result of pattern matching using the application template for the captured image.