JP2005338555A - Exposure apparatus, exposure method and exposure processing program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an exposure apparatus for improving the yield. <P>SOLUTION: The exposure apparatus which carries out alignment and exposure in the entire region of a substrate or in each region preliminarily segmented is equipped with: a means 36 to judge whether the substrate can be exposed or not based on a substrate mark and a mask mark formed on the substrate and a mask 10 having a pattern to be formed in the substrate, respectively, both marks photographed by a photographing means 20; a memory means 32 to memorize the information about the substrate judged as inappropriate for exposure and the information about a region not exposed which is the region judged as inappropriate for exposure, as error information; and an exposure controlling means 31 which controls to carry out alignment and exposure in the unexposed region based on the error information memorized in the memory means 32 when a substrate having an unexposed region is again introduced after completing the alignment and exposure on a series of substrates in a predetermined number. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an exposure apparatus, an exposure method, and an exposure processing program that perform alignment processing and exposure processing for each entire region of a substrate or for each region that is divided in advance for exposure.

  A technique related to an exposure apparatus configured to attach a printed wiring board (hereinafter simply referred to as a board) to a mask and project and print a pattern drawn on the mask onto the board with light from a light irradiation mechanism is known. (For example, refer to Patent Document 1).

  The arrangement of this exposure apparatus is well known to those skilled in the art. Briefly, the exposure apparatus includes a table for placing a substrate, a mask for applying a predetermined pattern to the substrate, and light irradiation. The mechanism is installed. And in order to perform the alignment process which aligns a mask with the predetermined position of a board | substrate, a table can be moved to a plane direction (XY (theta) direction), and also can be moved also to a perpendicular direction (Z direction). Therefore, the substrate can be moved in the Z direction so as to be in close contact with the mask. The substrate is transported from the previous line by the carry-in device, placed on the table, subjected to the alignment process, exposed (after pattern printing), and sent to the next process by the carry-out device.

The substrate is preliminarily divided into a plurality of (for example, four) areas for exposure, and a circuit pattern drawn on a mask is sequentially printed on each area. A mask is located on the table, and a CCD camera is provided above the mask. In order to detect the position of the mask and the substrate on the table, alignment marks (mask mark and substrate mark) are provided at appropriate positions of the mask and the substrate, respectively. The table is moved in the XYθ direction so that the mask mark photographed by the CCD camera and the substrate mark are matched, thereby performing alignment (alignment).
JP 2000-250227 A (paragraphs 0005 to 0017, FIG. 1)

  However, the alignment process recognizes the position of the substrate mark, calculates the center position of the entire substrate mark, and moves the substrate based on the amount of deviation from the center position. Thus, when the position of the substrate mark cannot be recognized, the alignment process cannot be performed, and therefore the exposure process is not executed. Even when the alignment process is performed, the exposure process is not executed when the substrate size changes due to a high temperature and the deviation between the mask mark and the substrate mark exceeds the allowable range. Thus, the board | substrate with which the area | region (exposure unprocessed area | region) where the exposure process is unprocessed generate | occur | produced conventionally was discarded as an unqualified product. Therefore, the conventional exposure apparatus has a problem that the yield is low.

  Therefore, an object of the present invention is to provide an exposure apparatus capable of solving the above-described problems and improving the yield.

  The exposure apparatus according to the present invention is configured as follows in order to solve the above problems. That is, in the exposure apparatus that performs the alignment process and the exposure process for each of the entire area of the substrate or each of the areas previously divided for exposure, the substrate and the mask having a pattern formed on the substrate are respectively formed. Discrimination means for discriminating whether or not the substrate can be exposed based on the two marks obtained by photographing the substrate mark and the mask mark by the photographing means, information relating to the substrate determined to be unexposure by the discrimination means, and the substrate Storage means for storing, as error information, information relating to an unprocessed area that is determined to be non-exposure, and a substrate in which the unexposed area is subjected to the alignment process and the exposure process for a series of substrate numbers. Based on the error information stored in the storage means when the image is re-input after being completed, the exposure unprocessed An exposure processing control means for controlling so as to execute the matching process and the exposure process to pass, and a structure comprising a.

  With this configuration, the exposure apparatus stores, as error information, information related to the substrate that has been determined to be non-exposure and information related to an unprocessed area that has been determined to be unexposure on the substrate as error information. . Then, after the alignment process and the exposure process for a series of the number of substrates are completed, when the substrate in which the error information is stored is reloaded, the substrate is exposed based on the error information stored in the storage unit. Only the unprocessed area is subjected to the alignment process and the exposure process.

  Further, the exposure apparatus displays information indicating which part on the substrate is the unexposed region based on the pre-divided region of the substrate stored in the storage unit and the error information. The display portion is provided.

  With such a configuration, the exposure apparatus stores, as error information, information on which area is an unprocessed area for a defective substrate that is determined to be unexposure, and is stored in advance. Since the divided areas of the substrate are also stored in the storage means, the display unit can distinguish and display the unexposed areas and the exposed areas. As a result, even when the substrate is difficult to determine whether it is exposed or not in appearance when the defective substrate is re-inserted, the display unit can easily determine which region is unprocessed. .

  Further, as an exposure method, an exposure method in which alignment processing and exposure processing are performed for the entire region of the substrate or for each region that has been divided in advance for exposure is performed as follows. That is, the determination for determining whether or not the substrate can be exposed based on the substrate mark formed on each of the substrate and the mask having the pattern formed on the substrate and the both marks obtained by photographing the mask mark by the photographing means. A step of storing, as error information, information relating to a substrate that has been determined to be non-exposure in this determination step, and information relating to an unprocessed region that has been determined to be non-exposure on the substrate; When a substrate in which an area exists is re-inserted after completing the alignment process and the exposure process for a series of substrate numbers, the alignment process and the exposure process are performed on the unexposed area based on the error information. An exposure processing control step for controlling the exposure processing to be performed.

  In this way, the exposure method includes a step of storing, as error information, information relating to the substrate that has been determined to be unexposure and information relating to the unexposed area of this substrate. After the processing and the exposure processing are completed, when the substrate on which the error information is stored is reloaded, the alignment processing and the exposure processing are performed on the unexposed region based on the error information.

  Further, the exposure processing program causes a computer to function as the following means in order to execute alignment processing and exposure processing for the entire region of the substrate or for each region previously divided for exposure. To do.

  The means for causing the computer to function is that the substrate can be exposed based on the substrate mark formed on each of the substrate and a mask having a pattern formed on the substrate and the both marks obtained by photographing the mask mark by the photographing means. Error information that generates, as error information, information relating to a substrate that has been determined to be non-exposure by the determining means, and information relating to an unexposed area that is an area that has been determined to be non-exposure on the substrate Based on the error information generated by the error information generating means when the substrate in which the unexposed area is present is re-entered after completing the alignment process and the exposure process for a series of substrate numbers. An exposure processing control for controlling the alignment processing and the exposure processing to be performed on the unexposed region. Means, it is.

  In this way, the exposure processing program generates, as error information, information on the substrate that has been determined to be non-exposure by the error information generation unit and information on the unexposed area of this substrate, so that a series of the number of substrates When the substrate on which the error information is generated after the alignment process and the exposure process are turned on again, the alignment process and the exposure process are performed on the unexposed area based on the error information. .

  According to the present invention, since alignment processing and exposure processing can be performed again only on unexposed areas of the substrate once subjected to alignment processing and exposure processing, defective substrates are reduced and yield is improved. It becomes possible.

Next, embodiments of the present invention will be described in detail with reference to the drawings as appropriate. FIG. 1 is an external view of an exposure apparatus according to this embodiment.
The exposure apparatus 1 performs an exposure process on both sides of a substrate (work) carried in, and discharges the substrate on which the exposure process has been performed. As shown in FIG. 1, the surface exposure unit 2 (2A) A back exposure unit 2 (2B), a workpiece reversing unit 3, a stocker 4, a control device 5, an exposure state display monitor 6 (6A, 6B), and an alignment state display monitor 7 (7A, 7B). I have.

The surface exposure unit 2 (2A) performs an exposure process on one surface (front surface) of the substrate, and includes a table 9 (9A) on which the substrate is placed and a mask 10 (10A) having a pattern formed on the substrate. ) Etc.
The back surface exposure unit 2 (2B) performs an exposure process on the other surface (back surface) of the substrate. A table 9 (9B) on which the substrate is placed and a mask 10 (10B) having a pattern formed on the substrate. ) Etc.
The work reversing unit 3 reverses the substrate subjected to the exposure processing in the front surface exposure unit 2A and sends it to the back surface exposure unit 2B.

The stocker 4 stores substrates for which exposure processing has not been executed normally.
The control device 5 controls the front surface exposure unit 2A, the back surface exposure unit 2B, and the stocker 4.
The exposure state display monitor 6 (6A, 6B) displays information indicating which part on the substrate is an unexposed area, and is disposed in the front surface exposure unit 2A and the back surface exposure unit 2B. .
The alignment state display monitor 7 (7A, 7B) displays an image of alignment marks (mask mark and substrate mark) at the alignment position between the substrate on the table 9 (9A, 9B) and the mask 10 (10A, 10B). This is provided in the front surface exposure unit 2A and the back surface exposure unit 2B. A substrate ID (identification number) is assigned near the substrate mark.

  Next, with reference to FIG. 2, the structure of the surface exposure part 2A and the back surface exposure part 2B is demonstrated. FIG. 2 is a block diagram showing a configuration of the front surface exposure unit 2A (back surface exposure unit 2B). Since the front exposure unit 2A and the back exposure unit 2B have the same configuration, only the configuration of the front exposure unit 2A will be described below. As shown in FIG. 2, the surface exposure unit 2A includes an imaging unit 20, a CCD drive unit 21, an exposure unit 22, a table drive unit 23, a vacuum pump 24, a vacuum pump drive unit 25, and a display screen. Output means 26, which are controlled by the control device 5.

The photographing means 20 comprises a CCD camera or the like, and outputs an image photographed by the CCD camera to the control device 5 as multi-value data. Four CCD cameras are arranged corresponding to four corners of a predetermined area of the substrate.
The CCD driving means 21 drives the photographing means 20, and the CCD camera constituting the photographing means 20 is moved up, down, left and right, and front and rear via a moving rail above the table 9 on which the substrate is placed. Move.

  The exposure unit 22 performs an exposure process on the substrate placed on the table 9. The exposure unit 22 includes a light transmission plate and a light irradiation mechanism (not shown). The translucent plate installed at the exposure position is composed of an acrylic plate that transmits ultraviolet rays of a predetermined wavelength, or a quartz glass plate, a synthetic quartz glass plate, etc., and a frame is provided on the periphery of the translucent plate A mask 10 is mounted on the surface of the translucent plate on the table 9 side. The light irradiation mechanism includes a discharge lamp such as a short arc lamp that irradiates light including ultraviolet rays of a predetermined wavelength, an elliptical reflecting mirror arranged so as to cover the rear of the discharge lamp, and the discharge lamp and the elliptical reflecting mirror. A fly-eye lens that adjusts the energy of the irradiation light to be uniform with respect to the irradiation surface, and a plurality of reflecting mirrors that reflect the irradiation light from the fly-eye lens to the exposure position as parallel light . A shielding plate for shielding the light from the light irradiation mechanism so as not to reach a predetermined region of the substrate is provided so as to be movable above the translucent plate.

  The table driving means 23 drives the table 9 based on a control signal from the control device 5 and moves the substrate on the table 9 to an alignment position with the mask 10. The table driving means 23 is provided on the table 9 and moves in the X direction for moving the mounting plate (the upper part of the table 9) on which the substrate is mounted in the X direction which is one horizontal direction. And a Y-direction moving unit for supporting the X-direction moving unit and moving the mounting plate in a Y direction that is a horizontal direction orthogonal to the moving direction of the X-direction moving unit, and the Y direction A θ direction moving unit for supporting the moving unit and moving the mounting plate in the θ direction, which is the direction around the vertical line, is provided. In order to bring the substrate into contact with the mask 10, a Z-direction moving part for moving in the Z direction, which is the vertical vertical direction, is provided so as to support the θ-direction moving part.

The vacuum pump 24 is used to bring the substrate and the mask 10 into vacuum contact or to vacuum-adsorb the substrate to the mounting plate. That is, although not shown, when placing the substrate on the mounting plate at the loading / unloading position, and a main vacuum pump for detachably vacuum-sucking the mask 10 of the translucent plate and the substrate on the mounting plate. And a substrate vacuum pump that holds the substrate by vacuum suction onto the mounting plate.
The vacuum pump drive means 25 drives the vacuum pump 24.

  The display screen output unit 26 outputs, for example, image data for each substrate transfer intermediate position of the exposure apparatus 1 to the exposure state display monitor 6 based on the information related to the substrate region supplied from the control device 5 and the information related to the exposure processing. To do. The substrate transfer midway position is, for example, a loading hand (substrate gripping mechanism not shown), a loading conveyor (roller 8), an exposure unit surface plate (table 9), a discharge conveyor (roller 11), or the like. The display screen output unit 26 outputs image data indicating the alignment state between the substrate and the mask 10 to the alignment state display monitor 7 based on the multi-value data output from the imaging unit 20 to the control device 5. .

  The control device 5 is composed of a PC, for example, and includes a control unit 31 and a memory 32. The control unit 31 includes an image processing unit 33, a mark position error calculation unit 34, an inter-mark distance calculation unit 35, and a determination unit 36.

The image processing unit 33 detects the positions of the alignment marks (mask mark Mm and substrate mark Wm) respectively provided on the mask and the substrate by performing image processing on the multivalued data output from the photographing unit 20. . The position of the alignment mark detected by the image processing unit 33 is output to the mark position error calculation unit 34 and the inter-mark distance calculation unit 35 as position information.
The mark position error calculation unit 34 is based on the position information output from the image processing unit 33, and is an alignment distance that is a position error of the alignment mark (for example, the X direction between the center position of the mask mark Mm and the center position of the substrate mark Wm and (Deviation in the Y direction). The alignment distance calculated by the mark position error calculation unit 34 is output to the determination unit 36 as alignment distance information.
The inter-mark distance calculation unit 35 calculates distances (X direction, Y direction, diagonal direction) between the substrate marks Wm provided at the four corners of the substrate based on the position information output from the image processing unit 33. It is. The distance calculated by the inter-mark distance calculation unit 35 is output to the determination unit 36 as distance information.

  The determination unit 36 (determination unit, error information generation unit) determines whether or not the alignment distance calculated by the mark position error calculation unit 34 is within an allowable range. The determination unit 36 determines whether the expansion / contraction error of the substrate is within an allowable range based on the distance between the substrate marks Wm calculated by the inter-mark distance calculation unit 35. The determination unit 36 generates error information when the error exceeds an allowable range during the determination, and stores the generated error information in the memory 32.

  Next, the configuration of the stocker 4 will be described with reference to FIG. The configuration of the stocker 4 is shown in FIGS. 3 (a) and 3 (b). The stocker 4 includes four circular columns 41 that are erected, and a top frame 42 and a bottom frame 43 that fix the four columns 41 at predetermined positions above and below, respectively. One of the four struts 41 is a feed strut 41a, and a feed screw 44 is threaded on the surface thereof. The remaining three columns 41b to 41d are guide columns having a smooth surface. Between the top frame 42 and the bottom frame 43, a guide roller 45 for transporting the substrate W is arranged in parallel to the top frame 42 at a predetermined interval from the top frame 42 and penetrates the stocker 4. ing. Further, between the top frame 42 and the bottom frame 43, a plate-like bracket 46 for receiving a defective substrate is disposed substantially parallel to the guide roller 45 through the four columns 41. .

  As shown in FIG. 3B, the bracket 46 has a hole 47 having a size that allows the guide roller 45 to be pulled out at the center. Around the hole 47, stepped substrate receiving portions 48a are formed on both sides in the traveling direction of the substrate W, and the substrate is extended in a horizontal right-angle direction from one end (unloading direction) of the substrate receiving portion 48a. The stop portion 48 b can receive the substrate W entering the hole portion 47. In the four corners of the bracket 46, four through holes 49 through which the support column 41 passes are provided. Of these through-holes 49, the through-holes 49a that engage with the feed struts 41a are threaded so as to be screwed into the feed screws 44 of the feed struts 41a. A plurality of brackets 46 are arranged via spacers 50 arranged on the support column 41.

  As shown in FIG. 3A, the feed post 41a is connected to a bracket drive means 27 having a gear and a motor, and the bracket drive means 27 rotates the feed post 41a to feed the feed post 41a. The bracket 46 screwed to the feed screw 44 of the support column 41a through the through hole 49a is configured to be screwed and moved upward. The bracket driving means 27 is driven under the control of the control device 5.

  In the exposure apparatus 1 configured as described above, the substrate carried into the exposure apparatus 1 is transported on the roller 8 (8A) as shown in FIG. 1, and the mask 10A is placed on the table 9A of the surface exposure unit 2A. After the alignment process is performed, the surface exposure process is performed, and the wafer is transferred to the work reversing unit 3 and reversed. Further, after being conveyed on the roller 8B and being subjected to alignment processing with the mask 10B on the table 9B of the back surface exposure unit 2B, back surface exposure processing is performed, and the stocker 4 adjacent to the back surface exposure unit 2B is moved. It passes through and is carried out of the apparatus 1.

  On the other hand, when the defective substrate W is transported on the guide roller 45 (see FIG. 3), the bracket driving means 27 is driven by the control of the control device 5, and the bracket 46 at a predetermined position is the same height as the guide roller 45. The defective substrate W is recovered by the bracket 44 that has been moved by being screwed to the position and moved to the same height as the guide roller 45, and the bracket 46 that has recovered the defective substrate W is further moved to a position of a predetermined height. Be made. Thereafter, each time the defective substrate W is sent, the bracket 46 is screwed and moved, and the defective substrates W are sequentially collected. In this way, the defective substrates W can be stored in the stocker 4 in the order of being carried out.

Next, the operation of the control unit 31 of the control device 5 will be described with reference to FIG. FIG. 4 is a flowchart showing the processing of the control unit 31 when the substrate is divided into a plurality of (for example, four) regions in advance for exposure and the exposure processing is executed for each region.
When the processing is started, first, the exposure apparatus 1 receives a substrate from an unillustrated inlet (step 401). Note that, for example, 100 to 1000 substrates are sequentially inserted as the number of substrates in one lot (series). The loaded substrate is transported on the roller 8 and placed on the table 9. The control unit 31 increments the input substrate number m whose initial value is 0 (increment by +1), writes the value in the memory 32, and writes the surface variable i = 1 and the area variable j = 1 in the memory 32. (Step 402). Here, the surface variable i = 1 represents the surface of the substrate, and the surface variable i = 2 represents the back surface of the substrate. Further, in this embodiment, the substrate (rectangle) is divided into four in a square shape, and the region variable j is set to j = 1 to 4 corresponding to the four regions (region 1 to region 4). Has been.

  Subsequently, the exposure apparatus 1 moves the table 9 upward in the Z direction by the table driving means 23 to bring the substrate into contact with the mask 10 (step 403). In this state, the CCD driving means 21 slides the four CCD cameras constituting the photographing means 20 on the moving rail and stops them at predetermined positions at the four corners of the region j (step 404). Subsequently, the imaging means 20 images the alignment marks (substrate mark Wm and mask mark Mm) at the four corners of the region j (step 405). The captured alignment marks at the four corners are displayed on the alignment state display monitor 7 as shown in FIG.

Returning to the flowchart of FIG. 4 again, the mark position error calculator 34 of the controller 31 calculates the alignment distance between the mask mark Mm of the mask 10 and the substrate mark Wm of the substrate (step 406). Subsequently, the determination unit 36 determines whether or not the alignment condition is normal (step 407). The alignment condition is, for example, that the deviation in the X direction between the center position of the mask mark Mm and the center position of the substrate mark Wm is within a predetermined range, and the Y between the center position of the mask mark Mm and the center position of the substrate mark Wm. This is in combination with the deviation of the direction being within a predetermined range.
When the position of the alignment mark cannot be recognized due to a defect in the alignment mark (substrate mark Wm), a deviation in the formation position, etc., the alignment distance is not calculated, and it is determined that the alignment condition is not normal.

  If it is determined in step 407 that the alignment condition is normal, the exposure apparatus 1 performs exposure processing for the corresponding region j by the exposure unit 22 (step 408). Note that the substrate and the mask 10 are brought into close contact with each other before performing the exposure process. That is, the space between the translucent plate and the table 9 is edge-sealed between the frame of the translucent plate on which the mask 10 is mounted and the table 9, and is sucked by the vacuum pump 24 (main vacuum pump). . Further, the shielding plate that shields the portion other than the region j of the substrate moves on the light transmitting plate to shield the portion other than the region j. Then, after exposure for a predetermined time by the light irradiation mechanism, the shielding plate moves to the original position, and the vacuum contact state between the substrate and the mask 10 is released.

  Subsequent to step 408, the control unit 31 writes processed information indicating that the exposure processing of the region j is completed to the memory 32 (step 409), and whether or not the region variable j has reached the maximum value (4). Is determined (step 410). If the area variable j has reached the maximum value (4), the exposure process for the corresponding surface of the substrate has been completed, and the controller 31 subsequently determines whether the surface variable i is “2” ( It is determined whether or not the substrate being processed is the back side (step 411). If the surface variable i is “2”, the double-sided exposure process has been completed, and the substrate is discharged as a non-defective product (step 412). Subsequently, the control unit 31 determines whether or not the input substrate number m has reached a predetermined value (number of sheets in one lot) (step 413). If the input substrate number m has reached a predetermined value (number of sheets in one lot), the process ends. If not, the process returns to step 401.

  On the other hand, when the surface variable i is not “2” in step 411 (when i = 1), the exposure apparatus 1 transports the substrate to the work reversing unit 3 and performs reversal processing (step 414). Is sent to the back exposure unit 2B. Subsequently, the control unit 31 writes the surface variable i = 2 and the region variable j = 1 in the memory 32 (step 415), and returns to the process of step 404 to execute the back surface exposure process.

  If the region variable j does not reach the maximum value (4) in step 410, the control unit 31 increments the region variable j (+1 step) in order to perform exposure processing for the next unexposed region. The value is written into the memory 32 (step 416), and the process returns to step 404.

  In the alignment process in step 407, if it is determined that the alignment condition is not normal, the substrate ID (identification number) and the unexposed area are on the front surface (i = 1) or on the back surface (i = 2), where is the region j, and what is the reason for the error (whether the alignment mark could be recognized, etc.) is acquired as error information. The ID may be the input board number m. In this case, the control unit 31 performs processing according to the flowchart shown in FIG. That is, when the alignment condition is not normal, the control unit 31 increments the retry count R whose initial value is 0 (+1 step) and writes the value in the memory 32 (step 501). The retry count R represents the number of times table adjustment (step 511) described later has been tried.

  Following step 501, the control unit 31 determines whether or not the number of retries R has reached a predetermined number (for example, three times) (step 502). When the number of retries R has reached a predetermined number (for example, 3 times), the error information is written in the memory 32 (step 503).

  Subsequently, the control unit 31 determines whether or not the region variable j has reached the maximum value (4) (step 504). If the area variable j has reached the maximum value (4), it is subsequently determined whether or not the surface variable i is “2” (whether the substrate being processed is the back surface) (step 505). When the surface variable i is “2”, the control unit 31 stores the substrate being processed in the stocker 4 for reprocessing (step 506), and information indicating that the substrate is stored in the stocker 4. The stored information is written in the memory 32 (step 507), and the process returns to the process of step 401 shown in FIG.

  On the other hand, if the surface variable i is not “2” in step 505 (i = 1), the exposure apparatus 1 transports the substrate to the work reversing unit 3 and performs reversal processing (step 508), and thereafter. The substrate is sent to the back exposure unit 2B. Subsequently, the control unit 31 writes the plane variable i = 2 and the area variable j = 1 in the memory 32 (step 509), and returns to the process of step 404 shown in FIG.

  If the region variable j does not reach the maximum value (4) in step 504, the control unit 31 increments the region variable j (+1 step) in order to expose the next unexposed region. The value is written in the memory 32 (step 510), and the process returns to the process of step 404 shown in FIG.

  In step 502, when the number of retries R has not reached the predetermined number, the exposure apparatus 1 uses the table driving means 23 to move the table 9 downward in the Z direction to mask the substrate placed on the table 9. Separate from 10. Subsequently, the exposure apparatus 1 adjusts the position of the table 9 in the XYθ directions by the table driving unit 23 based on the position error (alignment distance) calculated by the mark position error calculation unit 34 (step 511). As a result, the placement plate above the table 9 on which the substrate is placed is moved to a new alignment position in the horizontal direction by the movement of the X direction moving unit, the Y direction moving unit, and the θ direction moving unit below the table 9. Moved to. Subsequently, the processing returns to step 403 shown in FIG. 4 in order to calculate the matching distance again.

  Next, another embodiment of the operation of the control unit 31 of the control device 5 will be described with reference to FIG. This embodiment is an embodiment in which the exposure process is performed on the entire area of the substrate in a lump. The substrate is divided into a plurality of (for example, four) regions in advance. FIG. 6 is a flowchart showing processing of the control unit 31 in this case.

  When the processing is started, first, the exposure apparatus 1 receives a substrate from a loading port (not shown) (step 601). The loaded substrate is transported on the roller 8 and placed on the table 9. At this time, the control unit 31 increments the input substrate number m whose initial value is 0 (increment by +1), writes the value in the memory 32, and writes the surface variable i = 1 in the memory 32 (step 602). ).

  Subsequently, the exposure apparatus 1 moves the table 9 upward in the Z direction by the table driving unit 23 to bring the substrate into contact with the mask 10 (step 603). The CCD driving means 21 slides the four CCD cameras on the moving rail and stops them at predetermined positions at the four corners of the substrate (step 604). Subsequently, an alignment mark is photographed by the photographing means 20 (step 605).

  The inter-mark position calculation unit 35 of the control unit 3 calculates the distance between the alignment marks (X direction, Y direction, diagonal direction) (step 606). Subsequently, the determination unit 36 determines whether or not the alignment condition is normal (step 607). That is, it is determined whether or not the distance between the substrate marks Wm is within a predetermined range (normal). If it is determined that the alignment conditions are normal, the exposure apparatus 1 performs an exposure process for the entire substrate (step 608).

  Subsequent to step 608, the control unit 31 writes processed information indicating that the exposure process for one surface of the substrate is completed in the memory 32 (step 609). Then, it is determined whether or not the surface variable i is “2” (whether the substrate being processed is the back surface) (step 610). If the surface variable i is “2”, the exposure apparatus 1 discharges the substrate as a non-defective product (step 611). Subsequently, the control unit 31 determines whether or not the input board number m has reached a predetermined value (number of sheets in one lot) (step 612). If the input substrate number m has reached a predetermined value (number of sheets in one lot), the process is terminated. If not, the process returns to step 601.

  On the other hand, when the surface variable i is not “2” in step 610 (i = 1), the exposure apparatus 1 transports the substrate to the work reversing unit 3 and performs reversal processing (step 613). Is sent to the back exposure unit 2B. Subsequently, the control unit 31 writes the surface variable i = 2 in the memory 32 (step 614), and returns to the processing in step 603 to execute the back surface exposure processing.

  If it is determined in step 607 that the alignment condition is not normal, the exposure apparatus 1 executes alignment processing and exposure processing for each of the four areas (j = 1 to 4). For this purpose, the control unit 31 sets the area variable j to 1 and writes it in the memory 32 (step 615). Subsequently, the processing proceeds to step 404 shown in FIG. 4, and the subsequent processing is executed. However, when the process proceeds from step 615 to step 404 as described above, if the result of step 404 is NO in step 413, the process proceeds to step 601 and the process proceeds to step 601 following step 415. That is, the exposure apparatus 1 performs exposure processing on the entire area of the substrate for one lot of substrates, and performs alignment processing and exposure processing for each divided area of the substrate only on the surface where the alignment conditions of the entire substrate are not normal. Shall be executed.

  In step 606, the mark position error calculation unit 34 of the mask 10 does not calculate the distance between the alignment marks (X direction, Y direction, diagonal direction). The matching distance between the mask mark Mm and the substrate mark Wm of the substrate may be calculated. In this case, the alignment conditions in step 607 are, for example, that the deviation in the X direction between the center position of the mask mark Mm and the center position of the substrate mark Wm is within a predetermined range, and the center position of the mask mark Mm and the substrate. The deviation in the Y direction from the center position of the mark Wm is within a predetermined range.

  As described above, the embodiment in the case where the alignment process and the exposure process are performed on the divided areas of the substrate from the beginning (the process shown in the flowcharts of FIGS. 4 and 5) and the exposure process on the entire area of the substrate first. When the alignment process and the exposure process are executed in a small area divided when it is impossible to execute the process (the process shown in the flowchart of FIG. 6 and the process shown in the flowcharts of FIGS. 4 and 5) Explained the form. In the above-described two embodiments, after one substrate is loaded, subjected to exposure processing and discharged or stored in the stocker 4, the next substrate is loaded. When the exposure process is finished, the next substrate may be loaded.

  In the two embodiments, the substrate on which the alignment process and the exposure process are performed and the unexposed area is present is stored in the stocker 4 by the bracket driving means 27 under the control of the control apparatus 5 and is also controlled by the control apparatus. 5 is written in the memory 32. An example of error information written in the memory 32 is shown in FIG. In this example, the substrate number (substrate ID) is No. The error information of 1 is that the surface area 1 has not been exposed (x mark in the figure) and the other areas have been exposed (circle mark in the figure), and the alignment mark was correctly recognized in the alignment process. (OK in the figure) is shown. This is because the alignment mark is correctly recognized in the alignment process, but an error occurs because the determination unit 36 of the control device 5 determines that the alignment distance exceeds the allowable range, and the surface area 1 is not exposed. It has become.

  Similarly, the board number is No. The error information 2 indicates that the back surface area 3 and area 4 have not been exposed and the alignment mark could not be recognized (NG in the figure) and that the other areas have been exposed. . This is because the alignment distance is not calculated in the alignment process because the alignment mark is not recognized because of a defect or the like, an error occurs, and the back surface region 3 and region 4 are not exposed. . Furthermore, the board number is No. The error information of N indicates that the area 2 and area 3 on the front surface are unprocessed, the area 2 on the back surface is unprocessed, the other areas are exposed, and the alignment mark is correctly recognized. (OK in the figure) is shown. This is because the alignment mark was correctly recognized in the alignment process, but an error occurred because the alignment distance exceeded the allowable range, and an unexposed area was generated.

Next, another embodiment of the operation of the control unit 31 of the control device 5 will be described with reference to FIG. In this embodiment, after the alignment process and the exposure process for the number of (series) substrates in one lot are completed, the substrate stored in the stocker 4 (the substrate in which the unexposed region is present) is re-introduced into the exposure apparatus 1. It is an embodiment in the case of doing. FIG. 9 is a flowchart showing processing of the control unit 31 in this case.
It is assumed that the substrates stored in the stocker 4 in the order in which they are carried out are reloaded into the exposure apparatus 1 in the order in which they are carried out (the order in which they are stored). In addition, as a method of transferring the substrate to be recharged to the substrate loading line at the front stage of the exposure apparatus 1, the entire stocker 4 may be transported or removed from the stocker 4 by an operator and transported.

  When the substrate is loaded, the control means 31 reads error information stored in the memory 32 (step 901). That is, the error information reads whether the unexposed area is on the front side or the back side, where is the area, and what is the reason for the error.

  Subsequently, the control unit 31 determines whether or not the alignment mark could be recognized when the previous error occurred as the reason for the error (step 902). If the alignment mark can be recognized in the corresponding area when the previous error occurred (step 902 YES), the exposure apparatus 1 performs the alignment operation for the entire area of the substrate (step 903). That is, the control unit 31 moves the CCD camera to each of the four corners of the substrate, photographs the alignment marks at each corner, calculates the distance between the alignment marks in the X direction, the Y direction, and the diagonal direction, It is determined whether or not the distance between the marks is within a predetermined range (normal or not) (step 904).

  If it is determined in step 904 that the distance between the alignment marks is within a predetermined range (normal), the exposure apparatus 1 performs an alignment operation for the corresponding area in which the previous error occurred (step 905). That is, the control unit 31 moves the CCD camera to each of the four corners of the corresponding area (divided small area) of the substrate, photographs the alignment mark at each corner, and sets the center of the substrate mark Wm and the mask mark Mm. The distances in the X direction and the Y direction from the center are calculated to determine whether the distance is within a predetermined range (normal or not) (step 906).

  If the alignment distance between the substrate mark Wm and the mask mark Mm is within a predetermined range (normal) (YES in step 906), the control unit 31 performs an exposure process on the area (step 907), and the exposure process has been performed. Is written in the memory 32 (step 908).

  Subsequently, the control unit 31 refers to the error information to determine whether or not the unprocessed area is still included in the currently processed substrate (step 909). If there is another unexposed area, the process returns to step 905. If there is no other unexposed area, the substrate is discharged as a non-defective product (step 910). Subsequently, the control unit 31 determines whether there is still a substrate that has not been processed (whether all re-inserted substrates have been input) (step 911). If all of the re-inserted substrates have been input, the process ends. If not, the process returns to step 901 to process the next substrate.

  If the alignment distance between the substrate mark Wm and the mask mark Mm is not within the predetermined range (normal) in step 906, the control unit 31 refers to the error information and exposes the substrate currently being processed. It is determined whether or not an unprocessed area is still included (step 912). If there is another unexposed area, the process returns to step 905. If there is no other unprocessed area, the substrate is discharged as a defective product (step 913), and the process returns to step 901.

  In step 904, when the distance between the alignment marks is not within the predetermined range (not normal), the process proceeds to step 912 and the substrate is discharged as a defective product. In step 902, when the alignment mark cannot be recognized when the previous error occurs, the entire substrate alignment process is skipped, and the process proceeds to step 905 to execute the alignment process for the corresponding area in which the error occurred. To do.

  In step 903, the mark position error calculation unit 34 of the mask 10 instead of the inter-mark position calculation unit 35 of the control unit 3 calculating the distance between the alignment marks (X direction, Y direction, diagonal direction). The alignment distance between the mask mark Mm and the substrate marks Wm at the four corners of the substrate may be calculated. In this case, in the determination process in step 904, it is determined whether or not the alignment condition is normal. The alignment conditions at this time are, for example, that the deviation in the X direction between the center position of the mask mark Mm and the center position of the substrate mark Wm is within a predetermined range, the center position of the mask mark Mm, and the center position of the substrate mark Wm. And a deviation in the Y direction within a predetermined range.

  As described above, when the alignment process and exposure process for the number of substrates in one lot are completed and a substrate having an unexposed area stored in the stocker 4 is re-inserted into the exposure apparatus 1, the exposure is not performed. The alignment process and the exposure process are executed only in the processing area. Therefore, it is possible to make use of the substrate once determined to be unexposure by the control device 5 and to improve the yield.

  Next, the exposure state display monitor 6 (6A, 6B) of the exposure apparatus 1 will be described with reference to FIGS. 10 and 11 are examples of display screens of the exposure state display monitor 6. In the screen example shown in FIG. 10, information indicating which position of the substrate is present is displayed among the substrate transfer intermediate positions in the processing steps from loading to discharging of the substrate. In order to indicate the substrate transfer midway position, a loading hand position display area 1001, a loading conveyor position display area 1002, an exposure unit surface plate position display area 1003, a discharge conveyor position display area 1004, and a loading hand position display area 1005 are provided. . As a result, the exposure state display monitor 6 displays which processing step the substrate having the predetermined ID (identification number) is currently in, and which region of the substrate is the unexposed region at that position. The information indicating is displayed. In this example, the ID is set to No. by the display of the exposure unit surface plate position display area 1003. 6 is present at the position of the exposure unit surface plate (table 9), and it is recognized that the front surface of the substrate is all exposed and the back surface is unprocessed.

  Further, the screen example shown in FIG. 11 displays only information relating to the substrate located on the exposure unit surface plate. On the screen, an attention display area 1101 for prompting attention when there is an unprocessed area, operation buttons 1102 to 1104, and a substrate display area 1105 are provided. In this example, it is recognized from the display in the substrate display area 1105 that a quarter of the front surface of the substrate is unexposed and the back surface is all exposed.

  As described above, in the exposure apparatus 1 of the present embodiment, the information regarding the substrate area and the error information stored in advance in the memory 32 of the control device 5 are stored, and based on the substrate area and the error information. Thus, the exposure state display monitor 6 can display information indicating which part on the substrate is an unexposed region. Therefore, when the substrate having an error in the first alignment process and the exposure process (the substrate in which the unexposed area is present) is reintroduced, it can be easily determined by the exposure state display monitor 6 which area is unprocessed. Can be determined.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to the said embodiment. For example, in the present embodiment, in the process of the control unit 31 (the process shown in FIGS. 4 to 6) when the substrate is first inserted, the alignment condition is that the center position of the mask mark Mm and the center position of the substrate mark Wm. Although described as a condition that the deviation in the X direction or the Y direction is within a predetermined range, the alignment condition is, for example, the image sample information such as the outer dimensions of the substrate, the shape of the alignment mark, the color / reflectance of the alignment mark, the substrate It may be a distance from the peripheral edge to the alignment mark, a vacuum pressure value at the time of substrate adsorption (during conveyance), or the like.

  Further, as the alignment condition, a strict first condition and a second condition that is looser than the first condition may be provided. In this case, the exposure apparatus 1 executes the exposure process as it is when the first condition is cleared, and determines whether the second condition can be cleared when the first condition cannot be cleared. When the second condition is cleared, an exposure process is executed, and when the second condition cannot be cleared, the substrate is stored in the stocker 4. By doing so, it is possible to specify the cause of the error when an error that the exposure is not performed occurs. Examples of such error causes include contamination around the substrate mark Wm of the substrate, adhesion of foreign matter to the mask, substrate warping (abnormality of the degree of vacuum), and the like. Among these, in the case of dirt or foreign matter adhering, by removing the cause, the exposure process can be normally executed when the substrate is again put into the exposure apparatus 1, so that the yield is improved. be able to.

1 is an external view of an exposure apparatus according to the present invention. It is a block diagram which shows the structure of the surface exposure part of the exposure apparatus which concerns on this invention. It is explanatory drawing for demonstrating a stocker, (a) is a block diagram of a stocker, (b) is a disassembled perspective view of a part of stocker. It is a flowchart which shows the process of the control part in the case of dividing a board | substrate into a some area | region beforehand and performing an exposure process for every area | region. FIG. 5 is a flowchart (continuation of FIG. 4) showing processing of the control unit when the substrate is divided into a plurality of regions in advance and exposure processing is executed for each region. It is a flowchart which shows the process of the control part in the case of performing exposure processing collectively in the area | region of the whole board | substrate. It is a figure which shows an example of the alignment display screen of a mask mark and a board | substrate mark. It is a figure which shows an example of the error information memorize | stored in memory. It is a flowchart which shows the process of the control part when a board | substrate is thrown in again. It is a figure which shows an example of the display screen showing the process process from injection | emission to discharge | emission. It is a figure which shows an example of the display screen of an exposure part surface plate.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Exposure apparatus 2A Front surface exposure part 2B Back surface exposure part 3 Workpiece inversion part 4 Stocker 5 Control apparatus 6 Exposure state display monitor (display part)
7 Alignment Status Display Monitor 8 Roller 9 Table 10 Mask 20 Imaging Means 21 CCD Driving Means 22 Exposure Means 23 Table Driving Means 24 Vacuum Pump 25 Vacuum Pump Driving Means 26 Display Screen Output Means 27 Bracket Driving Means 31 Control Unit (Exposure Processing Control Means) )
32 memory (storage means)
33 Image processing unit 34 Mark position error calculation unit 35 Distance between mark calculation unit 36 Determination unit (determination unit, error information generation unit)

Claims (4)

In an exposure apparatus that performs alignment processing and exposure processing for the entire area of the substrate or for each area that is pre-divided for exposure,
A discriminating unit for discriminating whether or not the substrate can be exposed based on both the substrate mark formed on each of the substrate and a mask having a pattern formed on the substrate and the both marks obtained by photographing the mask mark by an imaging unit; ,
Storage means for storing, as error information, information relating to the substrate that has been determined to be non-exposure by the determining means, and information relating to an unexposed area that is determined to be non-exposure on the substrate;
Based on the error information stored in the storage means when the substrate in which the unexposed area is present is re-input after completing the alignment process and the exposure process for a series of substrate numbers, the unexposed process is performed. Exposure processing control means for controlling the region to perform the alignment processing and exposure processing;
An exposure apparatus comprising:   A display unit is provided for displaying information indicating which part of the substrate is the unexposed region based on the pre-divided region of the substrate stored in the storage unit and the error information. The exposure apparatus according to claim 1. In an exposure method for performing alignment processing and exposure processing for the entire region of the substrate or for each region that is pre-divided for exposure,
A discriminating step for discriminating whether or not the substrate can be exposed based on the substrate mark formed on each of the substrate and a mask having a pattern formed on the substrate and the both marks obtained by photographing the mask mark by a photographing unit; ,
Storing, as error information, information relating to the substrate that has been determined to be non-exposure by this determination step, and information relating to an unprocessed region that is determined to be non-exposure on this substrate;
When the substrate in which the unexposed area is present is re-entered after completing the alignment process and the exposure process for a series of substrate numbers, the alignment process and the unexposed area are performed based on the error information. An exposure process control step for controlling the exposure process to be executed;
An exposure method comprising: In order to perform the alignment process and the exposure process for the entire area of the substrate or each area pre-divided for exposure,
Discriminating means for discriminating whether or not the substrate can be exposed based on both the substrate mark formed on each of the substrate and a mask having a pattern to be formed on the substrate and the both marks obtained by photographing the mask mark by an imaging means;
Error information generating means for generating, as error information, information relating to the substrate that has been determined to be non-exposure by the determining means, and information relating to an unexposed area that is determined to be non-exposure on the substrate;
Based on the error information generated by the error information generating means when the substrate in which the unexposed area is present is re-inserted after completing the alignment process and the exposure process for a series of substrate numbers, the exposure is performed. Exposure process control means for controlling the unprocessed area to perform the alignment process and the exposure process;
Functioning as an exposure processing program.

Images