CN110783246B - Alignment method - Google Patents

Alignment method Download PDF

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Publication number
CN110783246B
CN110783246B CN201910674919.1A CN201910674919A CN110783246B CN 110783246 B CN110783246 B CN 110783246B CN 201910674919 A CN201910674919 A CN 201910674919A CN 110783246 B CN110783246 B CN 110783246B
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unit
wafer
alignment mark
image
macro
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CN110783246A (en
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宫田谕
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Disco Corp
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Disco Corp
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/67—Apparatus specially adapted for handling semiconductor or electric solid state devices during manufacture or treatment thereof; Apparatus specially adapted for handling wafers during manufacture or treatment of semiconductor or electric solid state devices or components ; Apparatus not specifically provided for elsewhere
    • H01L21/68—Apparatus specially adapted for handling semiconductor or electric solid state devices during manufacture or treatment thereof; Apparatus specially adapted for handling wafers during manufacture or treatment of semiconductor or electric solid state devices or components ; Apparatus not specifically provided for elsewhere for positioning, orientation or alignment
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/67—Apparatus specially adapted for handling semiconductor or electric solid state devices during manufacture or treatment thereof; Apparatus specially adapted for handling wafers during manufacture or treatment of semiconductor or electric solid state devices or components ; Apparatus not specifically provided for elsewhere
    • H01L21/68—Apparatus specially adapted for handling semiconductor or electric solid state devices during manufacture or treatment thereof; Apparatus specially adapted for handling wafers during manufacture or treatment of semiconductor or electric solid state devices or components ; Apparatus not specifically provided for elsewhere for positioning, orientation or alignment
    • H01L21/681—Apparatus specially adapted for handling semiconductor or electric solid state devices during manufacture or treatment thereof; Apparatus specially adapted for handling wafers during manufacture or treatment of semiconductor or electric solid state devices or components ; Apparatus not specifically provided for elsewhere for positioning, orientation or alignment using optical controlling means
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
    • H01L21/04—Manufacture or treatment of semiconductor devices or of parts thereof the devices having at least one potential-jump barrier or surface barrier, e.g. PN junction, depletion layer or carrier concentration layer
    • H01L21/18—Manufacture or treatment of semiconductor devices or of parts thereof the devices having at least one potential-jump barrier or surface barrier, e.g. PN junction, depletion layer or carrier concentration layer the devices having semiconductor bodies comprising elements of Group IV of the Periodic System or AIIIBV compounds with or without impurities, e.g. doping materials
    • H01L21/30—Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26
    • H01L21/302—Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26 to change their surface-physical characteristics or shape, e.g. etching, polishing, cutting
    • H01L21/304—Mechanical treatment, e.g. grinding, polishing, cutting
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/67—Apparatus specially adapted for handling semiconductor or electric solid state devices during manufacture or treatment thereof; Apparatus specially adapted for handling wafers during manufacture or treatment of semiconductor or electric solid state devices or components ; Apparatus not specifically provided for elsewhere
    • H01L21/67005—Apparatus not specifically provided for elsewhere
    • H01L21/67242—Apparatus for monitoring, sorting or marking
    • H01L21/67259—Position monitoring, e.g. misposition detection or presence detection
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/67—Apparatus specially adapted for handling semiconductor or electric solid state devices during manufacture or treatment thereof; Apparatus specially adapted for handling wafers during manufacture or treatment of semiconductor or electric solid state devices or components ; Apparatus not specifically provided for elsewhere
    • H01L21/67005—Apparatus not specifically provided for elsewhere
    • H01L21/67242—Apparatus for monitoring, sorting or marking
    • H01L21/67282—Marking devices
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/70—Manufacture or treatment of devices consisting of a plurality of solid state components formed in or on a common substrate or of parts thereof; Manufacture of integrated circuit devices or of parts thereof
    • H01L21/71—Manufacture of specific parts of devices defined in group H01L21/70
    • H01L21/76—Making of isolation regions between components
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/70—Manufacture or treatment of devices consisting of a plurality of solid state components formed in or on a common substrate or of parts thereof; Manufacture of integrated circuit devices or of parts thereof
    • H01L21/77—Manufacture or treatment of devices consisting of a plurality of solid state components or integrated circuits formed in, or on, a common substrate
    • H01L21/78—Manufacture or treatment of devices consisting of a plurality of solid state components or integrated circuits formed in, or on, a common substrate with subsequent division of the substrate into plural individual devices

Abstract

An alignment method is provided for quickly finding an alignment mark when determining a division predetermined line. The alignment method uses a photographing unit (51) to photograph a wafer (W) formed with a device (D) in a region divided by a 1 st division scheduled line (S1) and a 2 nd division scheduled line (S2), detects an alignment Mark (MA) and determines the 1 st division scheduled line and the 2 nd division scheduled line, wherein the alignment method comprises the following steps: a step of registering a target image (GT) including an alignment Mark (MA) in an area smaller than the imaging area (510), wherein the imaging area (510) of the imaging means is smaller than the imaging area; and a step of combining at least two side-by-side captured images obtained by capturing the wafer (W) held by the stage (30) with the capturing means to form a combined image, wherein each time the combined image is formed, pattern matching is performed in the combined image to confirm the presence or absence of the target image (GT), and after the target image (GT) is detected, the 1 st division scheduled line and the 2 nd division scheduled line are determined based on the alignment Mark (MA) in the target image (GT).

Description

Alignment method
Technical Field
The present invention relates to an alignment method for determining a dividing line of a wafer.
Background
When performing a cutting process of forming a cutting groove by cutting a cutting tool along a line to cut a wafer having a device formed in a region divided by the line to cut, or a laser process of forming a processing groove by irradiating a laser beam along the line to cut, the apparatus needs to identify the line to cut.
The same circuit pattern is formed on the device front side of the wafer. And, one pattern having a feature shape among the circuit patterns is set as a macro alignment mark. Further, a microscopic alignment mark smaller than the macroscopic alignment mark is set at a position distant from the macroscopic alignment mark by a predetermined distance in a predetermined direction. The predetermined dividing line is set at a position distant from the microscopic alignment mark by a predetermined distance in a predetermined direction.
In the macro alignment, the processing apparatus, after finding the macro alignment mark of the wafer held by the chuck table, uses the macro alignment mark to perform rough θ alignment for aligning the line to be divided substantially parallel to the X-axis direction, which is one axis on the horizontal plane (for example, refer to patent document 1). Next, a microscopic alignment mark located at a predetermined distance from the macroscopic alignment mark in the predetermined direction is checked, and the microscopic alignment mark is used to perform high-precision θ alignment for aligning the line to be divided in parallel with the X-axis direction with high precision. Then, a division line is identified which is a predetermined distance from the microscopic alignment mark in a predetermined direction.
Patent document 1: japanese patent laid-open No. 2007-088028
As preparation for macro alignment, a macro alignment mark is photographed with a photographing unit having a photographing area smaller than an area divided by a division predetermined line (i.e., a photographing area smaller than the size of a device), and a target image smaller than the photographing area and centered on the macro alignment mark is registered in a processing apparatus.
In macro alignment, whether or not the target image is present in a photographed image obtained by photographing a wafer to be processed after being newly sucked and held by the chuck table by the photographing unit is pattern-matched. That is, for example, the target image is moved pixel by pixel in the captured image to perform pattern matching. Then, if there is no target image in the captured image, the number of pixels of the target image is repeated to capture the adjacent position of the previous captured position, a new captured image is formed, and pattern matching of the target image is performed in the new captured image, thereby finding out the macro alignment mark.
In this way, before the macro alignment mark is found, the movement of the imaging position (specifically, the movement of the imaging position in a spiral shape on the wafer) and the pattern matching using the target image in the new imaging image imaged by the movement of the imaging position are repeated until the cumulative area of each imaging image imaged by repeating the number of pixels becomes at least the same area as the area divided by the dividing line or more. Such a conventional step of searching for a macro alignment mark is called a spiral search.
In the spiral search, since the imaging area of the imaging unit is enlarged while repeating the number of pixels of the target image, if the target image is large (that is, the macro alignment mark is large), the amount of movement when the imaging unit moves to a position adjacent to the previous imaging position is reduced. The reason why the number of pixels of the target image is repeated is that the entire target image is not missed in the case where only a part of the target image is displayed in the captured image. Therefore, since the imaging unit is moved to a position adjacent to the previous imaging position by a distance obtained by subtracting the size of the target image from the size of the entire image, when the target image is large, the movement amount of the imaging area is reduced, and therefore, it is necessary to perform imaging a plurality of times by moving the imaging position a plurality of times in a spiral shape, which causes a problem that it takes time to find the macro alignment mark.
Specifically, for example, when the imaging area of the imaging unit is 512×480 pixels, if the macro alignment mark is small in size and the target image is 16×18 pixels, the number of times of imaging accompanied by the spiral movement of the imaging area of the imaging unit ends up, for example, 6 times at maximum. In contrast, if the macro alignment mark is large in size and the target image is 250×250 pixels, the number of shots associated with the spiral movement of the imaging region of the imaging unit is up to 25, for example.
Disclosure of Invention
In this way, in the alignment method for determining the dividing lines of the wafer, there is a problem that the alignment time is shortened by quickly searching for the alignment mark (macro alignment mark).
In order to solve the above-described problems, the present invention provides an alignment method for holding a wafer having a device formed in a region defined by a 1 st division line and a 2 nd division line intersecting the 1 st division line, the wafer being held by a chuck table, and detecting an alignment mark disposed in the region by a photographing means to determine the 1 st division line and the 2 nd division line, the alignment method comprising: a registration step of registering a target image including an alignment mark in a region smaller than a photographing region of the photographing unit, the photographing region being smaller than the photographing region; and a confirmation step of combining at least two side-by-side captured images obtained by capturing the wafer newly held on the chuck table by the capturing unit to form a combined image, wherein each time the combined image is formed, pattern matching is performed in the combined image to confirm whether the target image is present or not, and if the target image is detected in the confirmation step, the 1 st division predetermined line and the 2 nd division predetermined line are determined based on the alignment mark in the target image.
The alignment method of the present invention performs the following confirmation process: at least two taken images of wafers newly held on a chuck table are combined to form a combined image, and each time the combined image is formed, pattern matching is performed in the combined image to confirm the presence or absence of a target image, thereby eliminating the need for conventionally performing spiral search when searching for an alignment mark of a new wafer to be processed. That is, it is not necessary to perform imaging a plurality of times by moving the imaging region of the imaging means in a spiral manner so as to repeat the number of pixels of the target image as in the conventional technique, and it is not necessary to perform pattern matching of the target image for each of the imaging images imaged by repeating the number of pixels. Thus, the alignment mark (macro alignment mark) can be quickly found to shorten the alignment time.
Drawings
Fig. 1 is a perspective view showing an example of a cutting device for cutting a wafer.
Fig. 2 is an explanatory diagram for explaining a case where a target image including an alignment mark is registered in an area smaller than a photographing area.
Fig. 3 is an explanatory view for explaining a photographed image obtained by photographing a wafer newly held on a chuck table by a photographing unit.
Fig. 4 is an explanatory diagram for explaining a case where two taken images arranged side by side are combined to form a combined image, and pattern matching is performed in the combined image to confirm the presence or absence of a target image.
Fig. 5 is an explanatory diagram for explaining a case where three taken images arranged side by side are combined to form a combined image, and pattern matching is performed in the combined image to confirm the presence or absence of a target image.
Fig. 6 is an explanatory diagram for explaining a case where four captured images arranged side by side are combined to form a combined image, and pattern matching is performed in the combined image to confirm the presence or absence of a target image.
Description of the reference numerals
W: a wafer; wa: the front side of the wafer; s1: 1 st division of a predetermined line; s2: dividing the preset line; d: a device; wb: the back surface of the wafer; f: an annular frame; t: dicing tape; 1: a cutting device; 10: a base station; 14: a gate-type column; 11: a cutting feed unit; 12: an index feeding unit; 16: an infeed unit; 30: a chuck table; 30a: a holding surface; 31: a rotating unit; 6: a cutting unit; 60: a rotation shaft; 61: a housing; 63: a cutting tool; 51: a macro shooting unit; 52: a microscopic photographing unit; 9: a control unit; 91: a storage unit; 92: a combined image forming section; 93: a pattern matching part.
Detailed Description
The cutting device 1 shown in fig. 1 is a device for cutting a wafer W, which is a plate-like workpiece held by the chuck table 30, by rotating a cutting tool 63 included in a cutting unit 6 and cutting the wafer W.
A cutting feed unit 11 is disposed on the base 10 of the cutting device 1, and the cutting feed unit 11 reciprocates the chuck table 30 in a cutting feed direction (X-axis direction). The cutting feed unit 11 includes: a ball screw 110 having an axis in the X-axis direction; a pair of guide rails 111 disposed parallel to the ball screw 110; a motor 112 that rotates the ball screw 110; and a movable plate 113, an internal nut of which is screwed with the ball screw 110, and a bottom of the movable plate 113 is in sliding contact with the guide rail 111. When the motor 112 rotates the ball screw 110, the movable plate 113 is guided by the guide rail 111 and moves in the X-axis direction, and the chuck table 30 disposed on the movable plate 113 moves in the X-axis direction.
The chuck table 30 for holding the wafer W has a circular outer shape, for example, and attracts and holds the wafer W on a horizontal holding surface 30a formed of a porous member or the like. The chuck table 30 is fixed to the movable plate 113 by a rotating unit 31 disposed on the bottom surface side thereof. The rotation unit 31 can support the chuck table 30 and can rotate the chuck table 30 around the axis in the Z-axis direction.
A plurality of jigs 32 for clamping and fixing the ring frame F are arranged around the chuck table 30 at regular intervals in the circumferential direction.
A gate post 14 is erected on the rear side (-X direction side) on the base 10 so as to straddle the cutting feed unit 11. An index feed unit 12 is disposed on the front surface of the gate post 14, and the index feed unit 12 reciprocates the cutting unit 6 in the Y-axis direction. The index feed unit 12 includes: a ball screw 120 having an axis in the Y-axis direction; a pair of guide rails 121 disposed parallel to the ball screw 120; a motor 122 that rotates the ball screw 120; and a movable plate 123, the nut of which is screwed with the ball screw 120, and the side of the movable plate 123 is in sliding contact with the guide rail 121. When the motor 122 rotates the ball screw 120, the movable plate 123 is guided by the guide rail 121 and moves in the Y-axis direction, and the cutting unit 6 disposed on the movable plate 123 via the plunge feed unit 16 performs index feed in the Y-axis direction.
The movable plate 123 is provided with an infeed unit 16, and the infeed unit 16 reciprocates the cutting unit 6 in a Z-axis direction (vertical direction) perpendicular to the holding surface 30a of the chuck table 30. The infeed unit 16 includes: a ball screw 160 having an axis in the Z-axis direction; a pair of guide rails 161 disposed parallel to the ball screw 160; a motor 162 that rotates the ball screw 160; and a support member 163 having a nut screwed with the ball screw 160, and a side portion of the support member 163 slidably contacting the guide rail 161. When the motor 162 rotates the ball screw 160, the support member 163 is guided by the guide rail 161 and moves in the Z-axis direction, and the cutting unit 6 supported by the support member 163 performs plunge feed in the Z-axis direction.
The cutting unit 6 has: a rotation shaft 60 whose axial direction is the Y-axis direction; a housing 61 fixed to a lower end of the support member 163 and rotatably supporting the rotation shaft 60; a motor, not shown, for rotating the rotation shaft 60; and an annular cutting tool 63 attached to the rotary shaft 60, wherein the cutting tool 63 is rotated at a high speed as the rotary shaft 60 is driven to rotate by a motor, not shown.
For example, a macro imaging unit 51 for imaging the wafer W at a low magnification and a micro imaging unit 52 for imaging the wafer W at a high magnification are disposed on the side surface of the housing 61 of the cutting unit 6. The macro shooting unit 51 includes, for example: an imaging element not shown; a low magnification objective lens; and illumination by which light is irradiated to the wafer W sucked and held on the chuck table 30. The microscopic photographing unit 52 includes, for example: an imaging element not shown; an objective lens with high magnification; and illumination by which light is irradiated to the wafer W sucked and held on the chuck table 30. The macro camera unit 51 and the micro camera unit 52 move in the Y-axis direction and the Z-axis direction in association with the cutting unit 6.
For example, the magnification of the high-magnification objective lens is 10 times that of the low-magnification objective lens, and one pixel in the image captured by the macro imaging unit 51 is 10 μm.
The cutting device 1 has, for example, a control unit 9 for controlling the entire device. The control unit 9 is connected to the cutting feed unit 11, the index feed unit 12, the plunge feed unit 16, the rotation unit 31, and the like through wiring, not shown, and controls cutting feed operation of the chuck table 30 in the X-axis direction by the cutting feed unit 11, indexing feed amount of the cutting unit 6 in the Y-axis direction by the index feed unit 12, plunge feed amount of the cutting unit 6 in the Z-axis direction by the plunge feed unit 16, rotation operation of the chuck table 30 by the rotation unit 31, and the like under control of the control unit 9.
Hereinafter, each step of the alignment method according to the present invention in the case of determining the 1 st division scheduled line S1 and the 2 nd division scheduled line S2 of the wafer W cut by the cutting device 1 shown in fig. 1 will be described.
(1) Registration step
The wafer W shown in fig. 1 is, for example, a circular silicon semiconductor wafer, and devices D are formed on the front surface Wa of the wafer W in lattice-like regions divided by vertically intersecting lines to be divided. A dicing tape T having a larger diameter than the wafer W is attached to the back surface Wb of the wafer W. A ring frame F having a circular opening is adhered to an outer peripheral region of the bonding surface of the dicing tape T, and the wafer W is supported by the ring frame F via the dicing tape T, and is operable via the ring frame F.
The predetermined dividing lines extending in the same direction (for example, the X-axis direction in fig. 1) set on the front surface Wa of the wafer W are referred to as 1 st predetermined dividing lines S1, and the predetermined dividing lines extending in the direction perpendicular to the 1 st predetermined dividing lines S1 (the Y-axis direction perpendicular to the X-axis direction on the horizontal plane) on the front surface Wa of the wafer W are referred to as 2 nd predetermined dividing lines S2.
In the registration step, first, the wafer W is sucked and held by the chuck table 30 shown in fig. 1 with the front surface Wa facing upward. Then, the chuck table 30 for holding the wafer W by suction is moved in the X-axis direction by the cutting feed unit 11. Further, the macro imaging unit 51 is moved in the Y-axis direction by the index feed unit 12, and the wafer W is placed in a state in which the substantial center thereof is located directly below the objective lens of the macro imaging unit 51.
Then, the front surface Wa of the wafer W is photographed by the macro photographing unit 51 to form a photographed image.
The size of the photographing region 510 of the macro photographing unit 51 is smaller than the size of the device D, which is a region divided by the 1 st division scheduled line S1 and the 2 nd division scheduled line S2.
Then, the operator selects one of the circuit patterns having the feature shape, which is displayed on the front surface of the device D of the wafer W in the photographed image, as the macro alignment mark MA. The macro alignment mark MA is formed on each device D of the plurality of devices D at the same position, for example, at a corner portion (lower left corner in fig. 2) of the device D. The macro alignment mark MA may be a pattern having a simple shape such as a cross shape shown in fig. 2, or a simple shape such as a circle or a quadrangle. In addition, the macro alignment mark may not be part of the circuit pattern.
Next, the operator selects a part of the features of the element or the wiring formed on the front surface of the device D, which is located at a predetermined distance from the macro alignment mark MA in a predetermined direction, as a micro alignment mark MB that is significantly smaller than the macro alignment mark MA. The microscopic alignment mark MB is formed at the same position, for example, a corner portion (lower right corner in fig. 2) of the device D on each of the plurality of devices D.
The distance and direction from the macro alignment mark MA to the micro alignment mark MB are stored in the storage unit 91 together with the selected micro alignment mark MB. That is, by counting the number of pixels or the like, the microscopic alignment mark MB is stored at a position distant from the macroscopic alignment mark MA in the X-axis direction by a distance Lx1 and distant from the macroscopic alignment mark MA in the Y-axis direction by a distance Ly 1. In addition, a distance Lx2 from the microscopic alignment mark MB to a center line passing through the width center of the 2 nd division scheduled line S2 and a distance Ly2 from the microscopic alignment mark MB to a center line passing through the width center of the 1 st division scheduled line S1 are stored in the storage portion 91.
In addition, the operator registers the macro alignment mark MA in the storage section 91 of the control unit 9 with a rectangular area indicated by a two-dot chain line smaller than the photographing area 510 of the macro photographing unit 51. That is, the target image GT including the entire macro alignment mark MA is stored in the storage unit 91.
The registration step is sometimes referred to as a Teaching process (a Teaching process) of the cutting apparatus 1 shown in fig. 1, and when cutting a plurality of wafers W of the same type, if the registration step is performed once before cutting a first wafer W, the registration step is not required after newly sucking and holding a second and subsequent wafers W by the chuck table 30.
The registration step is not limited to this embodiment. For example, the memory 91 may store device data obtained by tabulating processing conditions corresponding to each type of a plurality of wafers to be processed. The processing conditions are data obtained by integrating, for each type of wafer to be processed, various settings for performing appropriate cutting processing on the wafer, including information of a macro alignment mark and a micro alignment mark for each type of wafer, in addition to a cutting feed speed of the chuck table 30 holding the wafer by the cutting feed unit 11, an index feed amount of the cutting unit 6 by the index feed unit 12, and the like, as shown in fig. 1. Thus, the operator can select appropriate processing conditions of the wafer W shown in fig. 1 from the device data, and register the target image GT including the entire macro alignment mark MA with a region indicated by a two-dot chain line smaller than the imaging region 510 of the macro imaging unit 51. In this case, the macro imaging unit 51 may not be used to image the wafer W in the present registration step.
(2) Confirmation procedure
A new wafer W to be subjected to cutting is sucked and held by the chuck table 30 shown in fig. 1 with the front surface Wa facing upward. The chuck table 30 shown in fig. 1, which attracts and holds a new wafer W, is moved in the X-axis direction by the cutting feed unit 11. In addition, the macro camera unit 51 is moved in the Y-axis direction by the index feed unit 12. The front surface Wa of the wafer W is positioned immediately below the objective lens of the macro imaging unit 51. The imaging position of the front surface Wa of the wafer W by the macro imaging unit 51 is not limited to a specific position as long as it is a region where the device D is formed.
In this state, the front surface Wa of the wafer W is photographed by the macro photographing unit 51 to form a photographed image G1 shown in fig. 3. The size of the photographed image G1 is the same as the size of the photographing region 510 of the macro photographing unit 51 shown in fig. 2, and thus smaller than the size of the device D.
The captured image G1 is stored in the storage unit 91 of the control unit 9.
After the shot image G1 is formed, the chuck table 30 holding the wafer W is moved by the cutting feed unit 11 shown in fig. 1, for example. That is, the chuck table 30 holding the wafer W is moved by a predetermined distance, for example, in the +x direction with respect to the macro imaging unit 51 in a stopped state. This moving distance of the chuck table 30 is, for example, the same value as the length in the X-axis direction of the photographing region 510 of the macro photographing unit 51 shown in fig. 2.
By moving the chuck table 30 as described above, the imaging region 510 of the macro imaging unit 51 is positioned aside in the X-axis direction of the imaging position when the imaging image G1 is imaged. Then, the front surface Wa of the wafer W is photographed by the macro photographing unit 51, and a photographed image G2 shown in fig. 4 is formed side by side with the photographed image G1 in the X-axis direction. The captured image G2 is stored in the storage unit 91 of the control unit 9.
For example, the control unit 9 shown in fig. 1 has a combined image forming section 92, and the combined image forming section 92 combines the photographed images formed by the macro photographing unit 51 to form a combined image. The combined image forming unit 92 displays, for example, a combined image GA shown in fig. 4, which is formed by combining the photographed image G1 stored in the storage unit 91 and the newly photographed image G2, on a virtual screen of a predetermined resolution.
Next, the pattern matching unit 93 included in the control unit 9 shown in fig. 1 performs pattern matching of whether or not the target image GT is present in the combined image GA. That is, the pattern matching unit 93 superimposes the target image GT on the combined image GA displayed on the virtual screen of the predetermined resolution, for example, and moves the target image GT in the X-axis direction or the Y-axis direction on the combined image GA by, for example, one pixel, thereby detecting a region having the highest correlation with the target image GT in the combined image GA as a region matching the target image GT.
As shown in fig. 4, the pattern matching unit 93 cannot detect a region matching the target image GT in the combined image GA, and thus further photographs the front surface Wa of the wafer W by the macro photographing unit 51. That is, the macro imaging unit 51 is moved by the index feed unit 12 shown in fig. 1 by a predetermined distance, for example, in the +y direction with respect to the chuck table 30 in a state where the movement is stopped. This moving distance of the macro photographing unit 51 is, for example, the same value as the length in the Y-axis direction of the photographing region 510 of the macro photographing unit 51.
By moving the macro imaging unit 51 as described above, the imaging region 510 of the macro imaging unit 51 is positioned aside in the Y-axis direction of the imaging position when the imaging image G2 is imaged. Then, the front surface Wa of the wafer W is photographed by the macro photographing unit 51, and a photographed image G3 shown in fig. 5 is formed side by side with the photographed image G2 in the Y-axis direction. The captured image G3 is stored in the storage unit 91 of the control unit 9.
The combined image forming unit 92 displays, on a virtual screen of a predetermined resolution, a combined image GB obtained by combining the combined image GA stored in the storage unit 91 and the newly captured image G3, in which the combined image GA is obtained by combining the captured image G1 and the captured image G2. Next, the pattern matching unit 93 superimposes the target image GT on the combined image GB, moves the target image GT in the X-axis direction or the Y-axis direction on the combined image GB by one pixel, and detects a region matching the target image GT in the combined image GB.
As shown in fig. 5, the pattern matching unit 93 cannot detect a region matching the target image GT in the combined image GB, and thus further photographs the front surface Wa of the wafer W by the macro photographing unit 51. That is, the macro imaging unit 51 that suctions and holds the chuck table 30 in a state where the movement is stopped is moved relatively in the-X direction by the same distance as the length of the imaging region 510 of the macro imaging unit 51 in the X-axis direction, for example, and the imaging region 510 is positioned aside in the X-axis direction from the imaging position at the time of imaging the imaging image G3. Then, the front surface Wa of the wafer W is photographed by the macro photographing unit 51, and a photographed image G4 shown in fig. 6, which is aligned with the photographed image G3 in the X-axis direction, is formed and stored in the storage 91.
As shown in fig. 4 to 6, the macro imaging unit 51 images the wafer W such that, for example, the imaging region 510 traces a clockwise spiral track on the wafer W when viewed from above.
As shown in fig. 6, the combined image forming unit 92 displays a combined image GC in which the combined image GB stored in the storage unit 91 and the newly captured image G4 are combined together on a virtual screen of a predetermined resolution. Next, the pattern matching unit 93 superimposes the target image GT on the combined image GC, moves the target image GT in the X-axis direction or the Y-axis direction on the combined image GC by one pixel, and detects a region matching the target image GT in the combined image GC to find the macro alignment mark MA.
As described above, the alignment method of the present invention performs the following confirmation process: at least two taken images of the wafer W newly held on the chuck table 30 by the macro imaging unit 51 are combined to form combined images GA to GC, and each time each combined image GA to GC is formed, pattern matching is performed in the combined images GA to GC to confirm the presence or absence of the target image GT, whereby the conventionally performed spiral search is not required when searching for the macro alignment mark MA of the new wafer W to be processed. That is, the imaging region 510 of the macro imaging unit 51 does not need to be moved in a spiral manner by repeating the number of pixels of the target image GT as in the conventional technique, and does not need to perform pattern matching of the target image GT for each of the imaged images captured by repeating the number of pixels. Therefore, the macro alignment mark MA can be found faster than before, and thus the alignment time can be shortened.
In the conventional spiral search, the macro imaging unit 51 forms an imaging image, matches a pattern using the imaging image and the target image GT, and when the target image GT cannot be detected in the imaging image, deletes the formed imaging image from the storage unit 91 and performs the next imaging. In contrast, in the alignment method of the present invention, the combined images GA to GC are formed, and therefore the capacity of the image data stored in the storage unit 91 increases. However, since the number of times the macro imaging unit 51 images the wafer W is greatly reduced as compared with the conventional technique, the operation load of the control unit 9 of the cutting device 1 is relatively reduced.
(3) Determination of segmentation predetermined lines
The macro alignment mark MA is found, for example, for two devices D located apart from each other in the X-axis direction. Next, the 1 st division scheduled line S1 and the 2 nd division scheduled line S2 are determined from the found macro alignment mark MA and micro alignment mark MB.
First, for example, rough θ alignment is performed to align the 1 st division line S1 of the wafer W substantially parallel to the X axis direction. Regarding the rough θ alignment, the chuck table 30 shown in fig. 1, which suctions and holds the wafer W, is angularly adjusted by the rotation unit 31 so that the Y-axis coordinate positions of the macro alignment marks MA of the two captured images for rough θ alignment (for example, the combined image G4 formed in the confirmation step) are substantially identical.
Further, after the chuck table 30 moves in the X-axis direction by the amount of the plurality of devices D, the macro imaging unit 51 performs imaging to form an imaged image for coarse θ alignment, which reflects the macro alignment mark MA of a certain device D. The chuck table 30 is angularly adjusted by the rotation means 31 so that a straight line connecting the macro alignment marks MA at positions separated in the X-axis direction is substantially parallel to the X-axis direction, thereby completing the rough θ alignment in which the 1 st division predetermined line S1 is substantially parallel to the X-axis direction, so that the Y-axis coordinate position of the macro alignment mark MA of the previously used rough θ alignment captured image is substantially coincident with the Y-axis coordinate position of the macro alignment mark MA of the later formed rough θ alignment captured image.
Next, the cutting device 1 shown in fig. 1 is in a state in which the wafer W can be imaged by the microscopic imaging means 52. In addition, one of the macro alignment marks MA (refer to fig. 6) found previously is positioned at the center of the photographing region of the micro photographing unit 52.
Under the control of the control unit 9, the chuck table 30 holding the wafer W by suction is moved by the cutting feed unit 11 by a distance Lx1 (distance Lx1 stored in the storage portion 91) between the macro alignment mark MA and the micro alignment mark MB in the X-axis direction shown in fig. 2, and the micro imaging unit 52 is moved by the index feed unit 12 by a distance Ly1 (distance Ly1 stored in the storage portion 91) between the macro alignment mark MA and the micro alignment mark MB in the Y-axis direction. Then, the front surface Wa of the wafer W is photographed by the microscopic photographing unit 52 to form a photographed image for high-precision θ alignment showing the microscopic alignment marks MB.
For example, the high-precision θ alignment is performed using a high-precision θ alignment captured image in which the microscopic alignment marks MB of the two devices D are displayed adjacent to one 1 st division line S1 and at positions separated from each other in the X-axis direction. Then, the chuck table 30 is angularly adjusted by the rotation unit 31 until the shift of the Y-axis coordinate position of each microscopic alignment mark MB of the two high-precision θ -alignment captured images is within the allowable value, thereby completing the θ -alignment with high precision.
Next, the chuck table 30 shown in fig. 1 is moved in the X-axis direction, for example, the center of the front face Wa of the wafer W is positioned at the imaging region of the microscopic imaging unit 52, a captured image is formed by the microscopic imaging unit 52, and the microscopic alignment mark MB in the captured image is recognized. Then, it is determined whether or not the shift of the Y-axis coordinate position of the microscopic alignment mark MB is within the allowable value, and in the case of being out of the allowable value, the microscopic photographing unit 52 is appropriately moved in the Y-axis direction by the index feeding unit 12 so that the shift of the Y-axis coordinate position of the microscopic alignment mark MB is within the allowable value.
After the shift of the Y-axis coordinate position of the microscopic alignment mark MB is within the allowable value, the index feeding unit 12 moves the microscopic photographing unit 52 in the Y-axis direction by the distance Ly2 from the microscopic alignment mark MB to the center line in the width direction of the 1 st division scheduled line S1 shown in fig. 2, thereby performing alignment of the reference line (reticle) of the microscopic photographing unit 52 with the reticle overlapping the 1 st division scheduled line S1. Then, the coordinate position of the reticle in the Y-axis direction when the reticle overlaps with the 1 st division scheduled line S1 is stored in the storage unit 91 of the control unit 9 as a position where the cutting unit 6 is positioned when the cutting tool 63 actually cuts the wafer W.
As described above, after the coordinate position in the Y-axis direction at the time of actually cutting the 1 st division scheduled line S1 is stored in the storage unit 91, the chuck table 30 is accurately rotated by 90 degrees by the rotation unit 31 to perform θ alignment with high accuracy for aligning the 2 nd division scheduled line S2 of the wafer W in parallel with the X-axis direction, and then the Y-axis coordinate position at which the cutting unit 6 is positioned at the time of actually cutting the 2 nd division scheduled line S2 is detected and stored in the storage unit 91 (reticle alignment is performed).
In this way, the cutting device 1 is in a state in which the 1 st division line S1 and the 2 nd division line S2 of the new wafer W are determined.
(4) Cutting of wafers
Next, the cutting device 1 shown in fig. 1 performs cutting processing on a new wafer W sucked and held by the chuck table 30. For example, first, the cutting unit 6 is positioned by the index feed unit 12 at the Y-axis coordinate position at which the 1 st division scheduled line S1 is actually cut, which is stored in the storage unit 91 of the control unit 9. Under the control of the control unit 9, the cutting unit 6 is lowered in the-Z direction by the cutting feed unit 16, and the cutting unit 6 is positioned at a predetermined cutting feed position. The cutting feed unit 11 performs cutting feed at a predetermined cutting feed speed with respect to the chuck table 30 holding the wafer W toward the cutting unit 6.
A motor, not shown, rotates the rotation shaft 60 of the cutting unit 6 at a high speed, and cuts the cutting tool 63 fixed to the rotation shaft 60 into the wafer W while rotating with the rotation of the rotation shaft 60, thereby cutting the 1 st division line S1.
When the chuck table 30 moves to a predetermined position in the X axis direction where the cutting tool 63 finishes cutting the 1 st division predetermined line S1, the plunge feeding unit 16 moves up the cutting unit 6 to separate the cutting tool 63 from the wafer W, and then the cutting feeding unit 11 returns the chuck table 30 to the cutting feed start position. The indexing feed unit 12 moves the cutting unit 6 in the Y-axis direction by a predetermined indexing feed amount, and thereby positions the cutting tool 63 on the 1 st division preset line S1 located beside the 1 st division preset line S1 which has been cut. Then, the cutting process is performed in the same manner as before. The same cutting is sequentially performed, and all the 1 st division lines S1 are cut.
After the chuck table 30 is rotated by 90 degrees, the 2 nd division line S2 is cut, and all the division lines of the wafer W are cut vertically and horizontally.
The steps of the alignment method of the present invention are not limited to the above-described embodiments, and may be implemented in various ways within the scope of the technical idea. The constituent elements of the cutting device 1 shown in the drawings are not limited to this, and may be appropriately changed within a range in which the effects of the present invention can be exhibited.
The alignment method of the present invention can be implemented in a laser processing apparatus that performs a desired process on a wafer W by laser irradiation.

Claims (1)

1. An alignment method for holding a wafer having a device formed in a region defined by a 1 st division scheduled line set on a front surface and a 2 nd division scheduled line intersecting the 1 st division scheduled line by a chuck table, photographing the wafer held by the chuck table by a photographing unit, detecting an alignment mark arranged in the region, thereby determining the 1 st division scheduled line and the 2 nd division scheduled line,
the alignment method comprises the following steps:
a registration step of registering a target image including an alignment mark in a region smaller than a photographing region of the photographing unit, the photographing region being smaller than the photographing region; and
a confirmation step of combining at least two side-by-side photographed images obtained by photographing a wafer newly held on the chuck table by the photographing means to form a combined image, wherein each time the combined image is formed, pattern matching is performed in the combined image to confirm the presence or absence of the target image,
if the target image is detected in the confirming step, the 1 st division scheduled line and the 2 nd division scheduled line are determined according to the alignment mark in the target image.
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Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2004279332A (en) * 2003-03-18 2004-10-07 Nikon Corp Method and instrument for measuring position, exposure method, and exposure device
CN102820239A (en) * 2011-06-10 2012-12-12 株式会社迪思科 Detection method for predetermined lines of division
CN102842494A (en) * 2011-06-23 2012-12-26 株式会社迪思科 Production method of wafer
CN105914174A (en) * 2015-02-25 2016-08-31 株式会社迪思科 Processing apparatus

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0742131U (en) * 1993-12-25 1995-07-21 ミツミ電機株式会社 Semiconductor wafer dicing position recognition method
JP2007088028A (en) 2005-09-20 2007-04-05 Disco Abrasive Syst Ltd Wafer separation equipment and alignment method of wafer
JP2008141018A (en) * 2006-12-01 2008-06-19 Canon Inc Exposure device, its program and device manufacturing method
JP2010010539A (en) 2008-06-30 2010-01-14 Disco Abrasive Syst Ltd Working device equipped with alignment means
JP6215730B2 (en) * 2014-02-26 2017-10-18 株式会社ディスコ Wafer center detection method in processing equipment
JP2016015438A (en) * 2014-07-03 2016-01-28 株式会社ディスコ Alignment method

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2004279332A (en) * 2003-03-18 2004-10-07 Nikon Corp Method and instrument for measuring position, exposure method, and exposure device
CN102820239A (en) * 2011-06-10 2012-12-12 株式会社迪思科 Detection method for predetermined lines of division
CN102842494A (en) * 2011-06-23 2012-12-26 株式会社迪思科 Production method of wafer
CN105914174A (en) * 2015-02-25 2016-08-31 株式会社迪思科 Processing apparatus

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