JP6955955B2 - Wafer processing method - Google Patents

Description

The present invention relates to a processing method for processing a wafer.

A cutting device that cuts a plate-shaped wafer with a cutting blade along a planned division line performs alignment to recognize the planned division line in which the cutting blade is cut after the wafer is transferred to the holding table (for example). See Patent Document 1).

When starting the cutting process, the operator (operator) sets the processing conditions (device data) for setting the cutting feed speed, depth of cut, index feed amount, target pattern used at the time of alignment, etc. required for the cutting process. The operator selects it from the machining condition list (device data list) that is input or input to the cutting device in advance and is listed.

On the other hand, when starting the cutting process, the cutting device is provided with a two-dimensional code by arranging a two-dimensional code on the cassette containing the wafer or the ring frame supporting the wafer, instead of having the operator input or select the processing conditions. There is a method of having a reading unit read the two-dimensional code to select processing conditions (see, for example, Patent Document 2).

Japanese Unexamined Patent Publication No. 07-106405 Japanese Unexamined Patent Publication No. 09-303873

When the operator selects a machining condition from the machining condition list, the machining condition may be selected incorrectly, and the machining condition corresponding to the wafer held by the holding table is not selected. Therefore, for example, the index feed amount is appropriate. An alignment error may occur due to the difference from the above value, and the fully automatic operation of the cutting device may be interrupted. In this case, it is necessary for the operator to reselect the correct machining conditions and then start the fully automatic operation of the cutting device.
When the two-dimensional code is read by the cutting device, a problem occurs when the two-dimensional code is not arranged on the cassette or the ring frame.

Therefore, when machining a wafer (for example, cutting or laser machining), the operator does not have to select machining conditions, and a two-dimensional code is arranged on a cassette, a ring frame, or the like. There is a problem that the processing conditions are selected at least.

The present invention for solving the above problems is a wafer using a processing apparatus that holds a wafer in which a device is formed in a region partitioned by a planned division line on a holding table and processes the wafer along the planned division line. It is a processing method, and the processing apparatus includes a low-magnification imaging means and a high-magnification imaging means, and from a holding step of holding a wafer on the holding table and a processing condition list listing the plurality of processing conditions. Whether the selection step of selecting one processing condition, the storage macro image stored in the processing condition selected in the selection step, and the first image captured by the low-magnification imaging means are compared, and both images match. A first determination step of determining whether or not, and a first repetitive step of returning to the selection step when it is determined in the first determination step that the stored macro image and the first image do not match, and the said. When it is determined in the first determination step that the storage macro image and the first image match, the storage microimage stored in the processing conditions used in the first determination step and the high-magnification imaging means. The storage micro image and the second image do not match in the second determination step of comparing with the second image captured by the image and determining whether or not both images match, and in the second determination step. When it was determined that the memory micro image and the second image matched in the second repeating step of returning to the selection step and the second determination step, it was used in the second determination step. This is a wafer processing method including a processing step of processing a wafer under processing conditions in which the storage microimage is stored.

The wafer processing method according to the present invention is carried out using a processing apparatus including a low-magnification imaging means and a high-magnification imaging means, and a holding step of holding the wafer on a holding table and a plurality of processing conditions are listed. The selection process of selecting one processing condition from the processing condition list is compared with the storage macro image stored in the processing condition selected in the selection process and the first image captured by the low-magnification imaging means, and both images match. The first determination step of determining whether or not, and the first iterative process of returning to the selection process when it is determined in the first determination step that the stored macro image and the first image do not match, and the first determination. When it is determined in the process that the storage macro image and the first image match, the storage micro image stored in the processing conditions used in the first determination step and the second image captured by the high-magnification imaging means are combined. When it is determined in the second determination step of comparing and determining whether or not the two images match, and the storage micro image and the second image do not match in the second determination step, the process returns to the selection process. The process and the processing step of processing the wafer under the processing conditions in which the stored micro image used in the second determination step is stored when it is determined that the stored micro image and the second image match in the second determination process. Therefore, it is not necessary for the operator to select the machining conditions, and the machining conditions can be selected even if the two-dimensional code is not arranged on the ring frame or the like.

It is a perspective view which shows an example of a processing apparatus. This is an example of a machining condition list that lists a plurality of machining conditions. It is a top view which shows an example of the structure of the surface of a wafer. FIG. 4A is an example of a storage macro image. FIG. 4B is another example of the storage macro image. FIG. 5A is an example of a memory micro image. FIG. 5B is another example of the memory microimage. It is a flowchart explaining the flow of each process of the wafer processing method. FIG. 5 is a cross-sectional view showing a state in which the holding table is positioned at a predetermined coordinate position on the X-axis and Y-axis planes so that the center of the holding surface of the holding table is located directly below the imaging unit. It is explanatory drawing explaining the judgment of the 1st judgment part in the 1st 1st judgment step. It is explanatory drawing explaining the judgment of the 1st judgment part in the 1st judgment process of the 2nd time (the 3rd time). It is explanatory drawing explaining the judgment of the 2nd judgment part in the 1st 2nd judgment process. It is explanatory drawing explaining the judgment of the 2nd judgment part in the 2nd 2nd judgment step.

In the processing apparatus 1 shown in FIG. 1 used for carrying out the wafer processing method according to the present invention, the wafer W held on the holding table 30 is subjected to the first processing means 61 and the first processing means 61 provided with a rotating cutting blade 613. It is a device that cuts by the processing means 62 of 2. The processing apparatus used to carry out the wafer processing method according to the present invention is not limited to a cutting apparatus such as the processing apparatus 1, and the wafer is modified by irradiating the wafer with a laser having a predetermined wavelength. It may be a laser processing apparatus that forms a layer or cuts a wafer.

On the base 10 of the processing apparatus 1, a processing feed means 13 for relatively moving the first processing means 61 and the holding table 30 in the X-axis direction of the processing feed direction is arranged. The machining feed means 13 includes a ball screw 130 having an axial center in the X-axis direction, a pair of guide rails 131 arranged in parallel with the ball screw 130, a motor 132 for rotating the ball screw 130, and a ball screw 130 having an internal nut. It is composed of a movable plate 133 that is screwed into a screw and whose bottom is in sliding contact with the guide rail 131. Then, when the motor 132 rotates the ball screw 130, the movable plate 133 is guided by the guide rail 131 and moves in the X-axis direction, and the holding table 30 arranged on the movable plate 133 is moved by the movable plate 133. Moves in the X-axis direction with the movement of.

The holding table 30 for holding the wafer W has, for example, a circular plate-like outer shape, and includes a suction portion 300 made of a porous member that sucks the wafer W, and a frame body 301 that supports the suction portion 300. The wafer W is sucked and held on the holding surface 300a which is the exposed surface of the suction portion 300 and is flush with the frame body 301. The holding table 30 can be rotated around the axis in the Z-axis direction by the rotating means 32 arranged on the bottom surface side of the holding table 30, and the rotation center of the holding table 30 and the center of the holding surface 300a coincide with each other. There is. Around the holding table 30, four fixed clamps 34 that sandwich and fix the annular frame F that supports the wafer W are evenly arranged in the circumferential direction.

On the rear side of the base 10, a gantry column 14 is erected so as to straddle the movement path of the holding table 30. On the front surface of the portal column 14, a first index feeding means 15 for reciprocating the first machining means 61 in the Y-axis direction orthogonal to the X-axis direction and the Z-axis direction, and a second machining means 62 are provided. A second index feeding means 16 that reciprocates in the Y-axis direction is provided.

The first index feeding means 15 is connected to, for example, a ball screw 150 having an axial center in the Y-axis direction, a pair of guide rails 151 arranged in parallel with the ball screw 150, and one end of the ball screw 150 on the + Y direction side. A motor (not shown) and a movable plate 153 in which an internal nut is screwed into a ball screw 150 and a side portion is in sliding contact with a guide rail 151 are provided. Then, when a motor (not shown) rotates the ball screw 150, the movable plate 153 is guided by the guide rail 151 and moves in the Y-axis direction, and is moved on the movable plate 153 via the first cutting feed means 17. The arranged first processing means 61 is indexed in the Y-axis direction.

The first cutting feed means 17 can move the first processing means 61 in the Z-axis direction orthogonal to the holding surface 300a of the holding table 30, and has a ball screw 170 having an axial center in the Z-axis direction. A pair of guide rails 171 arranged in parallel with the ball screw 170, a motor 172 connected to the ball screw 170, and a first processing means 61 are supported, an internal nut is screwed into the ball screw 170, and the side portion is a guide rail. It is provided with a support member 173 that is in sliding contact with 171. When the motor 172 rotates the ball screw 170, the support member 173 is guided by the pair of guide rails 171 and moves in the Z-axis direction, and the first processing means 61 moves in the Z-axis direction accordingly.

The first processing means 61 includes a spindle 610 whose axial direction is the Y-axis direction, a housing 611 fixed to the lower end side of the support member 173 to rotatably support the spindle 610, and a motor (not shown) for rotating the spindle 610. A cutting blade 613 having an annular outer shape attached to the tip of the spindle 610 is provided, and the cutting blade 613 rotates as the motor rotationally drives the spindle 610.

The second index feeding means 16 includes, for example, a ball screw 160 having an axial center in the Y-axis direction, a pair of guide rails 151 arranged in parallel with the ball screw 160, a motor 162 connected to the ball screw 160, and the inside. The nut is screwed into the ball screw 160, and the side portion is provided with a movable plate 163 that is in sliding contact with the guide rail 161. When the motor 162 rotates the ball screw 160, the movable plate 163 is guided by the guide rail 151 and moves in the Y-axis direction, and is arranged on the movable plate 163 via the second cutting feed means 18. The second processing means 62 is indexed in the Y-axis direction.

The second notch feeding means 18 includes a ball screw 180 having an axial center in the Z-axis direction, a pair of guide rails 181 arranged in parallel with the ball screw 180, a motor 182 connected to the ball screw 180, and a second. It is provided with a support member 183 that supports the processing means 62, has an internal nut screwed into the ball screw 180, and has a side portion that is in sliding contact with the guide rail 181. When the motor 182 rotates the ball screw 180, the support member 183 is guided by the pair of guide rails 181 and moves in the Z-axis direction, and the second processing means 62 moves in the Z-axis direction accordingly.

The second processing means 62 is arranged so as to face the first processing means 61 in the Y-axis direction. Since the first processing means 61 and the second processing means 62 are configured in the same manner, the description of the second processing means 62 will be omitted.

An imaging unit 20 for imaging the wafer W is arranged on the side surface of the housing 611 of the first processing means 61. The image pickup unit 20 includes an image pickup element (not shown), an objective lens 200 whose magnification is variable between low magnification and high magnification by a magnification adjustment means, and a low magnification image pickup means 201 that performs imaging with an objective lens 200 set to a low magnification. A high-magnification imaging means 202 that performs imaging with an objective lens 200 set to a high magnification, and an illuminating means 203 that irradiates the wafer W sucked and held on the holding table 30 with light, and low-magnification imaging. The wafer W can be imaged from above by switching between the means 201 and the high-magnification imaging means 202. The image pickup unit 20 and the first processing means 61 are integrally formed, and both move in the Y-axis direction and the Z-axis direction in conjunction with each other. The image pickup unit 20 is also arranged on the side surface of the housing of the second processing means 62.

The processing apparatus 1 includes, for example, a control means 9 that controls the entire apparatus. The control means 9 is connected to the machining feed means 13, the first index feed means 15, the first notch feed means 17, the rotation means 32, etc. by wiring (not shown), and is under the control of the control means 9. , The movement operation of the holding table 30 by the machining feed means 13 in the X-axis direction, the index feed operation of the first machining means 61 in the Y-axis direction by the first index feed means 15, and the first by the first cut feed means 17. The cutting feed operation of the processing means 61 in the Z-axis direction, the rotation operation of the holding table 30 by the rotating means 32, and the like are controlled.

The control means 9 includes a storage unit 90 composed of a storage element such as a memory, and the storage unit 90 stores the processing condition list (device data list) K shown in FIG. The processing condition list K is a list of a plurality of processing conditions corresponding to each type of wafer to be processed, and each processing condition includes, for example, processing condition No. Can be identified by the processing condition ID. For example, No. 1 shown in the processing condition list K. As for the processing condition of 001, the processing condition ID is MM-SAMPLE, and No. As for the processing condition of 002, the processing condition ID is INCH-SAMPLE.

The processing conditions are data in which various settings for performing appropriate cutting processing on the wafer for each type of wafer to be processed are collectively stored, and the various settings are the processing feed means 13 shown in FIG. The machining feed rate of the holding table 30 holding the wafer according to the above, the index feed amount of the first machining means 61 by the first index feed means 15, and the cut feed height of the first machining means 61 by the first cut feed means 17. The position, the rotation speed of the spindle 610 of the first processing means 61, the imaging coordinate position on the X-axis Y-axis plane in which the wafer sucked and held by the imaging unit 20 on the holding table 30 is imaged, the storage macro image described later, and These are memory microimages and the like, which will be described later.
The image pickup coordinate position of the wafer by the image pickup unit 20 is determined based on, for example, the center of the holding surface 300a of the holding table 30 that can be constantly grasped by the processing device 1, and the wafer to be processed under the selected processing conditions. If the processing conditions correspond to the above, the image obtained by imaging the wafer at the imaging coordinate position and the storage macro image will match.
The index feed amount of the first processing means 61 by the first index feed means 15 is, for example, an amount by which the first index feed means 15 moves the first processing means 61 in the Y-axis direction by one index. Yes, 1 index is the distance from the center line in the width direction of a certain scheduled division line S shown in FIG. 3 to the center line of the scheduled division line S located next to the center line.

The wafer W shown in FIG. 1 is, for example, a circular plate-shaped silicon semiconductor wafer, and devices D are formed on the surface Wa of the wafer W in a grid-like region partitioned by a planned division line S. A dicing tape T having a diameter larger than that of the wafer W is attached to the back surface Wb of the wafer W. An annular frame F having a circular opening is attached to the outer peripheral region of the adhesive surface of the dicing tape T, and the wafer W is supported by the annular frame F via the dicing tape T and handled via the annular frame F. Is ready for. Each scheduled division line S extending in the same direction (for example, the X-axis direction in FIGS. 1 and 3) on the surface Wa of the wafer W is defined as the planned division line S of the first channel, while on the surface Wa of the wafer W. Each scheduled division line S extending in a direction orthogonal to the planned division line S of the first channel (Y-axis direction in FIGS. 1 and 3) is referred to as a scheduled division line S of the second channel.

As shown in FIG. 3, the same circuit pattern is formed on the surface of each device D of the wafer W. Then, one pattern having a characteristic shape among the circuit patterns is selected in advance as the macro target PA, and an image including the macro target PA (an image captured at a low magnification) is shown in FIG. 4 (A). It becomes the storage macro image G1 shown. The macro target PA is formed at the same position for each of the plurality of devices D, for example, at a corner portion (left corner) of the device D.
The storage macro image may include a pattern having a simple shape such as a circular macro target PA, such as the storage macro image G1.

A part of the characteristics of the elements and wiring formed on the surface of the device D shown enlarged in FIG. 3 (inside the rectangular frame shown by the dotted line) is selected in advance as the micro target PC, and includes this micro target PC. The image (image captured at high magnification) is the storage micro image G3 shown in FIG. 5 (A). The size of the micro-target PC is smaller than the size of the macro-target PA. Further, it is preferable that the storage microimage includes a straight line extending in the Y-axis direction and a straight line extending in the X-axis direction in the image, as in the storage microimage G3.

In the present embodiment, for example, No. 1 shown in the processing condition list K shown in FIG. The storage macro image G1 shown in FIG. 4 (A) and the storage micro image G3 shown in FIG. 5 (A) are stored in the processing condition AAAA-SAMPLE of 003. Further, the information of the distance Lx3 between the macro target PA and the micro target PC in the X-axis direction and the information of the distance Ly3 between the macro target PA and the micro target PC in the Y-axis direction shown in FIG. 3 are also stored in the processing condition AAAAA-SAMPLE. ing.
For example, No. 1 shown in the processing condition list K shown in FIG. The processing conditions MM-SAMPLE of 001 include a storage macro image G2 including a rectangular macro target PB shown in FIG. 4 (B) formed on a device of a wafer of a different type from the wafer W, and FIG. 5 (B). It is assumed that the storage micro image G3 shown in the above is stored.
For example, No. 1 shown in the processing condition list K shown in FIG. The processing condition INCH-SAMPLE of 002 includes a storage macro image G1 shown in FIG. 4 (A) and a memory including a micro target PD shown in FIG. 5 (B) formed on a device of a wafer of a different type from the wafer W. The micro image G4 is stored. Further, information on the distance between the macro target PA shown in FIG. 4 (A) and the micro target PD shown in FIG. 5 (B) on a different type of wafer from the wafer W in the X-axis direction, and the macro target PA and the micro target PD Information on the distance in the Y-axis direction is also stored in the processing condition INCH-SAMPLE.

Hereinafter, each step of the processing method according to the present invention when the wafer W shown in FIGS. 1 and 3 is cut along the scheduled division line S by using the processing apparatus 1 shown in FIG. 1 will be described. Each step of the processing method according to the present invention is carried out in the order shown in the flowchart shown in FIG.

(1) Holding Step In the first holding step, the wafer W supported by the annular frame F via the dicing tape T shown in FIG. 1 has the dicing tape T side facing downward and the holding surface 300a. The wafer W is placed on the holding surface 300a of the holding table 30 so that the center and the center of the wafer W are aligned with each other. Then, the annular frame F is fixed by the fixed clamp 34 arranged around the holding table 30, and a suction source (not shown) connected to the holding table 30 operates to obtain a wafer on the holding surface 300a of the holding table 30. W is sucked and held.

(2-1) First Selection Step The control means 9 includes a machining condition selection unit 91 that selects one machining condition from the machining condition list K shown in FIG. 2, and the main selection step is performed by the machining condition selection unit 91. Is carried out. The machining condition selection unit 91 is, for example, the machining condition No. 1 shown in the machining condition list K. Select in order from the processing conditions with the youngest number. Therefore, the machining condition No. shown in the machining condition list K shown in FIG. 2 is shown. The machining condition MM-SAMPLE of 001 is first selected by the machining condition selection unit 91.

(3-1) First First Imaging Step Next, the holding table 30 that sucks and holds the wafer W shown in FIG. 1 is moved in the X-axis direction by the machining feed means 13. Further, the image pickup unit 20 is moved in the Y-axis direction by the first index feeding means 15. Then, under the control of the processing feed means 13 and the first index feed means 15 by the control means 9, the center of the holding surface 300a of the holding table 30 is directly below the objective lens 200 of the imaging unit 20 as shown in FIG. The holding table 30 is positioned at a predetermined coordinate position on the X-axis and Y-axis planes so as to be located at. The positioning of the holding table 30 based on the control of the machining feed means 13 and the first index feed means 15 by the control means 9 is based on the machining condition No. It is based on the processing condition MM-SAMPLE of 001.

By setting the magnification of the objective lens 200 to a low magnification and setting the set light amount of the illumination means 203 to a light amount suitable for low-magnification imaging, the low-magnification imaging means 201 can image the surface Wa of the wafer W. It will be possible. Then, at the X-axis and Y-axis coordinate positions with respect to the center of the holding surface 300a of the holding table 30, the substantially central region of the surface Wa of the wafer W is imaged by the low-magnification imaging means 201, and the first position having a relatively wide field of view is obtained. Image is formed.

In principle, in the holding step carried out earlier, the wafer W is sucked and held by the holding table 30 so that the center of the holding surface 300a of the holding table 30 and the center of the wafer W match. However, for example, the center of the wafer W on the holding table 30 and the center of the holding surface 300a may be misaligned due to, for example, a transfer deviation when the wafer W is conveyed to the holding table 30. When there is a deviation between the center of the holding surface 300a of the holding table 30 and the center of the surface Wa of the wafer W, the temporarily selected machining conditions are appropriate machining conditions corresponding to the wafer W to be machined. Even so, there is a possibility that the macro target is not included in the imaging region of the low-magnification imaging means 201, and it is determined that the stored macro image and the first image do not match in the first determination step described later. There is.

Therefore, the surface Wa of the wafer W is imaged by the low-magnification imaging means 201 at a plurality of imaging positions other than the imaging position with reference to the center of the holding surface 300a of the holding table 30, and the plurality of first images are further formed. It is formed. That is, for example, the first index feeding means 15 moves the imaging unit 20 in the Y-axis direction, and the rotating means 32 (not shown in FIG. 7) rotates the holding table 30 at a predetermined rotation speed. The low-magnification imaging means 201 moves with respect to the wafer W so as to draw a spiral locus from the center of the holding surface 300a toward the outside. Then, the low-magnification imaging means 201 that moves so as to draw a spiral locus images the surface Wa of the wafer W every unit time, so that the imaging can be performed at a plurality of imaging positions near the central region of the surface Wa of the wafer W. Each is performed, and a plurality of first images are formed. The imaging is performed while the first index feeding means 15 moves the imaging unit 20 in the Y-axis direction by one index.

(4-1) First First Judgment Step Information about each first image captured by the low-magnification imaging means 201 is transmitted from the imaging unit 20 to the first determination unit 92 of the control means 9. .. Each first image may be binarized, for example, to emphasize the edges. As shown in FIG. 8, the first determination unit 92 is a plurality of first images captured by the storage macro image G2 set in the processing condition MM-SAMPLE selected in the first selection step and the low-magnification imaging means 201. The images are compared one by one to determine whether or not they match.

In the present embodiment, since the storage macro image G2 stored in the processing condition MM-SAMPLE does not match each of the first images, the first determination unit 92 determines that they do not match. The process proceeds to the first iterative process shown in the flowchart of 6.

(5-1) First Repeating Step In the first judgment step, the first judgment unit 92 determines that the storage macro image G2 of the processing condition MM-SAMPLE and the first image do not match. According to the program configured based on the flowchart of FIG. 6, the second selection step described later is carried out in the processing apparatus 1.

(2-2) Second selection step In the second selection step, the machining condition No. 1 shown in the machining condition list K shown in FIG. 2 is shown. The machining condition INCH-SAMPLE of 002 is selected by the machining condition selection unit 91.

(3-2) Second First Imaging Step Next, the processing condition No. Based on the machining condition INCH-SAMPLE of 002, under the control of the machining feed means 13 and the first index feed means 15 by the control means 9, the center of the holding surface 300a of the holding table 30 is the objective lens 200 of the imaging unit 20. The holding table 30 is positioned at a predetermined coordinate position so as to be located directly below. Then, as shown in FIG. 7, at the X-axis Y-axis coordinate position with respect to the center of the holding surface 300a of the holding table 30, the substantially central region of the surface Wa of the wafer W is imaged by the low-magnification imaging means 201, and the second image is taken. The image of 1 is formed.

Further, the first index feeding means 15 moves the imaging unit 20 in the Y-axis direction, and the rotating means 32 rotates the holding table 30 at a predetermined rotation speed. Then, the low-magnification imaging means 201 that moves so as to draw a spiral locus with respect to the surface Wa of the wafer W performs imaging at a plurality of imaging positions near the central region of the surface Wa of the wafer W, and the first image is obtained. Are formed in plurality.

(4-2) Second First Judgment Step Information about each first image captured by the low-magnification imaging means 201 is transmitted from the imaging unit 20 to the first determination unit 92 of the control means 9. .. As shown in FIG. 9, the first determination unit 92 captures the storage macro image G1 set in the processing condition INCH-SAMPLE selected in the second selection step and the first image captured by the low-magnification imaging means 201. For example, it is determined that one matches.

After the first determination unit 92 determines that the storage macro image G1 and the first image match in the second first determination step as described above, for example, the first of the wafer W shown in FIGS. 1 and 3. Coarse θ alignment is performed so that the scheduled division line S of one channel is aligned substantially parallel to the X-axis direction. Coarse θ alignment is performed, for example, by two positions adjacent to one scheduled division line S (scheduled division line S extending in the X-axis direction) of the first channel shown in FIGS. 1 and 3 and separated from each other in the X-axis direction. This is performed using an captured image in which each macro target PA of the device D is captured. That is, the low-magnification imaging means 201 forms an image for coarse θ matching in which the macro target PA of the device D is captured, and after the holding table 30 is moved in the X-axis direction by one device D, the low magnification is obtained. Imaging is performed by the imaging means 201, and another captured image for coarse θ matching in which the macro target PA is captured is formed.
Then, the holding table 30 is rotated by a predetermined angle by the rotating means 32 so that the Y-axis coordinate positions of the macro target PAs of the two captured images for coarse θ matching are approximately the same.

Further, after the holding table 30 is moved by several devices D in the X-axis direction, imaging is performed by the low-magnification imaging means 201, and an image for coarse θ matching in which the macro target PA of a device D is captured is obtained. It is formed. Hold so that the Y-axis coordinate position of the macro target PA of the captured image for coarse θ alignment used earlier and the Y-axis coordinate position of the macro target PA of the captured image for coarse θ alignment further formed are approximately the same. The table 30 is rotated by the rotating means 32 by a predetermined angle, the straight line connecting the macro target PAs located at positions distant from the X-axis direction is substantially parallel to the X-axis direction, and the planned division line S of the first channel is defined as the X-axis direction. Coarse θ alignment that makes them almost parallel is completed. After that, according to the program configured based on the flowchart of FIG. 6, the first second imaging step described later is carried out in the processing apparatus 1.

(6-1) First Second Imaging Step The magnification of the objective lens 200 shown in FIG. 1 is switched to a high magnification, and the set light amount of the illumination means 203 is set to a light amount suitable for high-magnification imaging. As a result, the wafer W can be imaged by the high-magnification imaging means 202. Further, one of the previously detected macro target PAs is located in the center of the imaging area of the high-magnification imaging means 202.

Next, the condition No. Based on the setting stored in the machining condition INCH-SAMPLE of 002, the holding table 30 that sucks and holds the wafer W shown in FIG. The image pickup unit 20 is moved by the distance in the X-axis direction, and the image pickup unit 20 is moved by the first index feeding means 15 by the distance in the Y-axis direction between the macro target PA and the micro target PD. After that, the surface Wa of the wafer W is imaged by the high-magnification imaging means 202 to form a second image having a relatively narrow field of view.

(7-1) First Second Judgment Step Information about the second image captured by the high-magnification imaging means 202 is transmitted from the imaging unit 20 to the second determination unit 93 of the control means 9 shown in FIG. Will be sent. As shown in FIG. 10, the second determination unit 93 includes the storage micro image G4 set in the processing condition INCH-SAMPLE selected in the second selection step and the second image captured by the high-magnification imaging means 202. To determine if they match.

In the present embodiment, since the storage microimage G4 stored in the processing condition INCH-SAMPLE and the second image do not match, the second determination unit 93 determines that they do not match, and FIG. The process proceeds to the second iterative process shown in the flowchart.

(8) Second Repeating Step In the second determination step, the second determination unit 93 determines that the storage microimage G4 of the processing condition INCH-SAMPLE and the second image do not match, and thus FIG. According to the program configured based on the flowchart of the above, the third selection step described later is carried out in the processing apparatus 1.

(2-3) Third selection step In the third selection step, the machining condition No. 1 shown in the machining condition list K shown in FIG. 2 is shown. The machining condition AAAA-SAMPLE of 003 is selected by the machining condition selection unit 91.

(3-3) Third First Imaging Step Next, the processing condition No. Based on the settings stored in the machining conditions AAAA-SAMPLE of 003, the holding surface 300a of the holding table 30 is controlled by the machining feeding means 13 and the first index feeding means 15 by the control means 9 shown in FIG. The holding table 30 and the image pickup unit 20 move so that the center of the image pickup unit 20 is located directly below the objective lens 200 of the image pickup unit 20. Then, as shown in FIG. 7, the substantially central region of the surface Wa of the wafer W is imaged by the low-magnification imaging means 201 at the X-axis and Y-axis coordinate positions with respect to the center of the holding surface 300a of the holding table 30. A first image is formed.

Further, the first index feeding means 15 moves the imaging unit 20 in the Y-axis direction, and the rotating means 32 rotates the holding table 30 at a predetermined rotation speed. Then, the low-magnification imaging means 201 that moves so as to draw a spiral locus with respect to the surface Wa of the wafer W performs imaging at a plurality of imaging positions near the central region of the surface Wa of the wafer W, and the first image is obtained. Are formed in plurality.

(4-3) Third First Judgment Step Information about each first image captured by the low-magnification imaging means 201 is transmitted from the imaging unit 20 to the first determination unit 92 of the control means 9 shown in FIG. Will be sent to. As shown in FIG. 9, the first determination unit 92 is a storage macro image G1 set in the processing condition AAAA-SAMPLE selected in the third selection step and the first image captured by the low-magnification imaging means 201. For example, it is determined that one matches.

After the first determination unit 92 determines that the storage macro image G1 and the first image match in the first determination step of the third time as described above, for example, the first of the wafer W shown in FIGS. Coarse θ alignment is performed so that the scheduled division line S of one channel is aligned substantially parallel to the X-axis direction. Then, after the coarse θ alignment of the scheduled division line S of the first channel is completed, the second second imaging step described later is carried out in the processing apparatus 1 according to the program configured based on the flowchart of FIG. ..

(6-2) Second Second Imaging Step The magnification of the objective lens 200 is switched to a high magnification, and the set light amount of the illumination means 203 is set to a light amount suitable for high-magnification imaging. The wafer W can be imaged by the magnification imaging means 202. Further, one of the previously detected macro target PAs is located in the center of the imaging area of the high-magnification imaging means 202.

Next, the condition No. Based on the machining condition AAAA-SAMPLE of 003, the holding table 30 that sucks and holds the wafer W is moved by the machining feed means 13 by the distance Lx3 in the X-axis direction between the macro target PA and the micro target PC shown in FIG. Further, the image pickup unit 20 is moved by the first index feeding means 15 by the distance Ly3 in the Y-axis direction between the macro target PA and the micro target PC. After that, the surface Wa of the wafer W is imaged by the high-magnification imaging means 202 to form a second image.

(7-2) Second Second Judgment Step Information about the second image captured by the high-magnification imaging means 202 is transmitted to the second determination unit 93 of the control means 9 shown in FIG. As shown in FIG. 11, the second determination unit 93 compares the storage microimage G3 set in the processing condition AAAA-SAMPLE with the second image captured by the high-magnification imaging means 202, and determines that they match.

After the second determination unit 93 determines that the storage micro image G3 and the second image match in the second second determination step as described above, for example, the first wafer W shown in FIGS. Highly accurate θ alignment is performed so that the scheduled division line S of one channel is aligned parallel to the X-axis direction. The highly accurate θ alignment is, for example, adjacent to one scheduled division line S (scheduled division line S extending in the X-axis direction) of the first channel shown in FIGS. 1 and 3 and located at a position separated from each other in the X-axis direction. This is done using captured images of each microtarget PC of the two devices D. That is, after the high-magnification imaging means 202 forms a highly accurate captured image for θ alignment in which the micro-target PC of the device D is captured, and the holding table 30 is moved in the X-axis direction by several devices D. The image is taken by the high-magnification imaging means 202, and another image captured by the micro-target PC of a device D for high-precision θ matching is formed.

Then, the holding table 30 is rotated by a predetermined angle by the rotating means 32 until the deviation of the Y-axis coordinate position of each of the two captured images is within the allowable value, and highly accurate θ alignment is completed.

Further, the holding table 30 moves in the X-axis direction, the center of the surface Wa of the wafer W is positioned in the imaging area of the high-magnification imaging means 202, the captured image is formed by the high-magnification imaging means 202, and the captured image is formed. The micro-target PC inside is recognized. Then, it is determined whether or not the deviation of the Y-axis coordinate position of the micro-target PC is within the permissible value, and if it is outside the permissible value, the deviation of the Y-axis coordinate position of the micro-target PC reaches within the permissible value. As described above, the imaging unit 20 is appropriately moved in the Y-axis direction by the first index feeding means 15.

After the deviation of the Y-axis coordinate position of the micro-target PC reaches within the permissible value, the first index feeding means 15 sets the image pickup unit 20 by the distance from the micro-target PC to the center line in the width direction of the planned division line S. By moving the image unit 20 in the Y-axis direction, the hairline alignment is performed so that the reference line (hairline) of the imaging unit 20 overlaps the scheduled division line S. Then, the coordinate position in the Y-axis direction when the hairline is overlapped with the scheduled division line S is the position of the control means 9 where the first processing means 61 is positioned when the cutting blade 613 actually cuts the wafer W. It is stored in the storage unit 90.

As described above, after the coordinate position in the Y-axis direction when actually cutting the planned division line S of the first channel is stored, the holding table 30 is accurately rotated by the rotating means 32 by 90 degrees, and the wafer W is Highly accurate θ alignment is performed to align the planned division line S of the second channel in parallel with the X-axis direction, and then when the planned division line S of the second channel is actually cut, the first processing means 61 is used. The Y-axis coordinate position to be positioned is detected and stored in the storage unit 90.

(9) Machining Step Next, the cutting apparatus 1 shown in FIG. 1 machins the wafer W under the machining conditions AAAAA-SAMPLE. For example, first, the first processing means 61 sets the first index feeding means 15 at the Y-axis coordinate position when the planned division line S of the first channel stored in the storage unit 90 of the control means 9 is actually cut. Positioned by. Further, the first cutting feed means 17 lowers the first machining means 61 in the −Z direction, and the first machining means 61 is positioned at the cutting feed position set in the machining condition AAAAA-SAMPLE. Further, the machining feed means 13 feeds the holding table 30 that holds the wafer W at the machining feed rate set in the machining conditions AAAAA-SAMPLE.

Then, a motor (not shown) rotates the spindle 610 of the first machining means 61 at the rotation speed set in the machining condition AAAA-SAMPLE, so that the cutting blade 613 fixed to the spindle 610 rotates the spindle 610. Along with this, the wafer W is cut while rotating, and the planned division line S is cut.

When the holding table 30 advances to a predetermined position in the X-axis direction in which the cutting blade 613 finishes cutting the scheduled division line S, the first cutting feed means 17 raises the first processing means 61 to wafer the cutting blade 613. It is separated from W, and then the machining feed means 13 returns the holding table 30 to the machining feed start position. Then, the first index feed means 15 moves the first machining means 61 in the Y-axis direction by the index feed amount set in the machining condition AAAAA-SAMPLE, so that the first index feed means 61 is next to the cut scheduled division line S. The cutting blade 613 is positioned with respect to the scheduled division line S located at. Then, the cutting process is carried out in the same manner as before. Hereinafter, by sequentially performing the same cutting, all the scheduled division lines S of the first channel are cut.
Further, by rotating the holding table 30 by 90 degrees and then cutting each scheduled division line S of the second channel, all the scheduled division lines S of the wafer W are cut vertically and horizontally.

As described above, the wafer processing method according to the present invention includes a holding step of holding the wafer W on the holding table 30 and a selection step of selecting one processing condition from the processing condition list K listing a plurality of processing conditions. And the first determination step of comparing the storage macro image stored in the processing conditions selected in the selection step with the first image captured by the low-magnification imaging means 201 and determining whether or not both images match. , When it is determined in the first determination step that the stored macro image and the first image do not match, the first repeating step of returning to the selection step and the stored macro image and the first image in the first determination step are When it is determined that they match, the storage micro image stored in the processing conditions used in the first determination step is compared with the second image captured by the high-magnification imaging means 202, and whether or not both images match is determined. When it is determined in the second determination step to determine and the storage micro image and the second image do not match in the second determination step, the process returns to the selection process. When it is determined that the image and the second image match, the memory used in the second determination step is stored. Since the processing process for processing the wafer W is provided under the processing conditions for storing the micro image, the processing conditions by the operator are provided. It becomes unnecessary to select the processing conditions, and the processing conditions can be selected even if the two-dimensional code is not arranged on the ring frame or the like.

W: Wafer Wa: Wafer front surface Wb: Wafer back surface S: Scheduled division line D: Device T: Dicing tape F: Circular frame 1: Processing device 10: Base 14: Gate column 30: Holding table 300: Adsorption part 300a: Holding surface 301: Frame 32: Rotating means 34: Fixed clamp 13: Processing feeding means 130: Ball screw 131: Guide rail 132: Motor
133: Movable plate 15: First index feeding means 150: Ball screw 151: Guide rail 153: Movable plate 17: First notch feeding means 170: Ball screw 171: Guide rail 172: Motor 173: Support member 16: Second Index feed means 18: Second notch feed means
61: First processing means 610: Spindle 611: Housing 613: Cutting blade 62: Second processing means 20: Imaging unit 200: Objective lens 201: Low magnification imaging means 202: High magnification imaging means 203: Lighting means
9: Control means 90: Storage unit 91: Machining condition selection unit 92: First determination unit 93: Second determination unit K: Machining condition list

Claims (1)

A wafer processing method using a processing apparatus that holds a wafer in which a device is formed in a region partitioned by a planned division line on a holding table and processes the wafer along the planned division line.
The processing apparatus includes a low-magnification imaging means and a high-magnification imaging means.
A holding step of holding the wafer on the holding table and
A selection process for selecting one machining condition from the machining condition list listing the plurality of machining conditions, and
A first determination step of comparing a storage macro image stored in the processing conditions selected in the selection step with a first image captured by the low-magnification imaging means and determining whether or not both images match. ,
When it is determined in the first determination step that the storage macro image and the first image do not match, the first repetitive step of returning to the selection step and the step of returning to the selection step.
When it is determined in the first determination step that the storage macro image and the first image match, the storage micro image stored in the processing conditions used in the first determination step and the high-magnification imaging. A second determination step of comparing with the second image captured by the means and determining whether or not both images match, and
When it is determined in the second determination step that the memory micro image and the second image do not match, a second repetitive step of returning to the selection step and a second repetitive step.
When it is determined in the second determination step that the stored micro image and the second image match, the wafer is processed under the processing conditions in which the stored micro image used in the second determination step is stored. A method of processing a wafer that includes a process.

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