JP6799467B2 - Wafer processing method - Google Patents

Description

The present invention relates to a method for processing a wafer in which a wafer bonded to a glass plate is divided into individual chips.

The outer peripheral edge of the wafer used for manufacturing the chip package is chamfered in order to prevent chipping or the like during transportation. However, when a wafer whose outer peripheral edge is chamfered is ground and thinned, the outer peripheral edge of the wafer is sharpened like a knife edge, and the wafer is liable to be chipped. Therefore, before grinding the wafer, a process (edge trimming) is performed to remove the chamfered portion of the outer peripheral edge of the wafer by cutting. Further, the laminated wafer formed by laminating two wafers is formed by grinding and thinning a wafer from which the chamfered portion of the outer peripheral edge has been removed and then laminating such a wafer to another wafer. (See, for example, Patent Document 1 below).

Here, in order to form a chip package such as an image sensor and a camera module, a wafer on which a CMOS sensor is formed and a wafer on which a LOGIC-IC is formed are bonded together with, for example, an oxide film to form a two-layer laminated wafer. Is formed, the laminated wafer is adhered to the glass plate, and then the laminated wafer and the glass plate are separated to form individual chips. The glass plate has a certain thickness so that it can be easily attached to the laminated wafer. Therefore, it is necessary to thin the glass plate before dividing it into individual chips. However, as with the above wafer, the outer peripheral edge of the glass plate is also chamfered, so that the outer peripheral edge is formed. When the chamfered glass plate is ground and thinned, the outer peripheral edge of the glass plate is sharpened like a knife edge and easily chipped.

Therefore, in the conventional wafer processing method, for example, as shown in FIG. 16, a two-layer structure laminated wafer 20 formed by laminating a ground semiconductor wafer 21 on a semiconductor wafer 22 before grinding is formed on a glass plate 23. The chamfered portion of the outer peripheral edge 200 of the semiconductor wafer 22 and the chamfered portion of the outer peripheral edge 230 of the glass plate 23 are removed by edge trimming at the same time by the cutting blade 24. Further, after edge trimming only the chamfered portion of the outer peripheral edge 200 of the semiconductor wafer 22 with the cutting blade 24, the semiconductor wafer 22 is ground to a predetermined thickness, and then the chamfered portion of the outer peripheral edge 230 of the glass plate 23 is cut. It can also be removed by 24. After removing the chamfered portion of the outer peripheral edge 230 of the glass plate 23 in this way, a grinding step of grinding and thinning the glass plate 23 and a division starting point forming step of forming a division starting point inside the glass plate 23 are sequentially performed. ing.

Japanese Unexamined Patent Publication No. 2016-4795

However, if the glass plate 23 is ground and thinned before the division starting point is formed inside the glass plate 23 as described above, for example, as shown in FIG. 17, the center O from the outer peripheral edge 230 side of the glass plate 23. There is a problem that cracks 30 are generated toward the surface, and the individualized chips become defective. Further, in the above-mentioned wafer processing method, there is a problem that the processing efficiency is poor because the number of processing steps for the glass plate 23 is increased.

The present invention has been made in view of the above circumstances, and there is a problem to be solved in the method of processing a wafer that can reduce cracks generated in a glass plate.

In the present invention, a bonded wafer in which the surface of a semiconductor wafer whose surface is partitioned by a planned division line and a device is formed and whose outer peripheral edge is chamfered and a glass plate are bonded by an adhesive member and integrated is provided along the planned division line. A method for processing a wafer, which is divided into pieces to form a chip, comprising a semiconductor wafer processing step for processing the semiconductor wafer and a glass plate processing step for processing the glass plate, and the semiconductor wafer processing step is the same. In the chamfer removal step of removing the chamfered portion of the outer peripheral edge of the semiconductor wafer with a cutting blade, the wafer grinding step of grinding the back surface of the semiconductor wafer with a grinding wheel after performing the chamfer removal step, and the wafer grinding step. The glass plate processing is provided with a wafer division starting point forming step of irradiating the semiconductor wafer with a laser beam having a wavelength having a transmittance from the ground back surface side to form a wafer dividing starting point along the planned dividing line. The step is to irradiate the glass plate with a laser beam having a wavelength having transparency to form a glass plate division starting point internally extending in the thickness direction of the glass plate along the planned division line. A forming step and a glass plate grinding step of grinding the glass plate with the grinding wheel are provided, and after performing the semiconductor wafer processing step and the glass plate processing step, a dicing tape is attached to a ring frame having an opening. Along the work set forming step of attaching the glass plate side to the dicing tape exposed from the opening and forming a work set supporting the wafer with the ring frame via the dicing tape, and along the planned division line. A division step of dividing the semiconductor wafer and the glass plate along the planned division line to form a chip by applying an external force to the formed glass plate division starting point and the wafer dividing starting point is provided.

The waiha processing method according to the present invention includes a semiconductor waha processing step for processing a semiconductor waha and a glass plate processing step for processing a glass plate, and the semiconductor waha processing process cuts a chamfered portion of an outer peripheral edge of the semiconductor waha. It has a chamfering removal step of removing with a blade, a waha grinding step of grinding the back surface of the semiconductor wafer with a grinding wheel after performing the chamfering removing step, and a waiha grinding process of grinding the back surface of the semiconductor waha with a grinding wheel, and having transparency to the semiconductor waha from the back surface side ground in the waha grinding process. The glass plate processing step includes a waiha division starting point forming step of irradiating a laser beam of a wavelength to form a waha dividing starting point along a planned division line, and the glass plate processing step irradiates a laser beam having a wavelength that is transparent to the glass plate. Since the glass plate division starting point forming step of forming the glass plate dividing starting point extending in the thickness direction of the glass plate along the planned division line and the glass plate grinding step of grinding the glass plate with a grinding wheel are provided. By forming a glass plate division starting point extending in the thickness direction of the glass plate along the planned division line inside the glass plate and then grinding the glass plate, even during grinding of the glass plate, even if the outer periphery of the glass plate is being ground. Even if cracks occur on the edge side, it is possible to stop the cracks from progressing from the outer peripheral edge side of the glass plate toward the center by the starting point of dividing the glass plate, and it is possible to reduce the possibility of cracks occurring in the glass plate.
After performing the semiconductor wafer processing process and the glass plate processing process, a dicing tape is attached to the ring frame having an opening, the glass plate side is attached to the dicing tape exposed from the opening, and the wafer is attached to the ring frame via the dicing tape. The semiconductor wafer and the glass plate are separated along the planned division line by applying an external force to the workpiece forming step of forming the workpiece to be supported and the glass plate dividing starting point and the wafer dividing starting point formed along the planned dividing line. Since the dicing step of dividing the semiconductor wafer and the glass plate is provided, a good chip can be formed by dividing the semiconductor wafer and the glass plate.
Further, in the waiha processing method according to the present invention, since the chamfer removing step of the chamfered portion of the outer peripheral edge of the glass plate is not performed, the number of processing steps for the glass plate is reduced by at least that step, and the processing efficiency is improved.

It is a perspective view which shows the structure of two semiconductor wafers which make up a laminated wafer. It is sectional drawing which shows the state which chamfered the chamfered portion of the outer peripheral edge of a semiconductor wafer. It is sectional drawing which shows the state which grinds a laminated wafer by a grinding wheel. It is sectional drawing which shows the state of the laminated wafer which one semiconductor wafer was thinned. It is sectional drawing which shows the structure of the bonded wafer. It is sectional drawing which shows the chamfer removal process. It is sectional drawing which shows the wafer grinding process. It is sectional drawing which shows the alignment process. It is sectional drawing which shows the wafer division origin formation process. It is sectional drawing which shows the reversal process and tape peeling process. It is sectional drawing which shows the glass plate division origin formation process. It is sectional drawing which shows the glass plate grinding process. It is a top view which shows the state which the crack generated on the outer peripheral edge side of a glass plate is stopped by the glass plate division origin. It is sectional drawing which shows the work set formation process. It is sectional drawing which shows the division process. It is sectional drawing explaining the processing method of the conventional wafer. It is explanatory drawing which shows the state of the crack generated from the outer peripheral edge of a glass plate in the conventional wafer processing method.

1 Structure of Laminated Wafer As shown in FIG. 1, the semiconductor wafer W1 is an example of an workpiece, and is laminated on, for example, the semiconductor wafer W2 to be formed as a two-layer structure laminated wafer WL. The semiconductor wafers W1 and W2 have, for example, a circular plate-shaped silicon substrate. A device D1 such as a CMOS sensor is formed on the surface W1a of the semiconductor wafer W1 in each region partitioned by the grid-like division schedule line S, and the surface W2a of the semiconductor wafer W2 is formed by the grid-like division schedule line S. A device D2 such as a LOGIC-IC is formed in each of the partitioned regions. On the other hand, the back surface W1b of the semiconductor wafer W1 and the back surface W2b of the semiconductor wafer W2 are surfaces to be processed by grinding with a grinding wheel or laser processing, and are coated with, for example, a nitride film. Further, the chamfered portions of the outer peripheral edges W1c and W2c of the semiconductor wafers W1 and W2 are formed, for example, in the shape of an instep.

Before forming the laminated wafer WL, for example, as shown in FIG. 2, edge trimming is performed in which the chamfered portion of the outer peripheral edge W1c of the semiconductor wafer W1 is removed by the cutting blade 3. While rotating in the direction of arrow A, for example, the cutting blade 3 gradually descends while the outer peripheral side surface of the cutting blade 3 is in contact with the chamfered portion of the outer peripheral edge W1c of the semiconductor wafer W1 and is held by a holding table (not shown). By rotating the semiconductor wafer W1 at least once around a rotation axis in the vertical direction orthogonal to the rotation axis of the cutting blade 3, the chamfered portion is removed and the ring-shaped groove G1 along the outer peripheral edge W1c is formed. It is formed.

As shown in FIG. 3, the semiconductor wafer W1 in which the groove G1 is formed is laminated on the semiconductor wafer W2. In the present embodiment, the surface W1a of the semiconductor wafer W1 is laminated so as to face the surface W2a of the semiconductor wafer W2, thereby forming a laminated wafer WL having a two-layer structure in which the semiconductor wafer W1 and the semiconductor wafer W2 are integrated. To. The laminated wafer WL is in a state in which the surface W1a of the semiconductor wafer W1 and the surface W2a of the semiconductor wafer W2 are electrically connected. In the illustrated example, the semiconductor wafer W1 is on the upper side, the semiconductor wafer W2 is on the lower side, and the back surface W1b of the semiconductor wafer W1 is exposed at the uppermost portion. The method of laminating the semiconductor wafer W1 and the semiconductor wafer W2 is not particularly limited, and for example, the semiconductor wafer W1 can be laminated on the semiconductor wafer W2 via an oxide film.

Next, among the laminated wafers WL, the back surface W1b of the semiconductor wafer W1 is ground by the grinding means 5 for grinding the workpiece. The grinding means 5 includes a spindle 50 in the vertical direction, a grinding wheel 51 mounted on the lower end of the spindle 50, and a grinding wheel 52 annularly fixed to the lower part of the grinding wheel 51, and the entire grinding wheel 5 rotates in the vertical direction. It can rotate around the axis and can move up and down in the vertical direction. The grinding means 5 rotates the spindle 50 while descending in a direction approaching the back surface W1b of the semiconductor wafer W1, rotates the grinding wheel 52 in the direction of arrow B, for example, and rotates around a rotation axis in the vertical direction. While pressing the back surface W1b of the semiconductor wafer W1, grinding is performed until at least the groove G1 is reached. As a result, as shown in FIG. 4, the nitride film is removed from the back surface W1b of the semiconductor wafer W1, and the semiconductor wafer W1 is thinned to a predetermined thickness. After that, a dividing groove G is formed on the back surface W1b of the ground semiconductor wafer W1 along the planned division line S formed on the front surface W1a of the semiconductor wafer W1. The dividing groove G may be formed by, for example, ablation processing for irradiating the laser semiconductor wafer W1 with a laser beam LB having an absorbable wavelength. For example, the cutting blade may be formed in the semiconductor wafer W1 at a predetermined depth. The dividing groove G may be formed by cutting with a laser.

2 Structure of Laminated Wafer As shown in FIG. 5, the laminated wafer WL is adhered to the glass plate 1 to form the bonded wafer 2. The glass plate 1 is made of, for example, a transparent glass member formed in the shape of a circular plate. In the illustrated example, the first surface 1a of the glass plate 1 is the surface to be adhered to which the laminated wafer WL is adhered. On the other hand, the second surface 1b opposite to the first surface 1a is a surface to be attached to which a tape or the like is attached. The chamfered portion of the outer peripheral edge 1c of the glass plate 1 is formed, for example, in the shape of an instep. When adhering the laminated wafer WL to the glass plate 1, for example, the back surface W1b side of the semiconductor wafer W1 is adhered to the first surface 1a of the glass plate 1 by an adhesive member such as a resin (adhesive) or double-sided tape. By fixing, the bonded wafer 2 is formed.

3 Wafer processing method Next, a wafer processing method in which the laminated wafer WL and the glass plate 1 are divided and bonded to form the wafer 2 on individual chips will be described. The processing methods of the wafer are a semiconductor wafer processing step for processing a laminated wafer WL, a glass plate processing step for processing a glass plate 1, a workpiece forming process for forming a work set, and semiconductor wafers W1, W2 and a glass plate 1. It is provided with a division process for dividing the wafer.

(1) Semiconductor Wafer Processing Process The semiconductor wafer processing process shown in the present embodiment includes a chamfering removal step of removing the chamfered portion of the outer peripheral edge Wc of the semiconductor wafer W2, a wafer grinding step of grinding the back surface W2b of the semiconductor wafer W2, and a wafer grinding step. The alignment step of detecting the scheduled division line S and the wafer division starting point forming step of forming the wafer dividing starting point inside the semiconductor wafer W2 are carried out separately.

(1-1) Chamfer Removal Step As shown in FIG. 6, the protective tape 4 is attached to the second surface 1b of the glass plate 1 and the protective tape 4 side is held on a rotating holding table (not shown). Subsequently, for example, the outer peripheral side surface of the cutting blade 3 rotating in the direction of arrow A gradually descends while contacting the chamfered portion of the outer peripheral edge W2c of the semiconductor wafer W2, and the cutting edge of the rotating cutting blade 3 is raised to a predetermined height. Positioned at (the height from the back surface W2b of the semiconductor wafer W2 to the front surface W2a), the bonded wafer 2 is centered on the rotation axis penetrating the center of the bonded wafer 2 in the vertical direction orthogonal to the rotation axis of the cutting blade 3. By rotating the bonded wafer 2 at least once, all the chamfered portions are removed along the outer peripheral edge W2c of the semiconductor wafer W2.

(1-2) Wafer Grinding Step After performing the chamfering removal step, as shown in FIG. 7, the holding table holding the bonded wafer 2 is moved to the lower side of the grinding means 5, and the bonded wafer 2 in the vertical direction is moved. The wafer 2 is rotated around the rotation axis penetrating the center of the wafer. The grinding means 5 rotates the spindle 50 while descending in a direction approaching the back surface W2b of the semiconductor wafer W2, and presses the back surface W2b of the semiconductor wafer W2 while rotating the grinding wheel 52, for example, in the direction of arrow B. Grind to a predetermined thickness. In this way, the nitride film is removed from the back surface W2b of the semiconductor wafer W2, and the semiconductor wafer W2 is thinned to a predetermined thickness.

(1-3) Alignment Step After performing the wafer grinding step, as shown in FIG. 8, the semiconductor wafer W2 is imaged from above by the alignment camera 6 arranged on the upper side of the bonded wafer 2, and pattern matching or the like is performed. By performing the image processing of the above, the alignment for detecting the scheduled division line S shown in FIG. 1 to be laser-processed is performed inside the semiconductor wafer W2.

(1-4) Wafer Division Starting Point Forming Step As shown in FIG. 9, the wafer dividing starting point 8 is formed inside the semiconductor wafer W2 along the planned division line S by using the laser beam irradiation means 7a. The laser beam irradiating means 7a includes at least a laser head 70 that downwardly irradiates a laser beam having a wavelength that is transparent to the semiconductor wafer, and an oscillator (not shown) that oscillates the laser beam. A condenser lens for condensing the laser beam oscillated from the oscillator is built in the laser head 70. The laser beam irradiating means 7a can adjust the position of the focusing point in the vertical direction. That is, the position of the focusing point of the laser beam can be adjusted by moving the laser head 70 in the vertical direction. The position of the condensing point may be adjusted by the condensing lens group.

When the wafer division starting point 8 is formed inside the semiconductor wafer W2, the laser beam irradiating means 7a lowers the laser head 70 in a direction approaching the semiconductor wafer W2, and sets the focusing point of the laser beam LB1 of the semiconductor wafer W2. Adjust to the desired position inside. Subsequently, the bonded wafer 2 is moved in the horizontal direction, and the laser head 70 moves the laser beam LB1 from the back surface W2b side of the semiconductor wafer W2 ground in the wafer grinding step along the scheduled division line S shown in FIG. Irradiate. At this time, since the nitride film is removed from the back surface W2b of the semiconductor wafer W2, the laser beam LB1 is not hindered from being incident on the inside of the semiconductor wafer W2, and the wafer division having a reduced intensity inside the semiconductor wafer W2. The starting point 8 can be formed. In this way, when the laser beam LB1 is irradiated along all the scheduled division lines S to form the wafer division starting point 8, the wafer division starting point forming step is completed. The wafer division starting point forming step may be performed at least before the division step described later is performed. Further, in order to facilitate the incident of the laser beam LB1 by the semiconductor waiha W2, a member (for example, resin) having a refractive index larger than that of air and smaller than the refractive index of the semiconductor waha W2 is applied to the surface of the semiconductor waha W2 on which the laser beam LB1 is incident. It is preferable to dry it to form a layer. This layer may be peeled off together with the protective tape 4a when the protective tape 4a is peeled off in the work set forming step described later, or may be peeled off after the dividing step described later.

(2) Glass plate processing step In the glass plate processing step shown in the present embodiment, the bonding wafer 2 is inverted and the protective tape 4 is peeled off, the tape peeling step, the alignment step, and the inside of the glass plate 1. The process is divided into a glass plate division starting point forming step for forming the glass plate dividing starting point and a glass plate grinding step for grinding the second surface 1b of the glass plate 1.

(2-1) Inversion Step and Tape Peeling Step As shown in FIG. 10, the front and back surfaces of the bonded wafer 2 are inverted, the glass plate 1 is on the upper side, the laminated wafer WL is positioned on the lower side, and the glass plate 1 is placed. The protective tape 4 is peeled off from the second surface 1b. As a result, the second surface 1b of the glass plate 1 is exposed at the uppermost portion. When carrying out the glass plate processing step, since the laminated wafer WL side is held by the holding table, it is preferable to attach, for example, a protective tape 4a to the semiconductor wafer W2 located at the lowermost portion.

(2-2) Alignment Step Before forming the starting point for dividing the glass plate inside the glass plate 1, an image is taken from above the bonded wafer 2 by the above alignment camera 6 and image processing such as pattern matching is performed. , The inside of the glass plate 1 is aligned to detect the scheduled division line S directly below the position to be laser-processed. Since the glass plate 1 is transparent and the nitride film is removed from the back surface W1b of the ground semiconductor wafer W1 bonded to the first surface 1a of the glass plate 1, the alignment camera 6 is used. The scheduled division line S can be easily detected.

(2-3) Glass Plate Division Starting Point Forming Step As shown in FIG. 11, the glass plate dividing starting point 9 is formed at a predetermined position inside the glass plate 1 by using the laser beam irradiation means 7b. When the glass plate dividing starting point 9 is formed inside the glass plate 1, the laser beam irradiating means 7b lowers the laser head 70 in a direction approaching the glass plate 1 and has a wavelength transparent to the glass plate 1. The focusing point of the laser beam LB2 is adjusted to a desired position inside the glass plate 1 (the position closest to the first surface 1a side of the glass plate 1 in the illustrated example). Subsequently, the bonded wafer 2 is moved in the horizontal direction, and the laser head 70 transmits a laser beam LB2 having a wavelength that is transparent to the glass plate 1 from the second surface 1b side of the glass plate 1 to FIG. Irradiation is performed along the indicated division schedule line S to form a glass plate division starting point 9 inside the glass plate 1. The glass plate division starting point 9 shown in the present embodiment is a plurality of fine holes forming a row, and the glass plate 1 is easily broken by forming the glass plate dividing starting point 9 inside.

Here, the laser beam irradiating means 7b extends in the thickness direction of the glass plate 1 at a predetermined interval, and arranges a plurality of glass plate division starting points 9 in the extending direction of the planned division line S shown in FIG. It is good to let it form. That is, fine holes arranged along all the planned division lines S are formed inside the glass plate 1. Specifically, the laser head 70 is moved in the vertical direction to position the focusing point (condensing area) of the thin laser beam LB2 inside the glass plate 1 to form a fine hole opened on the first surface 1a. .. The distance between the glass plate division starting points 9 is, for example, about 5 μm. In addition, an annular alteration layer AL is formed around the fine pores. This altered layer AL forms a region to which thermal stress (force in the direction of spreading around the minute pores) when forming fine pores is applied, and when fine pores are formed at the above intervals, the altered layer AL is formed. Are connected and formed. Further, in the above example, the condensing point (condensing area) of the laser beam LB2 is positioned inside the glass plate 1, but it may be positioned near the first surface 1a or on the surface of the first surface 1a. .. The fine holes do not have to penetrate from the first surface 1a to the second surface 1b. The altered layer AL may be formed in the thickness direction of the glass plate 1.

(2-4) Glass Plate Grinding Process As shown in FIG. 12, the second surface 1b of the glass plate 1 is ground to a predetermined thickness by the grinding means 5 to be thinned. Specifically, the holding table holding the bonded wafer 2 is moved to the lower side of the grinding means 5, and the bonded wafer 2 is rotated around a rotation axis penetrating the center of the bonded wafer 2 in the vertical direction. The grinding means 5 rotates the spindle 50 while descending in a direction approaching the second surface 1b of the glass plate 1, and rotates the grinding wheel 52 in the direction of arrow B, for example, while rotating the second surface 1b of the glass plate 1. Grinding to a predetermined thickness while pressing the surface 1b of. At this time, as shown in FIG. 13, even if a crack 10 is generated on the outer peripheral edge 1c side of the glass plate 1 due to grinding, the glass is formed at the plurality of glass plate division starting points 9 formed inside the glass plate 1. It is possible to stop the crack 10 from progressing from the outer peripheral edge 1c side of the plate 1 toward the center O. As a result, the glass plate 1 can be thinned to a predetermined thickness in a good condition inside the glass plate 1.

(3) Workset forming step After performing the semiconductor wafer processing step and the glass plate processing step, as shown in FIG. 14, the front and back sides of the bonded wafer 2 are inverted, the laminated wafer WL is on the upper side, and the glass plate 1 is placed. The dicing tape 12 is attached to the ring frame 11 having an opening, which is positioned on the lower side, the glass plate 1 side is attached to the dicing tape 12 exposed from the opening, and the wafer is attached to the ring frame 11 via the dicing tape 12. A work set 13 that supports 2 is formed. Further, the protective tape 4a is peeled off from the back surface W2b of the semiconductor wafer W2.

(4) Division process As shown in FIG. 15, for example, the work set 13 is supported by the support table 14, and the laminated wafers are laminated along the planned division line S by the braking blades 15 arranged on the upper side of the support table 14. The WL and the glass plate 1 are divided. A gap 140 is formed in the support table 14, and the bonded wafer 2 can be supported via the dicing tape 12. The tip portion 15a of the braking blade 15 is formed in a straight line along the straight line of the planned division line S shown in FIG. 1, and an external force can be applied to the inside of the workpiece. A pressing means 16 is connected to the braking blade 15 so that it can move in the vertical direction.

First, in order to align the scheduled division line S of the semiconductor wafer W2 with the braking blade 15, the scheduled division line S is detected by an alignment camera (not shown). Subsequently, the work set 13 is placed on the support table 14 with the dicing tape 12 side facing downward. At this time, by moving one scheduled division line S inside the gap 140 of the support table 14, the wafer division starting point 8 formed along the one scheduled division line S on the upper side of the gap 140 is divided. The groove G and the glass plate division starting point 9 are positioned. Next, the tip portion 15a of the braking blade 15 is positioned at a position directly above the planned division line S in which the wafer division start point 8, the division groove G, and the glass plate division start point 9 are formed.

The pressing means 16 lowers the braking blade 15 in a direction approaching the work set 13 and presses the braking blade 15 downward from the back surface W2b side of the semiconductor wafer W2 by the tip portion 15a of the braking blade 15 to form the planned division line S. An external force (bending stress) is applied to the wafer division starting point 8, the dividing groove G, and the glass plate dividing starting point 9. As a result, the portions of the work set 13 located above the gap 140 are pushed downward, and the semiconductor wafers W2, W1 and the glass plate 1 that cannot withstand the bending stress have the wafer division starting point 8, the division groove G and the glass. The board is divided starting from the plate division starting point 9.

After splitting along one scheduled split line S, the work set 13 is indexed in the direction of arrow Y, for example, and the adjacent scheduled split line S is moved inside the gap 140 of the support table 14 to move the braking blade. After positioning and aligning the tip portion 15a of 15 at a position where it can come into contact with the planned division line S, the adjacent planned division line S is pressed by the braking blade 15, and the wafer division starting point 8, the division groove G and the glass plate are pressed. An external force (bending stress) is applied to the division starting point 9. In this way, when the semiconductor wafers W2, W1 and the glass plate 1 are divided along all the planned division lines S by the braking blade 15, the division process is completed. As a result, the semiconductor wafers W1 and W2 and the glass plate 1 are formed on individual chips.

As described above, in the waiha processing method according to the present invention, after performing the semiconductor waiha processing step, the glass plate 1 is divided by irradiating the glass plate 1 with a laser beam LB2 having a wavelength having a transmittance. After performing the glass division starting point forming step of forming the glass plate dividing starting point 9 extending in the thickness direction of the glass plate 1 along the planned line S inside, the glass plate 1 is ground by the grinding wheel 52. Since the process is configured to be carried out, even if a crack 10 occurs on the outer peripheral edge 1c side of the glass plate 1 during grinding of the glass plate 1, the glass plate division starting point 9 moves from the outer peripheral edge 1c side to the center O. It is possible to stop the progress of the crack 10 toward the glass plate 1 and reduce the possibility of cracking in the glass plate 1. After the semiconductor wafer processing step and the glass plate processing step are carried out, the work set forming step and the dividing step are sequentially carried out, so that the semiconductor wafers W1 and W2 and the glass plate 1 can be divided to form a good chip. ..
Further, in the wafer processing method according to the present invention, since the chamfer removal step of the chamfered portion of the outer peripheral edge 1c of the glass plate 1 is not performed, the number of processing steps for the glass plate 1 is reduced by at least that step, and the processing efficiency is improved. improves.

In the present embodiment, the semiconductor wafer bonded to the glass plate 1 has been described as a laminated wafer WL having a two-layer structure, but the present invention is not limited to this, and the semiconductor wafer bonded to the glass plate 1 is one layer. It may be 3 layers or more.

1: Glass plate 1a: First surface 1b: Second surface 1c: Outer peripheral edge 2: Laminated wafer 3: Cutting blade 4, 4a: Protective tape 5: Grinding means 50: Spindle 51: Grinding wheel 52: Grinding grindstone 6: Alignment cameras 7a, 7b: Laser beam irradiation means 70: Laser head 8: Wafer division starting point 9: Glass plate dividing starting point 10: Crack 11: Ring frame 12: Dicing tape 13: Workset 14: Support table 140: Gap 15 : Pressing means 150: Braking blade 151: Elevating means 20: Laminated wafers 21 and 22: Semiconductor wafers 23: Glass plate 24: Cutting blades 30: Cracks W1, W2: Semiconductor wafers W1a, W2a: Front surface W1b, W2b: Back surface W1c , W2c: Outer peripheral edge S: Scheduled division line D1, D2: Device WL: Laminated wafer G: Division groove AL: Altered layer

Claims (1)

The surface of the semiconductor wafer, which is partitioned by the planned division line on the surface and the device is formed and the outer peripheral edge is chamfered, and the glass plate are bonded by an adhesive member and integrated, and the bonded wafer is divided along the planned division line. A method for processing wafers that form chips.
A semiconductor wafer processing process for processing the semiconductor wafer and a glass plate processing process for processing the glass plate are provided.
The semiconductor wafer processing step includes a chamfer removing step of removing the chamfered portion of the outer peripheral edge of the semiconductor wafer with a cutting blade.
After performing the chamfering step, a wafer grinding step of grinding the back surface of the semiconductor wafer with a grinding wheel, and a wafer grinding step.
A wafer division starting point forming step of irradiating the semiconductor wafer with a laser beam having a wavelength having a transmittance from the back surface side ground in the wafer grinding step to form a wafer dividing starting point along the planned dividing line is provided. ,
In the glass plate processing step, the glass plate is irradiated with a laser beam having a wavelength having transparency, and a glass plate division starting point extending in the thickness direction of the glass plate is formed inside along the planned division line. Glass division starting point formation process and
The glass plate is provided with a glass plate grinding process for grinding the glass plate with the grinding wheel.
After performing the semiconductor wafer processing step and the glass plate processing step, a dicing tape is attached to a ring frame having an opening, the glass plate side is attached to the dicing tape exposed from the opening, and the dicing tape is used. The work set forming step of forming the work set supporting the wafer with the ring frame, and
By applying an external force to the glass plate division starting point and the wafer dividing starting point formed along the planned division line, the semiconductor wafer and the glass plate are divided along the planned dividing line to form a chip. Wafer processing method including a division process.

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