JP4590064B2 - Semiconductor wafer dividing method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a semiconductor wafer dividing method in which a semiconductor wafer having a plurality of circuits (chips) partitioned by streets formed on the surface is divided for each chip.
[0002]
[Prior art]
For example, in the manufacture of a semiconductor device, the surface of a substantially disk-shaped semiconductor wafer is divided into a plurality of rectangular areas by cutting lines called streets arranged in a grid pattern, and each rectangular area has a predetermined area. This circuit (chip) is formed. In this way, a plurality of rectangular regions each provided with a circuit (chip) are individually cut and separated to form a so-called semiconductor chip. The semiconductor wafer is cut by a precision cutting device generally called a dicing device. In this dicing apparatus, a rotating blade having a thickness of about 20 μm is cut along a street formed on the surface of a semiconductor wafer while rotating at a high speed, and is divided into individual chips. As a method for dividing a semiconductor wafer, a point scriber such as glass cutting or cutting with a laser beam has been tried.
[0003]
[Problems to be solved by the invention]
Thus, the semiconductor wafer is divided by the dicing device in a form in which the cutting grooves are formed by gradually breaking while applying an impact force to the streets by a rotating blade rotating at high speed. Multiple fine chips of μm or more occur. Therefore, since the chip formed on the semiconductor wafer must be provided in a range that does not cause chipping that occurs during cutting, a street width of about 50 μm is required when cutting with a dicing apparatus. However, in order to improve the productivity of semiconductor chips, the problem is how many chips can be formed on a single semiconductor wafer. For this purpose, how to reduce the width of the street where no chips are formed. The problem is whether it can be narrowed. On the other hand, cutting with a point scriber or a laser beam is not necessarily satisfactory in terms of productivity because the cutting width itself is narrow but the yield of the product due to cracking is poor.
[0004]
The present invention has been made in view of the above-mentioned facts, and the main technical problem thereof is a method for dividing a semiconductor wafer, which can reduce the width of the street and improve the yield of the product and improve the productivity. Is to provide.
[0005]
[Means for Solving the Problems]
In order to solve the main technical problem, according to the present invention, there is provided a semiconductor wafer dividing method in which a plurality of chips partitioned by streets are formed on the surface, and the semiconductor wafer is divided into chips.
A scribing process for generating a split guide line by forming a scribe line of a wafer along one side of the surface of the semiconductor wafer from one end to the other by a scriber ;
A tape adhering step of adhering a tape to the surface of the semiconductor wafer on which the split guide wires are generated; and
A back surface cutting step of generating a cutting groove by using a rotating blade on the back surface of the semiconductor wafer to which the tape is attached, along the divided guide lines, and generating a cutting groove;
The cutting groove is guided to the dividing guide line and the uncut portion is completely divided and divided into chips.
A method for dividing a semiconductor wafer is provided.
[0006]
It is preferable that the rotating blade has a V-shaped or rounded tip, and the cutting groove leaves an uncut portion of 20 to 50 μm along the dividing guide line.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of a semiconductor wafer dividing method according to the present invention will be described in detail with reference to the accompanying drawings.
[0008]
FIG. 1 shows each processing step of the method for dividing a semiconductor wafer according to the present invention.
In the method for dividing a semiconductor wafer according to the present invention, a scribe line is formed along streets 4 formed between circuits (chips) 3 provided on the surface of the semiconductor wafer 2 as shown in FIG. A scribing process for generating the divided guide lines 5, a tape attaching process for attaching the tape 7 to the surface of the semiconductor wafer 2 on which the divided guide lines 5 are generated, as shown in FIG. (C), a back surface cutting step of generating a cutting groove 6 along the division guide line 5 on the back surface of the semiconductor wafer 2 is included. Hereinafter, the above steps will be described in more detail.
[0009]
The scribe process will be described with reference to FIGS.
FIG. 2 shows an embodiment of a scribing apparatus for performing the scribing process. The scribing device shown in FIG. 2 includes a device housing 1 having a substantially rectangular parallelepiped shape. In the apparatus housing 1, a chuck table 9 for holding a workpiece is disposed so as to be movable in a direction indicated by an arrow X that is a machining feed direction. The chuck table 9 includes a suction chuck support 91 and a suction chuck 92 mounted on the suction chuck support 91, and a workpiece, such as a disk-shaped semiconductor wafer 2, is a workpiece on the suction chuck 92. Is held by suction means (not shown). The chuck table 9 is configured to be rotatable by a rotation mechanism (not shown).
[0010]
The scribing apparatus in the illustrated embodiment includes a scribing mechanism 20 that generates a split guide line 5 by forming a scribe line along the street 4 of the semiconductor wafer 2 held on the chuck table 9 described above. The scribe mechanism 20 will be described with reference to FIGS. 3 and 4. The scribe mechanism 20 includes a moving base 21, a scriber support member 23 supported at one end of the moving base 21 by a support shaft 22 so as to be swingable in the vertical direction, and a rotational support supported at the other end of the scriber support member 23. A roller scriber 25 rotatably supported by a shaft 24 and pressing force urging means 26 for applying a pressing force to the scriber support member 23 are provided. The movable base 21 is disposed on a support base (not shown) so as to be movable in a direction indicated by an arrow Y in FIG. 2, which is an indexing direction (a direction perpendicular to the paper surface in FIG. 3). The roller scriber 25 is formed of sintered diamond, and is rotatably supported on the other end of the scriber support member 23 by a rotation support shaft 24 disposed in a direction perpendicular to the paper surface in FIG. The pressing force urging means 26 includes an adjustment screw 261 screwed into a support portion 211 formed to protrude from the upper end of the moving base 21, a spring receiving plate 262 attached to the lower end of the adjustment screw 261, It comprises a coil spring 263 disposed between the spring receiving plate 262 and the upper surface of the scriber support member 23. In the illustrated embodiment, an example in which the coil spring 263 and the adjusting screw 261 are used as the pressing force urging means is shown. However, the air pressure is adjusted by using an air piston as the pressing force urging means and adjusting the air pressure. You may control. In addition, the scribing apparatus in the illustrated embodiment includes an alignment unit 30 including a microscope and a CCD camera. As shown in FIG. 4, the hairline (reference line) 301 formed on the microscope of the alignment means 30 and the outer peripheral contact portion of the roller scriber 25 of the scribe mechanism 20 are adjusted so as to be located on the same line. In the illustrated embodiment, the scribe mechanism 20 uses the roller scriber 25, but a point scriber may be used instead of the roller scriber 25.
[0011]
Next, the example which implements the said scribe process in this invention with the scribe apparatus mentioned above is demonstrated.
First, the semiconductor wafer 2 is placed on the suction chuck 92 of the chuck table 9 by, for example, an operator. At this time, the semiconductor wafer 2 is placed with the surface facing up. The semiconductor wafer 2 placed on the suction chuck 92 is suction-held by the suction means (not shown) with the front surface facing up on the suction chuck 92. In this way, the chuck table 9 that sucks and holds the semiconductor wafer 2 is moved to just below the alignment means 30. When the chuck table 9 is positioned immediately below the alignment means 30, the alignment means 30 detects the street 4 formed on the semiconductor wafer 2, and moves and adjusts it in the arrow Y direction, which is the indexing direction of the scribe mechanism 20, so that the precise position is obtained. Matching work is performed. Thereafter, the roller scriber 25 rolls on the street 4 of the semiconductor wafer 2 held by the chuck table 9 by moving the chuck table 9 holding the semiconductor wafer 2 by suction in the direction indicated by the arrow X which is the machining feed direction. Is done. As a result, a scribe line is formed along the street 4 and the division guide line 5 is generated. In addition, as for the production | generation of the division | segmentation guide wire 5 by the roller scriber 25, it is desirable to implement under the load of 50-150g. This load can be adjusted by advancing and retracting the adjusting screw 261 of the pressing force urging means 26. Then, with respect to all the streets 4 formed on the semiconductor wafer 2, the feed in the arrow Y direction that is the indexing direction of the scribe mechanism 20 and the feed in the arrow X direction that is the machining feed direction of the chuck table 9 are sequentially repeated. As shown in FIG. 6, the division guide lines 5 can be generated along the streets 4 in the semiconductor wafer 2.
[0012]
After the scribing process for generating the split guide lines 5 along the streets 4 of the semiconductor wafer 2 is completed in this way, the chuck table 9 holding the semiconductor wafer 2 returns to the position where the semiconductor wafer 2 is first sucked and held. Here, the suction holding of the semiconductor wafer 2 is released. Therefore, the division guide wire 5 is generated by the scribing process, and the semiconductor wafer 2 can be taken out from the chuck table 9.
[0013]
Thus, if the division | segmentation guide wire 5 was produced | generated along the street 4 of the semiconductor wafer 2, the tape sticking process mentioned above will be implemented. That is, as shown in FIG. 1 (b), the tape 7 is adhered to the surface of the semiconductor wafer 2 on which the divided guide lines 5 are generated. Therefore, the surface of each chip 3 formed on the surface of the semiconductor wafer 2 is adhered to the tape 7.
[0014]
If the tape sticking process is performed as described above, the back surface cutting process is performed. Here, a dicing apparatus that is a cutting device for performing the back surface cutting process will be described with reference to FIGS. 7 and 8.
The dicing apparatus in the illustrated embodiment includes a device housing 10 having a substantially rectangular parallelepiped shape. In the apparatus housing 10, a chuck table 11 that holds a workpiece is disposed so as to be movable in a direction indicated by an arrow X that is a cutting feed direction. The chuck table 11 includes a suction chuck support base 111 and a suction chuck 112 mounted on the suction chuck support base 111, and a workpiece such as a disk-shaped semiconductor wafer 2 is a workpiece on the suction chuck 112. Is held by suction means (not shown). Further, the chuck table 11 is configured to be rotatable by a rotation mechanism (not shown).
[0015]
The dicing apparatus in the illustrated embodiment includes a spindle unit 40 as cutting means. The spindle unit 40 is mounted on a moving base (not shown) and is adjusted to move in a direction indicated by an arrow Y that is an indexing direction and a direction indicated by an arrow Z that is a cutting direction, and the spindle housing 41 is freely rotatable. And a rotary spindle 42 that is rotated by a rotary drive mechanism (not shown), and a rotary blade 43 attached to the rotary spindle 42. The rotating blade 43 is a V blade in the illustrated embodiment. Further, the alignment means 30 in the illustrated dicing apparatus includes an infrared CCD camera.
[0016]
As shown in FIG. 7, the dicing apparatus in the illustrated embodiment includes a cassette 12 for stocking the semiconductor wafer 2 as a workpiece, a workpiece unloading means 13, a workpiece conveying means 14, a cleaning means 15, And a cleaning and conveying means 16. The cassette 12 is placed on a cassette table 121 arranged so as to be movable up and down by lifting means (not shown).
[0017]
Next, the example which implements the said back surface cutting process in this invention with the cutting device mentioned above is demonstrated.
The tape 7 attached to the surface of the semiconductor wafer 2 in the tape attaching process is attached to the frame 8, and the semiconductor wafer 2 is attached to the cassette 12 in a state of being attached to the frame 8 via the tape 7. Be contained. Therefore, the semiconductor wafer 2 mounted on the frame 8 is accommodated with the back side up.
A semiconductor wafer 2 mounted on a frame 8 accommodated in a predetermined position of the cassette 12 (hereinafter, the semiconductor wafer 2 mounted on the frame 8 is simply referred to as a semiconductor wafer 2) is moved up and down by a lifting / lowering means (not shown). When 121 moves up and down, it is positioned at the unloading position. Next, the workpiece unloading means 13 moves forward and backward to unload the semiconductor wafer 2 positioned at the unloading position to the workpiece placement area 18. The semiconductor wafer 2 carried out to the workpiece mounting area 18 is transferred onto the chucking chuck 112 of the chuck table 11 by the turning operation of the workpiece transfer means 14, and the surface of the chucking chuck 112 with the back surface facing up. The side is held by suction. At this time, the frame 8 on which the semiconductor wafer 2 is mounted via the tape 7 is fixed by a clamp 113 provided on the chuck table 11. In this way, the chuck table 11 holding the semiconductor wafer 2 by suction is moved to a position directly below the alignment means 30. When the chuck table 11 is positioned directly below the alignment means 30, the alignment guide 30 detects the division guide wire 5 generated on the street 4 of the semiconductor wafer 2 in the scribing process, and the arrow Y indicating the indexing direction of the spindle unit 40. Fine alignment work is performed by moving and adjusting in the direction. In addition, since the semiconductor wafer 2 has the tape 7 attached to the surface (the surface on the side where the divided guide wires 5 are generated) in the tape attaching step, the back surface is positioned on the upper side. Since 30 is equipped with an infrared CCD camera, it is possible to detect the divided guide lines 5 generated on the lower surface.
[0018]
Thereafter, by moving the chuck table 11 that sucks and holds the semiconductor wafer 2 in the direction indicated by the arrow X that is the cutting feed direction, the cutting grooves 6 are generated along the divided guide lines 5 from the back surface side of the semiconductor wafer 2. Can do. At this time, the cutting amount by the rotating blade 43 is set to a position of 20 to 50 μm from the surface of the street 4 where the division guide wire 5 is formed. That is, in the back surface cutting process, the semiconductor blade 2 is provided with a 20-50 μm uncut portion from the surface of the street 4 along the divided guide lines 5 from the back surface side by the rotating blade 43 to generate the cutting grooves 6. As described above, the cutting groove 6 is generated by providing a cut portion of 20 to 50 μm from the surface of the street 4 along the divided guide line 5, whereby the semiconductor wafer 2 is guided to the divided guide line 5 and left uncut. The part is completely divided. Then, with respect to the all-divided guide wire 5 formed on the semiconductor wafer 2, the feed in the arrow Y direction that is the indexing direction of the spindle unit 40 and the feed in the arrow X direction that is the cutting feed direction of the chuck table 11 are performed. Can be divided into each chip 3 as shown exaggeratedly in FIG. The divided semiconductor chips are not separated by the action of the tape 7, and the state of the semiconductor wafer 2 mounted on the frame 8 is maintained.
[0019]
As described above, in the illustrated embodiment, an uncut portion is provided along the split guide line 5 from the back surface of the split guide line 5 generated by the scribe line formed on the street 4 of the semiconductor wafer 2 to form the cutting groove 6. Is generated, and the uncut portion is guided by the dividing guide line 5 and is divided into chips, so that the width of the street 4 formed on the surface of the semiconductor wafer 2 can be extremely narrowed. Become. Therefore, since the width of the street 4 can be reduced to 10 μm or less, a large number of chips can be formed on the surface of the semiconductor wafer 2 and the productivity can be improved. Further, in the illustrated embodiment, a cutting groove 6 with high reliability is generated by providing an uncut portion along the division guide line 5 from the back surface of the division guide line 5 formed on the street 4 of the semiconductor wafer 2. Therefore, there is no occurrence of cracking or the like as in the case of cutting with a point scriber or a laser beam, and the yield of the product is good and the productivity can be improved. In the illustrated embodiment, the V blade is used as the rotating blade 43. However, the rotating blade 43 is a blade having a rounded tip as indicated by a two-dot chain line in FIG. May be used.
[0020]
After the semiconductor wafer 2 is divided into chips in this way, the chuck table 11 holding the semiconductor wafer 2 is returned to the position where the semiconductor wafer 2 is first sucked and held, and the suction holding of the semiconductor wafer 2 is released here. At the same time, the fixing of the frame 8 by the clamp 113 is also released. Next, the semiconductor wafer 2 is transferred to the cleaning unit 15 by the cleaning transfer unit 16 and cleaned there. The semiconductor wafer 2 cleaned in this manner is carried out to the workpiece placement region 18 by the workpiece conveying means 14. Then, the semiconductor wafer 2 is stored in a predetermined position of the cassette 12 by the workpiece unloading means 13. Although the semiconductor wafer 2 divided into each chip maintains the form of the semiconductor wafer by the tape 7, since it is divided into individual chips, adjacent chips may be rubbed and damaged during transportation. There is. That is, when the semiconductor wafer is divided into chips by cutting with a dicing apparatus that is generally performed in the related art, a gap having a thickness of the cutting blade (about 20 μm) is formed between the chips. However, each chip divided by the dividing method according to the present invention is provided with the uncut portion by the cutting blade 43 as described above and the cutting groove 6 is generated and divided, so that the divided surfaces are substantially in contact with each other. Yes. For this reason, when the tape 7 is bent downward by its own weight, the chips rub against each other in the center direction.
[0021]
It is desirable to prevent rubbing between chips during the above-described conveyance. In order to prevent rubbing between chips during conveyance, the interval between the chips may be increased, and the following measures can be considered.
In the first measure, the space between the chips is widened by pressing the space between the tapes attached to the chips with a frame such as an embroidery frame and expanding the entire tape. The second measure is that the frame on which the divided chips are mounted via the tape is turned upside down so that the surface to which the chips are attached is on the lower side, and the tape 7 is moved downward by the weight of each divided chip. The distance between the chips is widened by flexing to the right.
[0022]
【The invention's effect】
Since the semiconductor wafer dividing method according to the present invention is configured as described above, the following operational effects can be obtained.
[0023]
That is, according to the present invention, a scribe line is formed along the street on the surface of the semiconductor wafer to generate a division guide line, a tape is attached to the surface of the semiconductor wafer, and then along the division guide line from the back surface. By creating the cutting groove by providing the uncut portion, the uncut portion is completely divided by being guided by the dividing guide line and divided for each chip, so that the width of the street formed on the surface of the semiconductor wafer is extremely narrow. It becomes possible to do. Therefore, since the street width can be 10 μm or less, a large number of chips can be formed on the surface of the semiconductor wafer, and productivity can be improved. Further, in the illustrated embodiment, the chip is divided into each chip by providing a cut-off portion along the division guide line from the back surface of the division guide line formed on the street of the semiconductor wafer to generate a highly reliable cutting groove. Therefore, there is no occurrence of cracking or the like as in the case of cutting with a point scriber or a laser beam, and the yield of the product is good and the productivity can be improved.
[Brief description of the drawings]
FIG. 1 is an explanatory view showing each step of a method for dividing a semiconductor wafer according to the present invention.
FIG. 2 is a perspective view showing an embodiment of a scribing apparatus for performing a scribing process of a semiconductor wafer dividing method according to the present invention.
FIG. 3 is a front view of a scribe mechanism provided in the scribe device shown in FIG. 2;
4 is an explanatory view showing a relationship between a roller scriber and an alignment unit of a scribe mechanism equipped in the scribe device shown in FIG. 2;
5 is a perspective view of main parts of the scribing device shown in FIG. 2. FIG.
6 is a perspective view of a semiconductor wafer in which split guide lines are generated by the scribing apparatus shown in FIG.
FIG. 7 is a perspective view showing an embodiment of a dicing apparatus as a cutting apparatus for performing a back surface cutting step of the semiconductor wafer dividing method according to the present invention.
FIG. 8 is a perspective view of main parts of the dicing apparatus shown in FIG.
FIG. 9 is a front view of a chip divided by the method for dividing a semiconductor wafer according to the present invention.
[Explanation of symbols]
1: Device housing of scribing device 2: Semiconductor wafer 3: Circuit (chip)
4: Street 5: Dividing guide wire 6: Cutting groove 7: Tape 8: Frame 9: Scrub device chuck tail 91: Suction chuck support base 92: Suction chuck 10: Device housing of dicing device 11: Chuck tail 111 of dicing device : Suction chuck support 112: suction chuck 113: clamp 12: cassette 13: workpiece unloading means 14: workpiece transport means 15: cleaning means 16: cleaning transport means 20: scribing mechanism 21: moving base of the scribing mechanism 23: Scribing mechanism scriber support member 25: Scribing mechanism roller scriber 26: Scribing mechanism pressing force biasing means 30: Alignment means 40: Spindle unit 41: Spindle housing 42: Rotating spindle 43: Rotating blade

Claims (2)

A method of dividing a semiconductor wafer, wherein a plurality of chips partitioned by streets are formed on the surface, and the semiconductor wafer is divided into chips.
A scribing process for generating a split guide line by forming a scribe line of a wafer along one side of the surface of the semiconductor wafer from one end to the other by a scriber ;
A tape adhering step of adhering a tape to the surface of the semiconductor wafer on which the divided guide lines are generated; and
A back surface cutting step of generating a cutting groove by using a rotating blade on the back surface of the semiconductor wafer to which the tape is attached, along the divided guide lines, and generating a cutting groove;
The cutting groove is guided to the dividing guide line and the uncut portion is completely divided and divided into chips.
A method of dividing a semiconductor wafer. The wafer dividing method according to claim 1 , wherein the rotating blade has a V-shaped or rounded tip, and the cutting groove leaves a 20-50 μm uncut portion along the dividing guide line. .

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