JP2814176B2 - Semiconductor wafer splitting method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for dividing a semiconductor wafer.

[0002]

2. Description of the Related Art Conventionally, in order to form a thin and small chip, the back surface is polished prior to dicing of a semiconductor wafer, polished to a predetermined thickness, and then the semiconductor wafer is diced and divided into chips. . However, according to this method, in the case of a large-sized semiconductor wafer having a diameter of 150 mm, 200 mm or the like, if it is polished and finished to a thickness of, for example, about 300 μm, damage such as breakage or chipping is likely to occur after polishing, and handling becomes difficult. Further, there is also a disadvantage that backside chipping occurs when dicing a semiconductor wafer.

[0003]

SUMMARY OF THE INVENTION The present invention has been made to solve such a conventional problem. In particular, a thin and small chip can be formed without damaging even a large semiconductor wafer, and backside chipping can be achieved. An object of the present invention is to provide a method for dividing a semiconductor wafer which can be eliminated.

[0004]

SUMMARY OF THE INVENTION As a means for technically solving this problem, the present invention is a method for dividing a semiconductor wafer into chips, wherein the semiconductor wafer is polished prior to polishing the back surface of the semiconductor wafer. Dicing, and a step of storing the chip with the back side up in a storage hole of a substrate that stores the chip divided by dicing, and a step of polishing the back surface of the chip fixed to the substrate. The gist is a method of dividing a semiconductor wafer to be configured.

[0005]

[Operation] A semiconductor wafer is diced first and the back surface of the semiconductor wafer divided by the dicing is polished. In other words, since the back surface is thinly polished into chips, it is necessary to polish the back surface of a large semiconductor wafer. At the same time, backside chipping caused by dicing can be removed by polishing.

[0006]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of the present invention. In FIG. 1, reference numeral 1 denotes a chuck table on which a semiconductor wafer 2 divided by dicing is fixed via a frame 3.

As shown in FIG. 2, the semiconductor wafer 2 is placed in a known dicing apparatus (for example, Japanese Patent Publication No. 3-11601).
No. 2, pp. 157-334, etc., the chips 4 are divided into chips 4 in advance, and these chips 4 are attached to the adhesive tape 5 of the frame 3 with the back surface 4a facing up after dicing.

Reference numeral 6 denotes a polishing grindstone which can polish the back surface 4a of the semiconductor wafer 2, that is, the chip 4 fixed on the chuck table 1 via the frame 3. As the polishing apparatus 7 including such a polishing grindstone 6 and the chuck table 1, for example, the one described in Japanese Patent Publication No. 64-3620 can be used.

In this manner, the semiconductor wafer 2 is first divided into chips 4 by a dicing step, and after dicing, these chips 4 are attached to the adhesive tape 5 of the frame 3 with the back surface 4a facing upward as described above. Then, the frame 3 is fixed on the chuck table 1 of the polishing device 7, and a polishing step of polishing the back surface 4 a of the chip 4 with the polishing stone 6 is performed.

When the semiconductor wafer 2 is diced first in the dicing step, chipping 4b usually occurs around the back surface 4a of the chip 4 as shown in FIG. 3, but the back surface 4a of the chip 4 is polished in a subsequent polishing step. To be
As shown in FIG. 4, the chip 4 'which has been polished is wiped off so that the chipping is sharply removed and the chipping problem is solved.

Further, since it is not necessary to handle a large-sized semiconductor wafer which has been thinly polished as in the prior art, damage such as breakage or chipping of the semiconductor wafer can be prevented.

[0012] After the dicing, the operation of replacing the chip with the back side facing upward is performed, for example, by separately placing a new frame on the frame after the dicing, and sticking the divided semiconductor wafers (all the diced chips) to the adhesive tape. If the adhesive tape of the previously attached frame is peeled off, it is possible to easily replace the chip with a new frame with the back surface of each chip facing upward. The back surface of the wafer after dicing, that is, the chip, may be polished individually one by one, but it is preferable to simultaneously polish a plurality of chips in order to increase productivity.

The chip replacement operation can be performed by using an appropriate jig. For example, FIG. 5 shows an example of such a case, in which a storage hole 8a for fitting the chip 4 to the upper surface of the substrate 8 is provided. A large number of them are arranged side by side at predetermined intervals,
As shown in FIG. 6, a plurality of suction holes 8b penetrate the bottom surface of the substrate 8 and are juxtaposed on the bottom surface of the substrate a. These suction holes 8b communicate with suction holes (not shown) of the chuck table 1. Configuration. Therefore, the diced chip 4 is fitted into each of the storage holes 8a with its back surface 4a facing upward, and the suction holes of the chuck table 1 and the suction holes 8 of the substrate 8 are formed.
By suction through b, the chip 4 can be fixed. At this time, the fixed chip 4 is made to protrude from the upper surface of the substrate 8 for a polishing process. Further, the chip may be frozen and fixed to the substrate 8 with water or the like in order to further increase the fixing force.

After the chip 4 is fixed by using the jig 9 in this manner, a polishing process is performed by the polishing grindstone 6 in the same manner as described above, and the back surface 4a of the chip 4 is polished and finished to a predetermined thickness. it can.

[0015]

As described above, according to the present invention,
Since the semiconductor wafer is first diced and divided into chips, and then polished with the back side of the chip facing up, there is no need to dice after polishing a large semiconductor wafer thinly. Excellent effects such as prevention of damage such as chipping can be prevented and chip backside chipping can be prevented.

[Brief description of the drawings]

FIG. 1 is an explanatory view of a polishing step showing one embodiment of the present invention.

FIG. 2 is a plan view showing a state where the semiconductor wafer is attached to an adhesive tape of a frame after dicing.

FIG. 3 is a perspective view showing a state in which chipping has occurred on the back surface of the chip after dicing.

FIG. 4 is a perspective view showing a state where chipping has disappeared by polishing the back surface of the chip.

FIG. 5 is a perspective view showing an embodiment of a jig for fixing a chip.

FIG. 6 is an explanatory diagram showing a use state of the jig.

[Explanation of symbols]

1. Chuck table 2. Semiconductor wafer 3.
Frame 4 Chip 4a Back surface 4b Chipping 5 Adhesive tape 6 Polishing grindstone 7 Polishing device 8 Substrate 8a Storage hole 8b
Suction hole 9 ... Jig

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H01L 21/78 H01L 21/304

Claims (1)

(57) [Claims] 1. A method for dividing a semiconductor wafer into chips, comprising: a step of dicing the semiconductor wafer prior to polishing the back surface of the semiconductor wafer; and a step of: A method for dividing a semiconductor wafer, comprising: a step of housing the chip with the back surface facing upward; and a step of polishing the back surface of the chip fixed to the substrate.