JPS61249709A - Method of cutting semiconductor wafer - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Background and Objects of the Invention] The present invention relates to an improvement in a method for cutting a semiconductor wafer into chips for forming semiconductor elements.

In general, semiconductor devices are manufactured by taking care not to cause distortion or scratches on the device itself in order to effectively utilize its device characteristics.
Cutting, processing, etc. Particularly, in the case of light emitting elements such as compound semiconductors, the material is brittle and easily susceptible to dislocations, defects, etc., and therefore a great deal of care is taken in processing the elements.

Conventionally, when chipping an element such as a light emitting diode made of a compound semiconductor such as Q, aP, G8AS, QaAsP, etc., (1) (100) is diced parallel to or almost parallel to the <110> direction. (2) (10
0) 45 degrees or approximately 4 degrees to the <110> direction using a plane
Cut at a 5 degree angle. Alternatively, (3) a method such as cutting down to the tape to which the wafer is attached has been taken. These conventional methods will be explained below with reference to FIGS. 3 to 5. Figure 3 shows dicing in the <110> direction (
There is a schematic diagram of chipping the 100) surface. jQ>direction-
゛This is a schematic diagram of dicing into chips, (-1')
(0) is a plan view, (0) is a π (clear diagram) where 1 royal force is applied from below and a cut is made to form a chip. A plan view, and (b) a side view.

In the figure, ] is (100) the substrate, 2 is the adhesive tape that is the adhesive layer, 3 is the pressure rod, 4 is the crack, 5 is the chipping 1.6 is the clogging groove, 7 is the adhesive, 9 is the cutting groove, 10 is a cleavage plane. In the case of (1), as shown in Fig. 3, the deeper the cutting groove and the faster the cutting speed, the more the chipping
It is easy to occur. In the case of (2), if the element is made into a chip by applying from the bottom surface of the sheet (adhesive tape 2) in FIG.
Since the marks 5 are tilted, there are many cracks along the cleavage 10, which causes the desired element to deviate from its original cubic shape.

Furthermore, the crack 4 tends to become a progressive crack 4 that penetrates into the main body of the device. In the case of (3), in FIG. 5, the dicing blade winds up the adhesive tape and cuts the wafer when the cutting force is gone, causing chipping 5 and creating shell-like unevenness at the cut end. This size ranges from 10 .mu.m to 50 .mu.m in some cases, and seriously impairs the surface shape and characteristics of the element.

The present invention was made in view of the above situation, and includes cutting,
The object of the present invention is to provide a method for cutting a semiconductor wafer with a flat surface, less chipping, less adverse effects on device characteristics such as light emitting characteristics, and high quality cutting.

[Summary of the Invention] The method for cutting a semiconductor wafer of the present invention is such that when cutting a semiconductor chip by cutting a cutting groove from a semiconductor wafer formed on an adhesive layer using a cutting tool, the method cuts the semiconductor wafer to a depth just before reaching the adhesive layer. This is a method of cutting by inserting the above-mentioned cutting grooves, leaving an uncut layer that can be inserted by the crank and cut away. That is, when cutting a semiconductor wafer with a dicing saw, do not cut to the adhesive layer (adhesive tape), but cut to just before the adhesive layer - to prevent the C-chip from cutting into the tape or adhesive layer, In addition to preventing clogging of the plate due to adhesive, since the plate is almost completely cut, deviation from the cubic shape due to cleavage can be almost eliminated.

[Example] The semiconductor wafer cutting method of the present invention will be described below using an example, and the conventional method will be described with reference to FIG. Figure 1 is <11
This is a schematic diagram showing the situation when a GaAs crystal is diced in the (100) direction. (() is a plan view, ((0)
) is an explanatory cross-sectional view, (/ is an enlarged view. In the figure,
The number of revolutions of the blade is 1'0.000r'l)m, the cutting speed is 2 M/S, and the uncut dimension of the uncut layer 8 is about 10 μm from the adhesive tape 2. After cutting, when removing the adhesive tape from the adhesive tape (/9), a crack 4 (indicated by the broken line of /9) was generated along the cleavage at the time of cutting, and each chip could be separated without any damage. In other words, the bottom of the chip It is cut at almost right angles due to directional cracks, and there is no clogging caused by adhesive tape or adhesive, etc.
There is little chipping 5 and almost no deviation in shape due to cleavage occurs. The above example is 1 when the adhesive layer is an adhesive tape.
Although I mentioned ζ, the same applies to adhesives.

In this way, the semiconductor wafer cutting method of this embodiment is such that when a semiconductor chip is cut by cutting grooves, a crack occurs at a depth just before reaching the adhesive layer, leaving an uncut layer that can be separated. Since cutting grooves are provided, the cut surface is flat and there is little chipping. It is now possible to use patterns around the chip, which was difficult in the past, ensuring a lean pattern area and eliminating the occurrence of burrs, which adversely affect device characteristics. 1q can have good quality with less impact.

In the above embodiment, the case of GaAs was described, but Si
It can be applied to the cutting and analysis of materials with strong cleavage properties, such as semiconductor crystals such as , Ge, other compound semiconductors, and ionic bonding substances.

Figure 2 is an example of Sen, and is a schematic diagram of the situation where it is cut in the <100> direction tilted 45 degrees from the <110> direction (-1').
is a plan view, ([]) is a cutting diagram, (/→ is an enlarged view - (
"Yes. Tilt 45 degrees to the incision normal, <110>
There are 4 cracks along the direction of the separation.This dimension is 5μ
At m, the chips propagated in a direction where no blemish was left due to the cutting stress, and by removing the chip from the adhesive tape 2, the chip could be completely separated. Further, when the uncut layer 8 was closed by 10 μm, the displacement of the cube due to cleavage could be suppressed to 5 μm or less. These vary depending on the physical properties of the semiconductor, such as surface orientation, cleavage direction, cleavage hardness, brittleness, etc., and it is necessary to determine an appropriate cutting speed and uncut allowance depending on the material. This example also has the same effects as the above example.

[Effects of the Invention] As described above, the method for cutting a semiconductor wafer of the present invention has the effect that the cut surface is flat and the wafer can be cut into a crystalline material with good properties without chipping or burrs. .

[Brief explanation of drawings]

FIG. 1 and FIG. 2 are schematic diagrams of chipping by the semiconductor wafer cutting method of the present invention, respectively.
The figure shows dicing in the <110> direction, and Fig. 2 shows dicing in the <100> direction, respectively. The figure is a schematic diagram of the process of making chips using the conventional method.
The figure shows dicing in the <110> direction, and Figure 4 shows dicing in the <:106> direction. A) is a plan view, and (b) is a cross-sectional explanatory view. 2...Adhesive tape, 4...Crack, 8...Uncut layer, 9...Cut groove. Agent Patent Attorney Fujio Sato 2nd hearing (a) u (O)- (l\) Figure 3 (a)

Claims (4)

[Claims] (1) In a method of cutting semiconductor chips by cutting grooves using a dicing saw from a semiconductor wafer formed on an adhesive layer, cracks may occur due to the cutting grooves being formed to a depth just before reaching the adhesive layer. A method for cutting a semiconductor wafer, comprising inserting and cutting the cutting layer while leaving an uncut layer that can be separated. (2) The uncut layer of the semiconductor wafer is 100 μm
A method for cutting a semiconductor wafer according to claim 1, which is as follows. (3) The method for cutting a semiconductor wafer according to claim 1, wherein the adhesive layer is an adhesive tape or an adhesive. (4) The method for cutting a semiconductor wafer according to claim 1, wherein the semiconductor wafer is silicon or a compound semiconductor.