JPH08316174A - Method of cutting semiconductor wafer having glass - Google Patents

Abstract

PURPOSE: To reduce the change of the electric characteristics of a semiconductor element at trimming and after cutting. CONSTITUTION: Prior to trimming of a semiconductor wafer 1 having a glass which is held by a vacuum chuck, a Si wafer 10 between semiconductor pressure sensors A is cut to form a groove 12 and glass 20 is cut along the groove 12 to form a first groove 22. By forming these grooves the rigidity of the wafer 1 can be low whereby the wafer 1 is little restored to an original warped condition even when it is released from a vacuum chuck table after trimming. Thus, the deviation of the sensor A settled at trimming from its working origin can be reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for cutting a glass-bonded semiconductor wafer into a plurality of semiconductor elements.

[0002]

2. Description of the Related Art As a method of cutting a semiconductor wafer in which a semiconductor is bonded to an insulator, there is a method described in JP-B-63-36154. This is to cut a semiconductor with a semiconductor strain gauge chip adhered and fixed on glass into a plurality of semiconductor pressure sensors, cut the semiconductor with a blade, and then cut it with a blade By cutting the glass with a blade having a coarse grain size, the semiconductor is prevented from chipping during the cutting.

[0003]

By the way, it is known that the above semiconductor wafer is slightly warped during the manufacturing process thereof. When the semiconductor wafer having the warp is vacuum-chucked to the vacuum chuck table, the warp is corrected by the suction force and becomes flat.

Therefore, the vacuum-chucked semiconductor wafer is in a state in which a stress for restoring the original warped state is inherent. Therefore, when the semiconductor wafer is trimmed while the stress is present and the semiconductor wafer is removed from the vacuum chuck table, the semiconductor wafer is restored to the original warped state due to the stress.

Therefore, the warp causes distortion in the trimming interval when the above trimming is performed,
Since the operation origin of the semiconductor pressure sensor is deviated, there is a problem that an error occurs in electrical characteristics such as sensitivity of the sensor.
Therefore, it is an object of the present invention to reduce the error in the electrical characteristics of a semiconductor element by reducing the warpage that occurs in the semiconductor wafer when the semiconductor wafer is released from the vacuum chuck state.

[0006]

In order to achieve the above object, the present invention provides a glass (2
0) The semiconductor wafer with glass (1) to which the semiconductor wafer (10) is bonded is vacuum-chucked to a vacuum chuck table, the vacuum-chucked semiconductor wafer with glass (1) is trimmed, and then a plurality of wafers are attached. A method of cutting a semiconductor wafer with a glass for cutting into a semiconductor element (A), the semiconductor wafer (1) having the glass bonded thereto.
Of the glass (2) from a predetermined position on the semiconductor wafer (10) before vacuum chucking the wafer onto the vacuum chuck table.
The technical means of having a step of forming the grooves (12, 22) toward the inside of (0) is adopted.

In the invention according to claim 2, the glass (2
0) the semiconductor wafer (10) is bonded onto the glass-attached semiconductor wafer (1) to a boundary between the semiconductor wafer (10) and the glass (20) to a first groove (1).
2) forming the first groove (1)
2) from the step of forming a second groove (22) narrower than the first groove (12) toward the inside of the glass (20), and the step of forming the second groove (22). A step (500, 600) of vacuum-chucking the formed semiconductor wafer with glass (1) on a vacuum chuck table to trim the semiconductor wafer; and a plurality of semiconductor wafers (1) with glass having been trimmed. The technical means of including a step (900) of cutting the semiconductor element (A).

According to a third aspect of the present invention, in the method of cutting a semiconductor wafer with glass according to the second aspect, the step (900) of cutting into a plurality of semiconductor elements (A) comprises:
A technical means of cutting the trimmed glass-equipped semiconductor wafer (1) into a plurality of semiconductor elements (A) with a blade having a thickness wider than the width of the second groove (22) is adopted.

According to a fourth aspect of the invention, in the method of cutting a glass-equipped semiconductor wafer according to the first or second aspect, after the trimming (500, 600) is performed, the inside of the glass (20) is Groove (22, 24)
The technical means is adopted which includes a step (900) of forming a groove (26) in the glass (20) which communicates with the groove (22, 24) from a direction opposite to the forming direction of the glass.

The reference numerals in parentheses of the above-mentioned means indicate the correspondence with the concrete means described in the embodiments described later.

[0011]

The effect of restoring the warped state of the glass-equipped semiconductor wafer increases in proportion to the magnitude of the rigidity of the glass-equipped semiconductor wafer. Therefore, if the rigidity of the semiconductor wafer with glass is reduced, the restoring force can be reduced.

Therefore, according to the first to fourth aspects of the invention, since the groove is formed from a predetermined position on the glass-equipped semiconductor wafer toward the inside of the glass, the rigidity of the glass-equipped semiconductor wafer is reduced. be able to. Since the groove is formed before the semiconductor wafer with glass is vacuum-chucked to the vacuum chuck table and trimming is performed, even if the semiconductor wafer with glass is removed from the vacuum chuck table, the original warped state is restored. The amount can be reduced.

Therefore, since distortion such as a trimming interval when trimming in a vacuum chuck state can be reduced, it is possible to reduce the amount of change in electrical characteristics set during trimming after cutting. In particular,
According to the invention described in claim 2, since there is a step of forming a second groove having a width narrower than the groove from the groove formed toward the inside of the glass toward the inside of the glass,
According to the invention as set forth in claim 4, there is a step of forming a groove communicating with the groove in the glass from a direction opposite to a forming direction of the groove formed toward the inside of the glass. In addition to the effect, it is possible to prevent chipping from occurring in the groove forming portion of the semiconductor wafer.

When cutting the glass in which the second groove is formed, it is conceivable to cut the glass from the second groove with a blade having the same width as the second groove. Is difficult to see because it is formed at a position deeper than the groove formed in the semiconductor wafer, and thus it is difficult to align the blade with the corner of the second groove. However, according to the third aspect of the present invention, since the glass is cut by the blade having the thickness wider than the width of the second groove, the alignment of the groove formed on the semiconductor wafer with the corner is performed. It becomes possible and the glass can be easily cut.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of a semiconductor element cutting method (hereinafter referred to as a cutting method) of the present invention will be described below with reference to the drawings. In each of the following embodiments, a method of cutting a semiconductor pressure sensor will be described as an example of a semiconductor element.
FIG. 1A is a partial cross-sectional view of the glass-equipped semiconductor wafer 1 showing a state where the first groove 12 and the second groove 22 are formed at the boundary portion between the semiconductor pressure sensors A of the semiconductor wafer 1 with glass. 1B is a partial cross-sectional view of the glass-equipped semiconductor wafer 1 in which the cutting of the glass 20 is completed, and FIG.
FIG. 3B is a plan view and FIG. 3 is a process diagram showing a cutting process.

First, the structure of a glass-equipped semiconductor wafer 1 in a wafer state (a state in which it is not separated into individual semiconductor pressure sensors A) will be described with reference to FIG. FIG. 1 (a)
As shown in FIG. 3, a silicon wafer 10 as a semiconductor wafer constituting the glass-equipped semiconductor wafer 1 has a glass 20
Is bonded to the surface of the aluminum plate by anodic bonding. It should be noted that the glass semiconductor wafer 1 is slightly warped during the manufacturing process. Further, in this example, the glass 20
Is formed of borosilicate glass (for example, trade name Pyrex glass).

A diaphragm 11 is formed on the surface of the silicon wafer 10. A space 27 is formed in the silicon wafer 10 below the diaphragm 11, and a pressure introducing hole 21 that penetrates the glass 20 in the vertical direction and communicates with the space 27 is formed in the glass 20. In this embodiment, the silicon wafer 10 has a thickness of 0.3 m.
m, and the thickness of the glass 20 is 3.0 mm.

Next, a method of cutting the above-mentioned glass-equipped semiconductor wafer 1 by the cutting method of the present invention will be described with reference to FIGS.
Will be described with reference to. First, the tape 30 is attached to the bottom surface of the glass 20 of the semiconductor wafer with glass 1 to fix the semiconductor wafer with glass 1 to the dicing device (step 100). Subsequently, the silicon wafer 10 is cut along the scribe line 17 in FIG. 2 with a blade for cutting silicon to a depth of 0.3 mm at a feed rate of 10 mm / sec (step 200). The first groove formed by the cutting is shown at 12 in FIG.

In the present embodiment, the thickness (blade width) of the silicon cutting blade is 210 μm, and the grain size is 2000 to 3000, which is finer than that for glass cutting in order to prevent chipping of the cut surface. To use. Next, the first glass cutting blade is placed in the center of the cutting portion 12 so that the distances from the corners 15 on both sides of the first groove 12 are equal, and the glass 20 is deeply fed at a feeding speed of 4 mm / sec. Cut to 2.0 mm (step 300). The second groove formed by the cutting is shown at 22 in FIG.

By forming the first groove 12 and the second groove 22 as described above, the semiconductor wafer with glass 1
The rigidity of the can be reduced. In particular, the glass 20 is harder and has a higher rigidity than the silicon wafer 10,
By forming the second groove 22 in the glass 20, the rigidity of the glass-equipped semiconductor wafer 1 can be effectively reduced.

The thickness and cutting depth of the blade are taken into consideration in consideration of the durability of the blade (maximum cutting depth / 20) .ltoreq.
Since there is a constraint of (blade thickness), in this embodiment, a thickness of 11 satisfying 2.0 mm / 20 = 100 μm.
A glass cutting blade having a particle size of 600 to 1000 and a diameter of 0 μm is used. Next, the tape 30 attached to the bottom surface of the glass-equipped semiconductor wafer 1 is peeled off (step 400), and the bottom surface of the glass-equipped semiconductor wafer 1 is vacuum chucked on the vacuum chuck table of the trimming device (step 500).

Then, the surface of the silicon wafer 10 is trimmed (step 600), and the semiconductor wafer with glass 1 is reset from the trimming device (step 700).
Then, the tape 31 is attached to the bottom surface of the semiconductor wafer with glass 1.
Is attached (step 800). Next, the remaining portion of the glass 20 (second groove 2
2) is cut (step 900).

Here, it is conceivable to use the same blade as the first glass cutting blade as the second glass cutting blade, but the first glass cutting blade has a thickness of 110 μm. Since it is thin and the distance from both side surfaces of the blade to the corner portion 15 is long, it is difficult to position the blade at the center of the cutting portion 12 with the corner portion 15 as a reference. In addition, the corner portion 16 of the second groove 22,
Since 16 is located one step lower than the silicon wafer 10 and is hidden by the blade and is hard to see, it is difficult to cut the bottom of the second groove 22 by aligning the tip of the blade with the corners 16 and 16. .

Therefore, in this embodiment, as the second glass cutting blade, a blade having the same grain size as the first glass cutting blade and a thickness of 150 μm is used, and the second glass cutting blade is used. So that they can be aligned on the basis of the corners 15, 15. Then, the glass 20 is cut into the second groove 22 by the second glass cutting blade.
Cut in the form including. The third groove formed by the cutting is shown at 23 in FIG.

As described above, the cutting of the glass 20 by the second glass cutting blade is performed by the second glass cutting blade which has already been formed.
Since the cutting is performed in such a manner that the groove 22 is included, the load applied to the blade can be reduced as compared with the case where the second groove 22 is not formed. Moreover, since the pressing force acting on the side surface of the blade is small, the frictional heat generated in the blade can be reduced.

Therefore, the durability of the blade can be improved. Next, the semiconductor wafer 1 is removed from the dicing device, the tape 31 is peeled off, and the semiconductor pressure sensors A are individually separated (step 1000). FIG. 4 shows FIG.
FIG. 6 is a characteristic diagram showing the relationship between the cutting depth t of the semiconductor wafer with glass 1 shown in FIG. As shown in the figure, the sensitivity error decreases as the cutting depth t increases, and the sensitivity error is greatly improved at t = 2.0 mm (cutting depth of the glass 20 is 1.7 mm). That is, the sensitivity error of the semiconductor pressure sensor A can be reduced by cutting the silicon wafer 10 and the glass 20 by a predetermined depth to form a groove before trimming as described above.

Next, a second embodiment of the present invention will be described with reference to FIG. In the cutting method of this embodiment, the first cutting of the glass 20 is performed wider than that of the first embodiment,
The second cutting is performed with a width narrower than the first cutting width. First of all, silicon wafer 1
0 is cut with a blade having a thickness of 270 μm. Subsequently, the glass 20 is cut with a blade having a thickness of 210 μm using the corner portion 15 of the first groove 121 formed by the cutting as a positioning guide. Subsequently, the second cutting of the glass 20 is performed with a blade (thickness is 150 μm) thinner (narrower in blade width) than the blade used for the first cutting.

At this time, the positioning of the blade is difficult because it is difficult to obtain accuracy because the gap between the corners 15 is large when the corners 15 are used as a reference. Therefore, the first glass formed by cutting the glass 20 for the first time is used. The corner 16 of the groove 24 is used as a reference. The positioning of the blade in this case is different from the case of the first embodiment described above in that the corner portion 1 is larger than the thickness (150 μm) of the blade.
Since the distance between 6 and 16 is wider, the corner portion 16 is not hidden by the blade and the positioning is not difficult.

According to the cutting method of the second embodiment as well, the stress inherent in the silicon wafer 10 and the glass 20 is cut by cutting the silicon wafer 10 and the glass 20 before trimming as in the first embodiment. Since it is possible to eliminate the influence of, it is possible to manufacture a semiconductor pressure sensor with a small sensitivity error. Further, since the cooling liquid can be injected into the gap formed between both side surfaces of the blade and the inner wall surface 24a of the first groove 24, the cooling efficiency of the blade can be improved as compared with the case where there is no gap. it can.

Next, a third embodiment of the present invention will be described with reference to FIG. The present embodiment is characterized in that the second cutting of the glass 20 is performed from the bottom surface of the glass 20. First,
The silicon wafer 10 is thinner than the blade for cutting silicon used in the first embodiment (thickness 170 μm).
Cut at m). The cutting portion is indicated by 122 in FIG. Then, from the center of the cutting portion 122, the first glass cutting blade (thickness 110 μm) was used to cut the glass 20 to a depth of 2.0 m.
Cut to m. The first groove formed by the cutting is indicated by 22 in FIG. Then, the tape 30 is peeled off, the wafer 1 is vacuum-chucked to the vacuum chuck table, and the silicon wafer 10 is trimmed.

Next, the tape 30 is placed on the silicon wafer 10.
And the silicon wafer 10 side is attached to a dicing device, and the glass 20 is cut from the bottom of the glass 20 with a second glass cutting blade (thickness 170 μm) to a depth of 1.5 mm.
Disconnect. That is, the second groove that communicates with the first groove 22.
The glass 20 is cut by cutting with the second blade for cutting glass so that the groove 26 is formed.

As described above, according to this embodiment, since the second cutting of the glass 20 is performed from the bottom surface of the glass 20, the width of the groove 122 formed in the first silicon wafer 10 is set to the above first and second widths. It can be made narrower than the cutting width of the second embodiment. Therefore, since the distance D between the scribe lines 17 can be reduced by the amount that can be narrowed, more semiconductor pressure sensors A can be taken from the semiconductor wafer 1 than in the cutting methods of the first and second embodiments. it can.

The type of blade in each of the above embodiments is not limited as long as it is for silicon or glass, and the particle size is not limited to the above. Further, the cutting method of each of the above-described embodiments can be applied even if the material of the glass 20 is other than Pyrex, and the same effect can be obtained in that case. further,
The tapes 30 and 31 may be of the same type, or UV tape or the like may be used to facilitate peeling.

[Brief description of drawings]

FIG. 1 (a) shows a cutting method according to a first embodiment of the present invention.
FIG. 3 is a partial cross-sectional view of the glass-equipped semiconductor wafer 1 in which grooves are formed from the silicon wafer 10 toward the glass 20.
(B) is a partial cross-sectional view of the glass-equipped semiconductor wafer 1 showing a state in which the glass 20 is cut.

FIG. 2 is an explanatory plan view of FIG. 1 (b).

FIG. 3 is a process drawing of the cutting method of the present invention.

4 is a characteristic diagram showing the relationship between the cutting depth of the semiconductor wafer with glass 1 and the sensitivity error of the semiconductor pressure sensor A. FIG.

FIG. 5 (a) shows the cutting method according to the second embodiment of the present invention.
FIG. 3 is a partial cross-sectional view of the glass-equipped semiconductor wafer 1 in which grooves are formed from the silicon wafer 10 toward the glass 20.
(B) is a partial cross-sectional view of the glass-equipped semiconductor wafer 1 showing a state in which the glass 20 is cut.

FIG. 6 (a) shows a cutting method according to a third embodiment of the present invention.
FIG. 3 is a partial cross-sectional view of the glass-equipped semiconductor wafer 1 in which grooves are formed from the silicon wafer 10 toward the glass 20.
(B) is a partial cross-sectional view of the glass-equipped semiconductor wafer 1 showing a state in which the glass 20 is cut.

[Explanation of symbols]

1 ... Semiconductor wafer with glass, 10 ... Silicon wafer, 11 ... Diaphragm, 20 ... Glass, 21 ...
Pressure introducing hole, 12, 121, 122 ... Groove, 22, 24
..First grooves, 23, 25, 26 ... Second grooves, 27 ..
・ Cavity, 30, 31 ・ ・ Tape, A ・ ・ Semiconductor pressure sensor

Claims (4)

[Claims] 1. A semiconductor wafer with glass in which a semiconductor wafer is bonded onto glass is vacuum-chucked to a vacuum chuck table, the vacuum-chucked semiconductor wafer with glass is trimmed, and then cut into a plurality of semiconductor elements. A method of cutting a semiconductor wafer with glass, which comprises forming a groove from a predetermined position on the semiconductor wafer toward the inside of the glass before vacuum chucking the semiconductor wafer bonded with the glass on a vacuum chuck table. A method of cutting a glass-equipped semiconductor wafer, comprising: 2. A step of forming a first groove from a predetermined position on a glass-equipped semiconductor wafer in which a semiconductor wafer is bonded onto glass to a boundary between the semiconductor wafer and glass, and the step of forming the first groove from the first groove. Forming a second groove having a width narrower than that of the first groove toward the inside of the glass; and vacuum chucking the glass-equipped semiconductor wafer having the second groove on a vacuum chuck table to form the semiconductor wafer. And a step of cutting the trimmed glass-equipped semiconductor wafer into a plurality of semiconductor elements. 3. The step of cutting into a plurality of semiconductor elements comprises cutting the trimmed glass-coated semiconductor wafer into a plurality of semiconductor elements with a blade having a thickness wider than the width of the second groove. The method for cutting a glass-equipped semiconductor wafer according to claim 2, wherein. 4. A step of forming a groove communicating with the groove in the glass from a direction opposite to a forming direction of the groove formed toward the inside of the glass after the trimming is performed. The method for cutting a semiconductor wafer with glass according to claim 1 or 2.