TW201715697A - Method for manufacturing semiconductor device - Google Patents

Abstract

An embodiment of the present invention provides a method of manufacturing a semiconductor device that can easily produce a semiconductor device. A method of manufacturing a semiconductor device according to an embodiment includes a step of attaching a first support tape to a first surface of a semiconductor wafer; a step of singulating the semiconductor wafer into a plurality of semiconductor chips; a step of attaching the second support tape on the second surface of the plurality of semiconductor chips along the first direction; a step of peeling off the first support tape from the plurality of semiconductor chips; and a step of enlarging a distance between the semiconductor chips by extending the second support band; a ratio of a nominal stress generated by elongation of the second semiconductor support band relative to the first direction to a nominal stress generated by elongation relative to the second direction is 0.7 to 1.4.

Description

Semiconductor device manufacturing method [Related application]

This application is based on the priority of the application based on Japanese Patent Application No. 2015-78578 (application date: April 7, 2015) and Japanese Patent Application No. 2016-27371 (application date: February 16, 2016). right. This application contains the entire contents of the basic application by reference to the same basic application.

Embodiments of the present invention relate to a method of fabricating a semiconductor device.

The wafer is singulated into a semiconductor wafer and then processed in the support strip.

Embodiments of the present invention provide a method of manufacturing a semiconductor device in which wafer singulation can be stably performed.

A method of manufacturing a semiconductor device according to an embodiment includes: a step of attaching a first support tape to a first surface of a semiconductor wafer; a step of singulating the semiconductor wafer into a plurality of semiconductor wafers; and a second support strip a step of attaching the first direction to the second surface of the plurality of semiconductor wafers; a step of stripping the first support strip from the plurality of semiconductor wafers; and expanding the semiconductor wafer by extending the second support strip The step of the distance; the ratio of the nominal stress generated by the elongation of the second semiconductor support strip relative to the first direction to the nominal stress generated by the elongation with respect to the second direction is 0.7 to 1.4.

10‧‧‧Semiconductor wafer

10a‧‧‧ first side

10b‧‧‧ second side

20‧‧‧Cutting Blade

30‧‧‧ blade slot

40‧‧‧roll

50‧‧‧First support belt

60‧‧‧grinding grindstone

80‧‧‧Semiconductor wafer

80a‧‧‧ first side

80b‧‧‧ second side

85‧‧‧ wafer

90‧‧‧ rate

100‧‧‧second support belt

110‧‧‧Support ring

115‧‧‧roll

117‧‧‧ motor

120‧‧‧ fixture

140‧‧‧Adsorption chuck

150‧‧‧ picking institutions

200‧‧‧DAF

210‧‧‧Adhesive layer

220‧‧‧Substrate layer

310‧‧‧Laser

320‧‧‧Modified area

330‧‧‧ crack

500‧‧‧ bracket

510‧‧‧With

A‧‧‧ area

B‧‧‧Area

D‧‧‧Distance

D1‧‧‧ distance

D2‧‧‧ distance

D3‧‧‧ distance

D4‧‧‧ distance

H‧‧‧Extension

S1‧‧‧ area

S2‧‧‧ area

S3‧‧‧ area

W1‧‧‧Width

W2‧‧‧Width

X‧‧‧ direction

Y‧‧‧ direction

Fig. 1 is a schematic perspective view showing a method of manufacturing the semiconductor device of the first embodiment.

Fig. 2 is a schematic cross-sectional view showing a method of manufacturing the semiconductor device of the first embodiment.

Fig. 3 is a schematic perspective view showing a method of manufacturing the semiconductor device of the first embodiment.

Fig. 4 is a schematic cross-sectional view showing a method of manufacturing the semiconductor device of the first embodiment.

Fig. 5 is a schematic perspective view showing a method of manufacturing the semiconductor device of the first embodiment.

Fig. 6 is a schematic cross-sectional view showing a method of manufacturing the semiconductor device of the first embodiment.

Fig. 7 is a schematic perspective view showing a method of manufacturing the semiconductor device of the first embodiment.

Fig. 8 is a schematic cross-sectional view showing a method of manufacturing the semiconductor device of the first embodiment.

Fig. 9 is a schematic perspective view showing a method of manufacturing the semiconductor device of the first embodiment.

Fig. 10 is a schematic cross-sectional view showing a method of manufacturing the semiconductor device of the first embodiment.

Fig. 11 is a schematic perspective view showing a method of manufacturing the semiconductor device of the first embodiment.

Fig. 12 is a schematic cross-sectional view showing a method of manufacturing the semiconductor device of the first embodiment.

Figure 13 is a schematic cross-sectional view showing the method of manufacturing the semiconductor device of the first embodiment; view.

Fig. 14 is a schematic cross-sectional view showing a method of manufacturing the semiconductor device of the first embodiment.

15(A) is an enlarged view of the S1 region of FIG. 12, and is a schematic cross-sectional view showing the second support strip 100 and the semiconductor wafer 80 before expansion, and FIG. 15(B) is an enlarged view of the S2 region of FIG. Also, a schematic cross-sectional view of the expanded second support tape 100 and the semiconductor wafer 80 is shown.

Fig. 16(A) is a schematic cross-sectional view showing a DAF (Die Attach Film) peeling failure, and Fig. 16(B) is a schematic cross-sectional view showing a DAF cutting failure.

Fig. 17(A) is a schematic diagram showing the relationship between the nominal strain of the second support zone and the nominal stress in the case where the elongation at the time of the nominal strain is small, and Fig. 17(B) shows the nominal A pattern of the relationship between the nominal strain of the second support zone and the nominal stress in the case of a large elongation at the time of strain in the strain.

Fig. 18 is a graph showing the results obtained by measuring the extended distance D between the examples in which the elongation at the time of the fall of the second support zone in the nominal strain is different.

Fig. 19(A) is a schematic diagram showing the relationship between the nominal strain and the nominal stress of the second support zone when the anisotropy is large, and Fig. 19(B) shows the case where the anisotropy is small. A schematic chart of the relationship between the nominal strain and the nominal stress of the second support zone.

20(A) is a plan view of the upper surface of the semiconductor wafer 80 after expansion, and FIG. 20(B) is an enlarged view of the S3 area of FIG. 20(A) when the anisotropy is large, FIG. 20 (C) An enlarged view of the S3 region in Fig. 20(A) in the case where the anisotropy is small.

Fig. 21 is a graph showing the results obtained by measuring the extended distance D between the examples and the comparative examples in which the ratio of the nominal stress in the X direction to the Y direction of the second support band is different.

Fig. 22 is a graph showing the relationship between the nominal strain of the X-direction belt of the second support belt and the DAF cut-off rate.

Figure 23 is a view showing the measurement of the second support band of Comparative Example 1, Comparative Example 2, and Example The results of the results of the nominal strain, distance D, and DAF cut defects at the time of attachment.

24 to 28 are schematic perspective views for explaining a method of manufacturing the semiconductor device of the first embodiment.

Figures 29(a)-(c) are schematic diagrams illustrating nominal strain/nominal stress, true strain/true stress.

Fig. 30(a) is a graph showing the relationship between the nominal strain and the nominal stress in a sample, and Fig. 30(b) is a graph showing the relationship between the true strain and the true stress in the same sample.

Figure 31 is a summary of the evaluation results of DAF cut defects for a plurality of samples, the nominal strain, the elongation at the time of the nominal stress, the nominal strain at the time of the fracture using the true stress, or the true strain. table.

Hereinafter, embodiments will be described with reference to the drawings. In the following description, the same functions and constituent elements are denoted by the same reference numerals.

In the present specification and the drawings, even when the semiconductor wafer 10 is singulated into the semiconductor wafer 80 and the defective wafer 85, and the shape of the wafer is substantially maintained by a tape or the like, and the shape of the wafer is substantially maintained. It is sometimes described as the semiconductor wafer 10.

(Method of Manufacturing Semiconductor Device According to First Embodiment)

1 to 14 are views for explaining a method of manufacturing the semiconductor device of the first embodiment.

As shown in FIGS. 1 and 2, the semiconductor wafer 10 is diced.

The semiconductor wafer 10 has a first surface 10a and a second surface 10b. The first surface 10a is formed with an element surface of a NAND (Not AND) element, a transistor, a wiring, or the like (not shown). The second surface 10b is a surface opposite to the first surface 10a.

As shown in FIGS. 1 and 2, the blade groove 30 is formed on the first surface 10a of the semiconductor wafer 10 using the dicing blade 20. The blade grooves 30 are provided, for example, in a lattice shape. The blade slot 30 is formed to be The thickness of the semiconductor wafer 10 is shallow.

As shown in FIGS. 3 and 4, the first support tape 50 is attached to the first surface 10a. The first support belt 50 is, for example, a back grinding belt. The first support belt 50 is attached to the first surface 10a using the roller 40.

As shown in FIGS. 5 and 6, the second surface 10b is polished using the grindstone 60.

The second face 10b is approached to the first face 10a by grinding. Moreover, the second face 10b is in contact with the insert pocket 30. In this way, the insert pocket 30 penetrates the first surface 10a and the second surface 10b. Further, the semiconductor wafer 10 is singulated into a plurality of semiconductor wafers 80 and defective wafers 85 by the blade grooves 30. The semiconductor wafer 80 and the defective wafer 85 are maintained in a state of being attached to the first support tape, and thus are not discrete.

Furthermore, the semiconductor wafer 80 refers to a wafer that is shipped as a product of a semiconductor device, and the defective wafer 85 refers to a wafer that is not shipped as a product of a semiconductor device. The number of semiconductor wafers 10 divided into semiconductor wafers 80 or defective wafers 85 is arbitrary.

Similarly to the semiconductor wafer 10, the semiconductor wafer 80 has a first surface 80a and a second surface 80b. The first surface 80a is formed with an element surface of a NAND element, a transistor, a wiring, or the like (not shown). The first side 80a is attached to the face of the first support belt 50. The second surface 80b is a surface opposite to the first surface 80a.

In the following description, the defective wafer 85 may be processed in the same manner as the semiconductor wafer 80. Therefore, the description of the defective wafer 85 is omitted except where necessary.

As shown in FIGS. 7 and 8, the second support tape 100 is attached to the second surface 80b of the semiconductor wafer 80 and the support ring 110.

The semiconductor wafer 80 attached to the first support tape 50 is flipped upside down with the first support tape 50. The support ring 110 is disposed on the outer side of the plurality of semiconductor wafers 80. Further, the second support tape 100 is attached to the second surface 80b and the support ring 110 by using the roller 115.

The second support tape 100 is attached to the second surface 80b and the support ring 110, for example, in a state of being stretched using a motor 117 or the like. Because the second support belt 100 is stretched on one side Therefore, the second support tape 100 can be attached by narrowing the gap between the second support tape 100 and the second surface 80b, and between the second support tape 100 and the support ring 110.

Further, an arbitrary number of rolls or the like may be disposed between the roller 115 and the motor 117. The motor can be any type of motor. Further, even if it is not a motor, any mechanism can be used as long as the second support tape 100 can be stretched.

The direction in which the second support belt is carried out using the roller 115 is referred to as the X direction, and the direction orthogonal to the X direction is referred to as the Y direction. In other words, the relative advancement direction of the roller 115 with respect to the semiconductor wafer 80 is the X direction, and the extending direction of the roller 115 is the Y direction.

Furthermore, there is a case where the X direction coincides with the MD (Machine Direction) of the second support band. Further, there is a case where the Y direction coincides with the TD (Transverse Direction) of the second support band.

Regarding the second support belt 100, it will be described in detail below.

9 and 10 are schematic perspective views and cross-sectional views showing a state in which the second support tape 100 is attached to the second surface 80b and the support ring 110, and then turned upside down again.

9 and 10 show a state in which the second support tape 100 is cut by the lower surface of the support ring 110, but the invention is not limited thereto. For example, the second support strip 100 may be cut off by the outer side of the support ring 110 or may not be cut.

As shown in FIGS. 11 and 12, the first support tape 50 is peeled off from the semiconductor wafer 80. The semiconductor wafer 80 is attached to the second support tape 100. That is, the semiconductor wafer 80 is connected to the support ring 110 via the second support tape 100, so that the first support tape 50 can be peeled off from the semiconductor wafer 80.

As shown in FIG. 13, the second support belt 100 is elongated (expanded).

The semiconductor wafer 80 is pushed upward with respect to the support ring 110 using the jig 120. The length at which the second support tape 100 is pushed out is referred to as the amount of expansion H. By expanding the second support strip 100, the distance D between the singulated semiconductor wafers 80 is enlarged.

The method of elongating the second support strip 100 at the time of expansion will be described in more detail. Expansion At the time of exhibition, the second support tape 100 is attached to the support ring 110. And, the second support tape 100 is elongated by the jig 120. Next, since a frictional force is generated between the jig 120 and the second support belt 100, the stretcher is first supported by the region A between the support ring 110 and the jig 120.

If the area A is sufficiently elongated and the stress generated by the second support strip 100 is greater than the friction of the jig 120 and the second support strip, the area B below the semiconductor wafer 80 is elongated.

Therefore, for example, if the second support belt 100 is easily elongated, that is, the normal stress generated by the length of the second support belt (Normal Strain) is small, the area B is not easily Elongated. Conversely, if the second support strip 100 is not easily stretched, i.e., the nominal stress generated relative to the nominal strain is large, the region B is easily elongated.

As shown in FIG. 14, the semiconductor wafer 80 is, for example, a specific manufacturing step of a semiconductor device such as a step of mounting a substrate or other semiconductor wafer by picking up the pick-up mechanism 150 having the chuck 13 and transporting it to a substrate or other semiconductor wafer. Furthermore, when the semiconductor wafer 80 is picked up, it may be in a state in which a portion of the second support tape is attached. Further, specifically, the following DAF (not shown) may be picked up together with the semiconductor wafer 80.

(about the second support belt)

The second support belt 100 will be described in more detail with reference to FIGS. 15(A) and 15(B). 15(A) and 15(B) are schematic cross-sectional views showing the second support tape 100 and the semiconductor wafer 80 before and after expansion, respectively.

The second support tape 100 has, for example, a base material layer 220, an adhesive layer 210, and a DAF (Die Attach Film) 200.

The base material layer 220 contains, for example, a synthetic resin such as polyethylene terephthalate or polyolefin.

The adhesive layer 210 is bonded to any of the substrate layer 220 and the DAF 200. The adhesive layer 210 contains, for example, a synthetic resin such as an epoxy resin, a polyimide, an acrylic resin, a polyolefin, or an anthrone.

The DAF 200 includes, for example, an acrylic resin, a polyimide, or an epoxy resin.

As shown in FIG. 15(B), a portion of the second support tape 100 is cut for each of the semiconductor wafers by expansion. Specifically, the DAF 200 included in the second support zone is cut by expansion.

When the DAF is cut by the expansion, for example, DAF cut failure and DAF peeling failure may occur. This defect will be described using FIG. 16(A) and FIG. 16(B). 16(A) and 16(B) are views corresponding to an enlarged view of the S2 region of Fig. 13.

Fig. 16(A) is a schematic cross-sectional view showing a defect in DAF peeling. The DAF peeling failure is a defect in which the DAF 200 is peeled off from the adhesive layer 210. The position of the semiconductor wafer 80 and the DAF 200 is shifted and may be scattered as the case may be. Therefore, pickup of the semiconductor wafer 80 and the DAF 200 becomes difficult.

At the time of expansion, the semiconductor wafer 80 and the lower portion of the DAF 200 are stretched in a square shape due to the tension of the adhesive layer 210. Here, for example, when the amount of expansion H is large, the tension of the adhesive layer 210 is greater than the adhesion of the adhesive layer 210 to the DAF 200. When the tension is greater than the adhesion, the DAF 200 cannot adhere to the adhesive layer 210. That is, a DAF peeling failure as shown in Fig. 16(A) is generated.

This time, the relationship between the DAF peeling failure and the expansion amount H was confirmed by the applicant's experiment. Moreover, when the amount of expansion H is larger than 8 mm, DAF peeling failure particularly occurs remarkably. Further, when the adhesion between the DAF 200 and the adhesive layer 210 is 0.1 N/25 mm or more, it is preferable to prevent DAF peeling failure.

Fig. 16 (B) is a schematic cross-sectional view showing a defective DAF cut. The DAF cut-off defect is not sufficiently broken by the DAF200. Since the DAF 200 is followed by a plurality of semiconductor wafers 80, it is difficult to pick up the separated semiconductor wafer 80 together with the DAF 200.

In the case where the DAF cut is bad, since the DAF 200 is not cut, the distance D is not sufficiently enlarged. Therefore, by measuring the distance D, the DAF cut failure can be evaluated.

The DAF cut defect depends on the characteristics of the second support strip 100.

Hereinafter, the relationship between the DAF cut failure and the characteristics of the second support tape 100 will be further described.

First, the relationship between the elongation at break of the second support tape 100 and the DAF cut failure will be described.

17(A) and 17(B) are schematic diagrams showing the relationship between the nominal strain of the second support band 100 and the nominal stress. As shown in Fig. 17(A), if the second support band increases the nominal strain from 0%, the nominal stress decreases (falls and falls) at a point above a certain nominal strain. The point at which the nominal stress first drops is referred to as the point of undulation, and the nominal strain corresponding to the point of undulation is referred to as the elongation at the time of the fall. For example, in the embodiment of Fig. 17(B), the elongation at the time of the fall is larger than that of the comparative example of Fig. 17(A).

Fig. 18 is an experimental data obtained by plotting the relationship between the amount of expansion H and the distance D between the semiconductor wafers 80 in the examples and comparative examples in which the second support tape has different elongation at the time of the fall. In the present experiment, if the distance D is 40 μm or more, it means that the DAF is less defective. The data of Fig. 18 is measured data of about 50 points measured at 25 points in the X direction of the distance between different wafers and the distance in the Y direction.

As shown in Fig. 18, even in the comparative example in which the elongation was 40% at the time of the fall, the expansion amount H was set to 8 mm, and the DAF cutting failure could not be suppressed. In the comparative example in which the elongation at the time of lodging was 55%, the comparative example in which the elongation was 40% at the time of the fall was improved, but the DAF cut defect still occurred. On the other hand, in the sample in which the elongation at the time of the fall was 90%, the DAF cutting failure was largely suppressed by setting the expansion amount H to 8 mm. The reason is considered to be that, for example, the sample having a higher elongation at the time of the fall can be equally elongated without being affected by the difference of the second support tape 100 or the like.

Then, in order to further suppress the DAF cut failure, the relationship between the anisotropy of the nominal stress generated in the X direction and the Y direction of the second support tape 100 during expansion and the DAF cut failure will be described. The second support strip 100 is, for example, present in the manufacture of the second support strip 100. The reason is that the nominal stress generated in the X direction and the Y direction is different.

19(A) and 19(B) are schematic diagrams showing the relationship between the nominal strain of the second support band 100 and the nominal stress. In each graph, (a) shows the relationship of the X direction, and (b) shows the relationship of the Y direction. The ratio of the length of the nominal strain system to the length of the natural state when the natural state is set to 1.

In the comparative example of Fig. 19(A), when the nominal strain is e, the nominal stress in the X direction is approximately twice the nominal stress in the Y direction. On the other hand, in the embodiment of Fig. 19(B), when the nominal strain is e, the nominal stress in the X direction is approximately one times the nominal stress in the Y direction. That is, in the comparative example, the Y direction is more likely to be elongated than the X direction, whereas the difference between the ease of elongation in the Y direction and the X direction in the embodiment is small.

The state in which the second support band 100 of the comparative example and the embodiment is expanded will be described with reference to Figs. 20(A) to (C).

Fig. 20(A) is a schematic plan view corresponding to the expansion of Fig. 13. Fig. 20(B) or Fig. 20(C) is a schematic enlarged view of a region S3 of Fig. 20(A). Fig. 20(B) shows the clarity of the comparative example corresponding to Fig. 19(A). Fig. 20(C) shows a case corresponding to the embodiment of Fig. 19(B).

First, the case of the comparative example will be described. As described above, if the second support tape 100 is easily elongated, the region B of the second support tape 100 in Fig. 13 is difficult to be elongated. On the contrary, if the second support tape 100 is difficult to elongate, the region B of the second support tape 100 is easily elongated. Further, in the comparative example, the second support belt 100 is more likely to be elongated in the Y direction than in the X direction.

Therefore, as shown in FIG. 20(B), in the region B, the second support tape 100 is easily elongated in the X direction and is difficult to elongate in the Y direction. That is, the distance D1 between the semiconductor wafers 80 in the X direction is larger than the distance D2 between the semiconductor wafers 80 in the Y direction. Therefore, the DAF 200 included in the second support belt 100 is easily cut in the X direction, whereas it is difficult to be cut in the Y direction.

On the other hand, as shown in FIG. 20(C), when the difference between the nominal stress in the X direction and the easiness of elongation in the Y direction is small, the X direction and the Y direction are substantially uniformly expanded. That is, the X side The distance D3 to the semiconductor wafer 80 is substantially equal to the distance D4 in the Y direction. Therefore, the DAF 200 included in the second support belt 100 is equally cut in the X direction and the Y direction.

When the above is summarized, in order to prevent the DAF from being cut, the second support band preferably has a ratio of the nominal stress in the X direction to the nominal stress in the Y direction, that is, the anisotropy is small.

FIG. 21 is an experimental data obtained by plotting the relationship between the amount of expansion H and the distance D between the semiconductor wafers 80 for samples having different anisotropy of the second support strip 100. Furthermore, the elongation of the second support tape 100 used in this experiment was 90% or more. Further, in the present experiment, when the distance D is 40 μm or more, it means that the DAF is less defective in cutting, and the measurement data of about 50 points which are the same as the above-mentioned experiment are measured.

As shown in Fig. 21, when the ratio of the nominal stress is 1.7, even if the expansion amount H is set to 8 mm, DAF cut failure having a distance D of 40 μm or less occurs. On the other hand, when the ratio of the nominal stress is 1.4 and 1.0, if the expansion amount H is set to 8 mm, it is confirmed that the DAF is cut in all the measurement data. Therefore, the comparison between the nominal stress in the X direction of the second support tape 100 and the nominal stress in the Y direction is preferably 1.4 or less. Furthermore, it is a matter of course that when the nominal stress in the Y direction is stronger than the nominal stress in the X direction, the ratio becomes a reciprocal of 1.4, that is, about 0.7 or more.

Furthermore, as described above, making the nominal stress generated in the X direction and the Y direction close to 1 does not necessarily mean that the MD generated by the second support strip 100 and the nominal stress generated on the TD are close to 1. Even if the nominal stress generated on the MD and the TD is anisotropic, by attaching the second support strip 100 obliquely to the semiconductor wafer 80, the nominal stress generated in the X direction and the Y direction can be made close to 1.

Further, the relationship between the nominal strain of the second support tape 100 in the attached state and the tensile strength of the second support tape 100 and the DAF cut failure will be described.

As described with reference to Fig. 8, the second support tape 100 is attached while being stretched in the X direction. Therefore, the second support tape 100 is attached to the second surface 80b in a state of being elongated in the X direction. Moreover, the second support tape 100 is elongated and attached in the X direction, so if the second When the support belt 100 is expanded, the ease of elongation in the X direction and the Y direction is different. Assuming that the easiness of elongation in the X direction and the Y direction is different, as described in the anisotropy of the nominal stress, the DAF cut defect may be deteriorated.

In other words, not only the elongation of the second support tape 100 at the time of the fall and the anisotropy of the nominal stress but also the elongation of the second support tape in the X direction at the time of attachment can be further suppressed.

Fig. 22 is a graph showing the relationship between the nominal strain in the X direction of the second support tape 100 in the attached state and the DAF cut failure. Furthermore, the nominal strain in the X direction of the second support strip 100 is attached to the measured value at normal temperature.

As shown in FIG. 22, it is found that if the nominal strain in the X direction of the second support tape 100 exceeds 1.9%, DAF cut failure occurs. That is, it is known that if the nominal strain in the X direction of the second support strip 100 is at least less than 1.9%, it is advantageous to reduce the DAF cut failure.

In order to reduce the elongation in the X direction of the second support tape 100, it is sufficient that the second support tape 100 is not excessively stretched by the tensile force at the time of attachment. Specifically, if the tensile strength (the force required to elongate the unit length) of the second support tape 100 is large, the elongation in the X direction under the tensile force at the time of attachment can be reduced.

Fig. 23 is a table summarizing the nominal strain in the X direction, the difference in the distance D, the distance D, and the DAF cut defect in the tape of the sample having different tensile strengths of the second support tape. In Fig. 23, the tensile strength shows the respective data at normal temperature (24 ° C) and high temperature (70 ° C). Here, the normal temperature means, for example, 10 to 30 ° C, and for example, 40 to 90 ° C at a high temperature. The normal temperature is, for example, the temperature at the time of expansion, and the high temperature is, for example, the temperature at which the second support tape is attached.

Further, in Fig. 23, the tensile strength indicates the force necessary to elongate the second support tape 100 having a width of 20 mm by 2% in the nominal strain. The actual width of the second support strip 100 is, for example, a width of up to 350-390 mm with respect to a 300 mm semiconductor wafer. That is, with respect to the value shown in Fig. 23, when the force of about 17.5 times to 19.5 times is applied, the length of the second support tape 100 is extended by 2%.

Further, this experiment is a second support tape 100 in which the elongation at the time of lodging is 90% or more and the anisotropy of the nominal stress generated in the X direction and the Y direction is 1.2 or less. Even if the shortest distance from the distance D exceeds 40 μm, there is a disadvantage that the number of samples in Fig. 18 or Fig. 21 is about 50. In contrast, the number of samples in Fig. 23 is more than 350, which makes it more precise. Evaluation.

The experimental results of Fig. 23 will be described below.

Regarding the nominal strain of the belt, Comparative Example 1, Comparative Example 2, and Example were 2.1%, 0.8%, and 1.1%, respectively. It was found that the tensile strength at the normal temperature of Comparative Example 2 and the Example was larger than that of Comparative Example 1, and the nominal strain of the belt was decreased. In particular, in Comparative Example 2, the tensile strength at the normal temperature was the largest, and therefore the nominal strain of the belt was considered to be the smallest.

The minimum value of the distance D was 123 mm, 103 mm, and 156 mm in Comparative Example 1, Comparative Example 2, and Example, respectively. In the examples, with respect to Comparative Example 1 and Comparative Example 2, the minimum value of the distance D became large. The reason is considered to be that the tensile strength at a high temperature at the time of attachment of the second support tape 100 is large. Further, the minimum value of the distance D of Comparative Example 2 was smaller than that of Comparative Example 1. The reason was considered to be that the tensile strength at a high temperature was smaller than that of Comparative Example 1.

The standard deviation of the distance D was 12.4 mm, 17.1 mm, and 8.6 mm in Comparative Example 1, Comparative Example 2, and Example, respectively. In the examples, the standard deviation of the distance D was small with respect to Comparative Example 1 and Comparative Example 2. That is, the difference in the distance D of the embodiment is small. It is considered that the difference in the distance D is small as a result of the tensile strength at a high temperature as well as the minimum value of the distance D.

Finally, the DAF cut-off rate was 5.1%, 0.7%, and 0.0% in Comparative Example 1, Comparative Example 2, and Example, respectively. Although the nominal strain of the tape at the time of attachment was 1.1% worse than that of Comparative Example 2, the defective ratio was 0.0%, which was better than that of Comparative Example 2. It is considered that the reason why the minimum value of the distance D is larger and the standard deviation of the distance D is smaller than that of the comparative example 1 and the comparative example 2 is that the defect rate is small.

Summarize the experiment, if the nominal strain is 2% of the normal temperature, the tensile strength is greater than 2.8 [N/20 mm], it is easy to make the nominal strain of the attached second support tape 100 less than the above 1.9%. That is, the DAF cut failure can be reduced. Further, if the tensile strength at a high temperature is more than 1.6 [N/20 mm], the distance D can be further increased, and the standard deviation of the distance D can be further reduced. That is, DAF cut failure can be further reduced.

(Second embodiment)

The second embodiment will be described with reference to Figs. 24 to 28 . The same components as those in the first embodiment are denoted by the same reference numerals, and their description will be appropriately omitted.

As shown in FIG. 24, the first support tape 50 is attached to the first face 10a of the semiconductor wafer 10. In the present embodiment, the first support tape 50 is attached without forming the blade groove 30.

As shown in FIGS. 25 and 26, the semiconductor wafer 10 is turned upside down, and the laser 310 is used to cut from the second surface 10b side. Specifically, the modified region 320 is formed inside the semiconductor wafer 10 using the laser 310. A crack (cleavage plane) 330 is generated from the modified region 320 toward, for example, the lower side of the wafer. Furthermore, the cracks 330 can also be generated up and down.

As shown in FIGS. 27 and 28, the semiconductor wafer 10 is again inverted, and the second surface 10b is polished using the grinding stone 60. The back surface is polished in the same manner as in Fig. 5 of the first embodiment. Thereby, the semiconductor wafer 10 is then singulated into a plurality of semiconductor wafers 80 and defective wafers 85 by cracks 330. Further, since the cracks 330 are fine, there is a case where the cracks 330 cannot be visually recognized.

Hereinafter, a semiconductor device is manufactured by the same manufacturing method as that of the first embodiment.

The laser-based cutting is used in the second embodiment, which is different from the first embodiment. The second embodiment can prevent the yield from being lowered due to the generation of dust during cutting as compared with the cutting using the blade, and can also reduce the amount of pure water used for cleaning.

(variation)

In the above description, the semiconductor wafer 10 is polished by using a grinding grindstone after laser cutting. This grinding can also be carried out before laser cutting. For example, the semiconductor wafer 10 is previously thinned by grinding. Thereafter, the semiconductor wafer 10 is shaped using a laser-based cut. The cracks 330 reach the first surface 10a and the second surface 10b of the semiconductor wafer 10.

(Third embodiment)

In the first embodiment and the second embodiment, the direction in which the second support tape 100 is attached is substantially parallel or substantially orthogonal to the cutting direction of the semiconductor wafer 10, but the invention is not limited thereto.

For example, it is also possible to incline 45 degrees from the cutting direction of the semiconductor wafer 10. In this case, for example, it can be expanded more uniformly.

(Fourth embodiment)

The fourth embodiment will be described with reference to Fig. 29 . 29(a) and (b) show the method of the tensile test of the belt 510. Fig. 29 (a) shows the state before stretching, and Fig. 29 (b) shows the state after stretching.

The stent 500 stretches both ends of the belt 510, whereby the tensile strength, nominal stress, nominal strain, elongation, and the like of the belt 510 can be determined. The strap 510 is, for example, a second support strap 100.

As shown in Figs. 29(a) and (b), after stretching, the belt 510 is a belt 510' whose width is reduced from W1 to W2.

On the other hand, FIG. 29(c) shows a state in which the tape 510 is stretched in a state of being attached to the semiconductor wafer 10. As shown in Fig. 29 (c), the belt 510 is stretched in all directions, so that the thickness thereof does not become thin as shown in Fig. 29 (b).

That is, in the method of the tensile test of the tape 510 shown in FIGS. 29(a) and 29(b), there is a case where stress, strain, and the like in a state of being attached to the wafer 10 cannot be appropriately calculated. Therefore, the true stress (True Stress) and the true strain (True Strain) expressed by the following relationship are used.

σ _t =σ _n (ε _n +1)

ε _t =ln(ε _n +1)

Here, σ _t is the true stress, σ _n is the nominal stress, ε _t is the true strain, and ε _n is the nominal strain. The true stress and the true strain can be evaluated in a state where the effect of the tape 510 is reduced in the tensile test and the environment in which the tape 10 is actually used is lowered.

Fig. 30 is a view showing a comparison between the case where the same sample is evaluated by the nominal stress and the nominal strain (Fig. 30 (a)) and the case where the evaluation is performed using the true stress and the true strain (Fig. 30 (b)).

As shown in Fig. 30 (a), if the nominal stress and the nominal strain are used, the elongation at the time of the fall of the sample is about 20%. On the other hand, as shown in Fig. 30(b), if true stress and true strain are used, the sample does not fall, but breaks at about 250% of the true strain.

That is, in the case where the sample of Fig. 30 is evaluated by the nominal stress or the nominal strain, the elongation at the time of the fall is 90% or less, and there is a concern that DAF cut failure occurs. However, if the evaluation is performed using real stress and true strain, it will not fall. Moreover, it was confirmed in experiments by the inventors and the like that it is more appropriate to evaluate with actual stress and true strain in the actual sample.

Fig. 31 is a table summarizing the results of evaluation experiments for the DAF cut failure test in the samples A to F of the second support tape 100. The table of Fig. 31 shows the evaluation results of each sample, the elongation at the time of using the nominal strain, the nominal stress, the nominal strain and the true strain at the time of the fracture or the fall when the true stress is used. Furthermore, each value is represented separately for MD and TD.

With respect to the experiment of FIG. 31, the evaluation of the DAF cut failure test is the evaluation test result for the semiconductor wafer 10 in the same manner as in FIG. 23 and the like. The measurement of the elongation at break, the nominal strain, the true strain, and the like was measured using an Autograph (type AGS-D) manufactured by Shimadzu Corporation. The tensile speed at the time of the test was 500 mm/min.

The evaluation of the DAF cut failure was performed, and the samples A to C and E were good, and the samples D and F were more likely to be defective.

For example, as can be seen by observing the sample A of Fig. 31, the elongation at the time of the use of the nominal stress is 28%, 20%, and less than 90%. On the other hand, when the true stress is used, the elongation at break or at the time of the fall is large, which is 105% and 124%. And, actually, sample A The evaluation of poor DAF cuts was good.

On the other hand, when the sample D used the nominal stress, the elongation at the time of the fall was 30% and 30%, which was substantially the same as the sample A. On the other hand, when the true stress is used, the elongation at break or at the time of the fall is 199%, 25%, which is significantly worse than the sample A in terms of TD. Moreover, the evaluation of the DAF cut defect in the sample D was actually not good.

That is, there is a case where the elongation at the time of fracture or the fall at the time of using the true stress is further related to the poor DAF cut.

According to the results of Fig. 31, in the samples A to C and E in which the DAF was poorly cut, the elongation at the time of the fracture using the true stress or the minimum at the time of the fall was 72% of the TD of the sample C. In other words, when it is 72% or more, a good result can be expected with respect to DAF cut failure.

Furthermore, in the bad samples D and F, it is considered that the smaller value of MD and TD is related to the poor DAF cut, so it is necessary to evaluate the smaller of the values of MD and TD. In the samples D and F, the maximum elongation at break or at the time of the fall when using the true stress was 39% of the sample F.

The embodiments of the present invention have been described, but the embodiments are presented as examples and are not intended to limit the scope of the invention. The present invention may be embodied in various other forms, and various omissions, substitutions and changes may be made without departing from the scope of the invention. The present invention and its modifications are intended to be included within the scope and spirit of the invention, and are included in the scope of the invention described in the claims.

Claims (7)

A method of fabricating a semiconductor device, comprising: a step of attaching a first support strip to a first side of a semiconductor wafer; a step of singulating the semiconductor wafer into a plurality of semiconductor wafers; and a second support strip a step of attaching the first direction to the second surface of the plurality of semiconductor wafers; a step of stripping the first support strip from the plurality of semiconductor wafers; and expanding the semiconductor wafer by extending the second support strip a step of a distance therebetween; and a ratio of a nominal stress generated by the elongation of the second support strip relative to the first direction to a nominal stress generated by elongation with respect to a second direction crossing the first direction is 0.7~1.4. The method of manufacturing a semiconductor device according to claim 1, wherein the second support tape has an elongation at which the elongation is 90% or more. The method of manufacturing a semiconductor device according to claim 1, wherein the second support tape has an elongation at break or a fall of 72% or more when the true stress is used. The method of manufacturing the semiconductor device of claim 1, wherein the force required for the second support strip to elongate the second support strip having a width of 20 mm by 2% is greater than 2.8 [N] at 24 degrees, at 70 degrees Greater than 1.6 [N]. The method of manufacturing a semiconductor device according to claim 1, wherein the second support strip has a nominal strain of 1.9% or less in the first direction at a normal temperature after the attachment. The method of manufacturing a semiconductor device according to any one of claims 1 to 5, further comprising the step of forming a blade groove on the semiconductor wafer using the blade before the step of attaching the first support tape, the singulation The steps are performed by: for the above semiconductor wafer The second surface opposite to the first surface is ground to cause the insert pocket to reach the second surface. The method of manufacturing a semiconductor device according to any one of claims 1 to 5, wherein the singulation step is performed by irradiating the semiconductor wafer with a laser to form a cleavage surface.