WO2014050663A1

WO2014050663A1 - Adhesive sheet for semiconductor device production, semiconductor device, and method for producing semiconductor device

Info

Publication number: WO2014050663A1
Application number: PCT/JP2013/075174
Authority: WO
Inventors: 宇圓田　大介; 石井　淳
Original assignee: 日東電工株式会社
Priority date: 2012-09-28
Filing date: 2013-09-18
Publication date: 2014-04-03
Also published as: TW201417161A

Abstract

The objective of the present invention is to provide an adhesive sheet that is for semiconductor device production, can be firmly affixed to the pedestal of a semiconductor wafer, and is such that the pedestal is easily separated from the semiconductor wafer. The present invention pertains to the adhesive sheet for semiconductor device production and used for affixing a semiconductor wafer to a pedestal, wherein the adhesive sheet has a first adhesive layer and a second layer having a lower adhesive strength than the first adhesive layer, and at least the peripheral section of the adhesive sheet for semiconductor device production is formed from a first adhesive layer.

Description

Adhesive sheet for manufacturing semiconductor device, semiconductor device, and method for manufacturing semiconductor device

The first aspect of the present invention relates to an adhesive sheet for manufacturing a semiconductor device, a semiconductor device, and a method for manufacturing the semiconductor device.

Conventionally, in a semiconductor device manufacturing process, after a semiconductor wafer is temporarily fixed on a pedestal, a predetermined process such as back grinding is performed on the semiconductor wafer, and then the pedestal is separated from the semiconductor wafer. There is. In such a process, it is important that the pedestal can be easily separated from the semiconductor wafer.

As a method for temporarily fixing a semiconductor wafer on a pedestal, it is known to use a liquid adhesive. The liquid adhesive is applied to the semiconductor wafer or the pedestal by spin coating.

In Patent Document 1, a device wafer as a first substrate and a carrier substrate as a second substrate are pressure-bonded through a filling layer that does not form a strong adhesive bond, and a bonding material is filled into the periphery of the filling layer. A method of forming an edge bond by curing and bonding the first substrate and the second substrate is disclosed.

Patent Document 2 discloses a bonding composition layer containing a compound selected from the group consisting of oligomers and polymers, selected from the group consisting of polymers and oligomers of imides, amidoimides and amidoimide-siloxanes. A method of joining the first substrate and the second substrate via the above is disclosed.

Special table 2011-510518 gazette Special table 2010-53385 gazette

The filling layer described in Patent Document 1 and the bonding composition layer described in Patent Document 2 are applied by spin coating or the like. However, if a layer with a thickness of 10 μm or more necessary for adhesion is formed by coating, the coated surface is generally rough, the unevenness followability is poor, the desired adhesive force cannot be obtained, and the semiconductor wafer is sufficiently fixed to the pedestal. There are cases where it is not possible.

In addition, when applying by spin coating, there is a problem that most of the material is wasted. In addition, since the material has a high viscosity for bonding, labor is required to remove the dirt on the spin coater.

The first aspect of the present invention has been made in view of the above problems, and it is an object of the present invention to provide an adhesive sheet for manufacturing a semiconductor device that can firmly fix a semiconductor wafer to a pedestal and easily separate the pedestal from the semiconductor wafer. Another object of the present invention is to provide a semiconductor device using the adhesive sheet for manufacturing a semiconductor device and a method for manufacturing the semiconductor device.

The inventor of the present application has found that the above problem can be solved by adopting the following configuration, and has completed the first present invention.

That is, the first aspect of the present invention is an adhesive sheet for manufacturing a semiconductor device used for fixing a semiconductor wafer to a pedestal, and includes a first adhesive layer and a second adhesive force lower than that of the first adhesive layer. And at least a peripheral portion of the adhesive sheet for manufacturing a semiconductor device is formed of the first adhesive layer.

Since the adhesive sheet is in the form of a sheet, the surface can be formed more uniformly than when the adhesive layer is formed by spin coating. Furthermore, the material is not wasted like spin coating. Moreover, since it is a sheet form, it can be used simply.

Moreover, the peripheral part of the said adhesive sheet is formed of the said 1st adhesive bond layer. Since the first adhesive layer having a higher adhesive force than the second layer is present in the peripheral portion, the semiconductor wafer can be firmly fixed to the pedestal in this portion.
Moreover, since it has not only the 1st adhesive layer but the 2nd layer whose adhesive force is lower than the 1st adhesive layer, if even the adhesive force of the 1st adhesive layer is lowered, it will be removed from the semiconductor wafer by external force. The pedestal can be easily separated.
As a method for reducing the adhesive strength of the first adhesive layer, a method of reducing the adhesive strength by dissolving the first adhesive layer with a solvent, a physical cutting with a cutter, laser or the like in the first adhesive layer. Examples thereof include a method for reducing the adhesive strength by heating, a method for forming the first adhesive layer with a material whose adhesive strength decreases by heating, and a method for decreasing the adhesive strength by heating. Since the first adhesive layer is formed in the peripheral portion of the adhesive sheet, the first adhesive layer is dissolved by a solvent, or physically cut by a cutter or a laser, It is easy to reduce the adhesive force of one adhesive layer, and to easily separate the pedestal from the semiconductor wafer.

In the first aspect of the present invention, the adhesive strength of the first adhesive layer and the adhesive strength of the second layer are the 90 ° peel peeling from the silicon wafer under the conditions of a temperature of 23 ± 2 ° C. and a peeling speed of 300 mm / min. I say power. In addition, when a 1st adhesive bond layer is what adhere | attaches by performing imidation, thermosetting, etc., the 90 degree peel peel force in the state (for example, after imidation or after thermosetting) fixed to the silicon wafer. Say. When the second layer is bonded by imidization, thermosetting, or the like, it means 90 ° peel peeling force in a state of being fixed to a silicon wafer (for example, after imidization or after thermosetting). Specifically, it can be measured by the method described in the examples.

In the adhesive sheet, it is preferable that a central portion inside the peripheral portion is formed by stacking the first adhesive layer and the second layer. According to the said structure, a semiconductor wafer or a base can be firmly fixed in the surface which only the 1st adhesive bond layer has exposed. In addition, since the central portion is formed by stacking the first adhesive layer and the second layer, the central portion is relatively bonded to the peripheral portion formed only by the first adhesive layer. Power is low. Therefore, the base can be easily separated from the semiconductor wafer by an external force if at least the adhesive strength of the peripheral portion is reduced. Further, when the second layer is in contact with the pedestal, the adhesive sheet is easily peeled off from the pedestal, the adhesive residue is small, and the pedestal is easy to reuse.

In the adhesive sheet, it is also preferable that a central portion inside the peripheral portion is formed by the second layer. According to the said structure, since the center part is formed with the 2nd layer, if the adhesive force of a 1st adhesive bond layer is reduced, a base can be easily isolate | separated from a semiconductor wafer by external force. Further, since the second layer is in contact with the pedestal, the adhesive sheet is easily peeled off from the pedestal, the adhesive residue is small, and the pedestal is easy to reuse.

It is preferable that a third layer having a lower adhesive force than the first adhesive layer is formed over the peripheral portion and the central portion. When the surface on which the third layer having a lower adhesive strength than the first adhesive layer is exposed is attached to the semiconductor wafer, the adhesive sheet can be easily peeled from the semiconductor wafer. Further, the adhesive residue on the semiconductor wafer can be eliminated, and the semiconductor wafer cleaning step can be omitted.

The first aspect of the present invention also relates to a semiconductor device obtained using the adhesive sheet for manufacturing a semiconductor device.

The first aspect of the present invention also relates to a method for manufacturing a semiconductor device, comprising: a step of fixing a semiconductor wafer to a pedestal using the adhesive sheet for manufacturing a semiconductor device; and a step of separating the pedestal from the semiconductor wafer.

The 2-1 of the present invention is an adhesive sheet for manufacturing a semiconductor device used for fixing a semiconductor wafer to a pedestal, and includes a first adhesive layer and a second adhesive layer having an adhesive force lower than that of the first adhesive layer. The present invention relates to an adhesive sheet for manufacturing a semiconductor device.

Moreover, the 1st adhesive bond layer and the 2nd layer whose adhesive force is lower than the said 1st adhesive bond layer are laminated | stacked. Since it has a 1st adhesive bond layer, a semiconductor wafer can be favorably fixed to a base. Since the second layer having a lower adhesive force than the first adhesive layer is provided, the pedestal can be easily separated from the semiconductor wafer by an external force.

In the 2-1st aspect of the present invention, the adhesive strength of the first adhesive layer and the adhesive strength of the second layer are 90 ° with respect to a silicon wafer under conditions of a temperature of 23 ± 2 ° C. and a peeling speed of 300 mm / min. Refers to peel strength. In addition, in the adhesive sheet which fixes a semiconductor wafer to a base by performing imidation, thermosetting, etc., the 90 degree peel peeling force in the state (for example, after imidation or after thermosetting) fixed to a silicon wafer is said. Specifically, it can be measured by the method described in the examples.

The 2-1st aspect of the present invention also relates to a method for manufacturing a semiconductor device, including a step of fixing a semiconductor wafer to a pedestal using the adhesive sheet for manufacturing a semiconductor device, and a step of separating the pedestal from the semiconductor wafer.

The step of fixing the semiconductor wafer to the pedestal using the adhesive sheet for manufacturing a semiconductor device includes attaching the semiconductor wafer to the first adhesive layer and attaching the pedestal to the second layer. Preferably, the step of fixing the semiconductor wafer to the pedestal.

The first adhesive layer has a higher adhesive force than the second layer, and is excellent in unevenness followability such as the surface of a semiconductor wafer. According to the said structure, since a 1st adhesive bond layer can track the unevenness | corrugation on the surface of a semiconductor wafer, a semiconductor wafer can be favorably fixed to a base. On the other hand, since the 2nd layer whose adhesive force is lower than a 1st adhesive bond layer contacts a base, it is easy to peel an adhesive sheet from a base. In addition, there is little adhesive residue on the pedestal and it is easy to reuse the pedestal.

The 2-2 of the present invention is obtained by the step (A) of attaching a semiconductor wafer to the adhesive sheet (a), the step (B) of attaching a base to the adhesive sheet (b), and the step (A). Bonding the adhesive sheet (a) of the semiconductor wafer with the adhesive sheet (a) and the adhesive sheet (b) of the base with the adhesive sheet (b) obtained by the step (B) (C) In addition, the present invention relates to a method for manufacturing a semiconductor device in which one adhesive force of the adhesive sheets (a) and (b) is lower than the other.

Since the sheet-like adhesive sheets (a) and (b) are used, materials are not wasted unlike spin coating.

Moreover, one adhesive force of the said adhesive sheet (a) and (b) is lower than the other. For this reason, it is easy to separate the pedestal from the semiconductor wafer. In addition, since the adhesive sheet having a relatively high adhesive force is used, the semiconductor wafer can be satisfactorily fixed to the pedestal.

In the 2-2 of the present invention, the adhesive strength of the adhesive sheet (a) and the adhesive strength of the adhesive sheet (b) are 90 ° C. on a silicon wafer under the conditions of a temperature of 23 ± 2 ° C. and a peeling speed of 300 mm / min. ° Peel peeling force. In the case where the adhesive sheets (a) and (b) are bonded by imidization or thermosetting, 90 ° in a state fixed to the silicon wafer (for example, after imidization or thermosetting). Refers to peel strength. Specifically, it can be measured by the method described in the examples.

It is preferable that the adhesive strength of the adhesive sheet (b) is lower than that of the adhesive sheet (a).

According to the said structure, an adhesive sheet (a) has higher adhesive force than an adhesive sheet (b), and is excellent in uneven | corrugated followable | trackability, such as a semiconductor wafer surface. Since the adhesive sheet (a) can follow the irregularities on the surface of the semiconductor wafer, the semiconductor wafer can be satisfactorily fixed to the pedestal. On the other hand, since the adhesive sheet (b) having an adhesive force lower than that of the adhesive sheet (a) is in contact with the pedestal, the adhesive sheet (b) is easily peeled from the pedestal. In addition, there is little adhesive residue on the pedestal and it is easy to reuse the pedestal.

The third aspect of the present invention includes a step (A) of attaching a semiconductor wafer to one surface of the temporary fixing sheet, a step (B) of attaching a pedestal having a beveled portion to the other surface of the temporary fixing sheet, and (C) a step of forming an adhesive layer having a higher adhesive force than the temporary fixing sheet between the temporary fixing sheet and the bevel portion of the pedestal, and fixing the temporary fixing sheet to the pedestal. The present invention relates to a method for manufacturing a semiconductor device including:

The temporary fixing sheet used in the third aspect of the present invention is in the form of a sheet, and the surface can be formed more uniformly than when the adhesive layer is formed by spin coating. For this reason, the temporary fixing sheet can be satisfactorily bonded to the semiconductor wafer. Moreover, since the adhesive layer having higher adhesive strength than the temporary fixing sheet is used, the temporary fixing sheet can be firmly fixed to the pedestal. As a result, the semiconductor wafer can be satisfactorily fixed to the pedestal.

In the third aspect of the present invention, an adhesive layer having a higher adhesive force than the temporary fixing sheet is formed between the temporary fixing sheet and the bevel portion of the pedestal, and the temporary fixing sheet is fixed to the pedestal. That is, the adhesive layer plays a role of fixing the temporary fixing sheet to the base.
In the third invention, since the adhesive layer is formed between the temporary fixing sheet and the bevel portion of the pedestal, the temporary fixing sheet may be cut or the adhesive force of the adhesive layer may be reduced. It is easy and separation can be performed easily.

In the third aspect of the present invention, the adhesive strength of the temporary fixing sheet and the adhesive strength of the adhesive layer are the 90 ° peel peel force on a silicon wafer under the conditions of a temperature of 23 ± 2 ° C. and a peel rate of 300 mm / min. Say. In addition, when the sheet | seat for temporary fixing performs imidation, thermosetting, etc. and makes it adhere | attach, the 90 degree peel peeling force in the state (for example, after imidation or after thermosetting) fixed to the silicon wafer is said. In the case where the adhesive layer is bonded by imidization or thermosetting, it means 90 ° peel peel force in a state where it is fixed to a silicon wafer (for example, after imidization or after thermosetting). Specifically, it can be measured by the method described in the examples.

After the step (C), it is preferable to include a step of separating the pedestal from the temporary fixing sheet.

The 4-1 of the present invention includes a first adhesive layer and a second layer having an adhesive strength lower than that of the first adhesive layer, and a peripheral portion of the adhesive sheet is formed by the first adhesive layer. A step of preparing an adhesive sheet in which a central portion inside the peripheral portion is formed by stacking the first adhesive layer and the second layer; and a semiconductor wafer is mounted using the adhesive sheet And a step of cutting the first adhesive layer until reaching the second layer to separate the pedestal from the semiconductor wafer.

In the 4-1 of the present invention, first, an adhesive sheet is prepared. Since the adhesive sheet is in the form of a sheet, the surface can be formed more uniformly than when the adhesive layer is formed by spin coating. Furthermore, the material is not wasted like spin coating. Moreover, since it is a sheet form, it can be used simply.

The peripheral part of the adhesive sheet is formed by the first adhesive layer. Since the first adhesive layer having a higher adhesive force than the second layer is present in the peripheral portion, the semiconductor wafer can be firmly fixed to the pedestal in this portion.
Moreover, the center part inside a peripheral part is formed by lamination | stacking with a 1st adhesive bond layer and a 2nd layer. On the surface where only the first adhesive layer is exposed, the semiconductor wafer or the pedestal can be firmly fixed. Further, when the second layer is in contact with the pedestal, the adhesive sheet is easily peeled off from the pedestal, the adhesive residue is small, and the pedestal is easy to reuse.

In the separation step, the first adhesive layer is cut. Thereby, the continuity of a 1st adhesive bond layer can be destroyed and a base can be easily isolate | separated from a semiconductor wafer. Moreover, since the 1st adhesive bond layer is formed in the peripheral part of the adhesive sheet, it is easy to cut | disconnect a 1st adhesive bond layer.

In the 4-1 of the present invention, the adhesive strength of the first adhesive layer and the adhesive strength of the second layer are 90 ° with respect to a silicon wafer under conditions of a temperature of 23 ± 2 ° C. and a peeling speed of 300 mm / min. Refers to peel strength. In addition, when a 1st adhesive bond layer is what adhere | attaches by performing imidation, thermosetting, etc., the 90 degree peel peel force in the state (for example, after imidation or after thermosetting) fixed to the silicon wafer. Say. When the second layer is bonded by imidization, thermosetting, or the like, it means 90 ° peel peeling force in a state of being fixed to a silicon wafer (for example, after imidization or after thermosetting). Specifically, it can be measured by the method described in the examples.

The present invention of No. 4-2 includes a first adhesive layer and a second layer having an adhesive strength lower than that of the first adhesive layer, and a peripheral portion of the adhesive sheet is formed by the first adhesive layer. A step of preparing an adhesive sheet in which a central portion inside the peripheral portion is formed by the second layer, a step of fixing a semiconductor wafer to a pedestal using the adhesive sheet, and the second And a step of cutting the first adhesive layer until reaching the layer, and separating the pedestal from the semiconductor wafer.

In the 4-2 of the present invention, first, an adhesive sheet is prepared. Since the adhesive sheet is in the form of a sheet, the surface can be formed more uniformly than when the adhesive layer is formed by spin coating. Furthermore, the material is not wasted like spin coating. Moreover, since it is a sheet form, it can be used simply.

The peripheral part of the adhesive sheet is formed by the first adhesive layer. Since the first adhesive layer having a higher adhesive force than the second layer is present in the peripheral portion, the semiconductor wafer can be firmly fixed to the pedestal in this portion.
In addition, a central portion inside the peripheral portion is formed by the second layer. Since the second layer is in contact with the pedestal, the adhesive sheet is easily peeled off, the adhesive residue is small, and the pedestal is easy to reuse.

In the separation step, the first adhesive layer is cut. Thereby, the continuity of a 1st adhesive bond layer can be destroyed and a base can be easily isolate | separated from a semiconductor wafer. Moreover, since the 1st adhesive bond layer is formed in the peripheral part of the adhesive sheet, it is easy to make a cut | incision in a 1st adhesive bond layer.

In the 4-2th invention, the definition of the adhesive force of the first adhesive layer and the adhesive force of the second layer is the same as in the case of the 4-1 invention.

The present invention of No. 4-3 provides a step of preparing an adhesive sheet in which a first adhesive layer and a second layer having an adhesive strength lower than that of the first adhesive layer are laminated, and using the adhesive sheet Fixing the semiconductor wafer to the pedestal, and cutting the boundary between the first adhesive layer and the second layer to separate the first adhesive layer and the second layer. The present invention relates to a method for manufacturing a semiconductor device.

In the fourth to third present invention, first, an adhesive sheet is prepared. Since the adhesive sheet is in the form of a sheet, the surface can be formed more uniformly than when the adhesive layer is formed by spin coating. Furthermore, the material is not wasted like spin coating. Moreover, since it is a sheet form, it can be used simply.

The said adhesive sheet is a laminated body of a 1st adhesive bond layer and a 2nd layer whose adhesive force is lower than a 1st adhesive bond layer. In the fixing step, this is used to fix the semiconductor wafer to the pedestal. Since the adhesive sheet having the first adhesive layer is used, the semiconductor wafer can be satisfactorily fixed to the pedestal.

In the separation step, a cut is made at the boundary between the first adhesive layer and the second layer having a lower adhesive force than the first adhesive layer. Since the adhesive force of the second layer is lower than that of the first adhesive layer, the first adhesive layer and the second layer can be easily separated starting from the cut portion.

In the 4th invention, the definitions of the adhesive strength of the first adhesive layer and the adhesive strength of the second layer are the same as in the case of the 4th invention.

The step of fixing the semiconductor wafer to the pedestal using the adhesive sheet includes attaching the semiconductor wafer to the first adhesive layer and attaching the pedestal to the second layer. It is preferable that it is the process of fixing to the said base.

The 4-4th aspect of the present invention is obtained by the step (A) of attaching a semiconductor wafer to the adhesive sheet (a), the step (B) of attaching a pedestal to the adhesive sheet (b), and the step (A). The adhesive sheet (a) of the semiconductor wafer with the adhesive sheet (a) and the adhesive sheet (b) of the base with the adhesive sheet (b) obtained by the step (B) are bonded together, and the base and the adhesive Step (C) for obtaining a laminate in which the sheet (b), the adhesive sheet (a), and the semiconductor wafer are sequentially laminated, and the boundary between the adhesive sheet (a) and the adhesive sheet (b) in the laminate A step (D) for separating the adhesive sheet (a) and the adhesive sheet (b), wherein one adhesive force of the adhesive sheets (a) and (b) is lower than the other. The present invention relates to a method for manufacturing a semiconductor device.

Since the sheet-like adhesive sheets (a) and (b) are used, the material is not wasted like spin coating.

In the step of obtaining the laminate, not only an adhesive sheet having a low adhesive strength but also an adhesive sheet having a relatively high adhesive strength is used together, so that the semiconductor wafer can be satisfactorily fixed to the pedestal.

In the separation step, a cut is made at the boundary between the adhesive sheet (a) and the adhesive sheet (b) in the laminate. Since the adhesive strength of one of the adhesive sheets (a) and (b) is lower than the other, the adhesive sheets (a) and (b) can be easily separated from the notched portion.

In the 4-4th aspect of the present invention, the adhesive strength of the adhesive sheet (a) and the adhesive strength of the adhesive sheet (b) are 90 ° with respect to a silicon wafer under conditions of a temperature of 23 ± 2 ° C. and a peeling speed of 300 mm / min. ° Peel peeling force. When the adhesive sheet (a) is bonded by imidization or thermosetting, the 90 ° peel peel force in a state fixed to the silicon wafer (for example, after imidization or after thermosetting) Say. In the case where the adhesive sheet (b) is bonded by imidization or thermosetting, it means 90 ° peel peeling force in a state of being fixed to a silicon wafer (for example, after imidization or after thermosetting). Specifically, it can be measured by the method described in the examples.

According to the said structure, an adhesive sheet (a) has higher adhesive force than an adhesive sheet (b), and is excellent in uneven | corrugated followable | trackability, such as a semiconductor wafer surface. Since the adhesive sheet (a) can follow the irregularities on the surface of the semiconductor wafer, the semiconductor wafer can be satisfactorily fixed to the pedestal. On the other hand, since the adhesive sheet (b) having an adhesive force lower than that of the adhesive sheet (a) is in contact with the pedestal, the adhesive sheet (b) is easily peeled from the pedestal. In addition, there is little adhesive residue on the pedestal and the pedestal is easy to reuse.

The 4-5th aspect of the present invention includes a step (I) of attaching a semiconductor wafer to one surface of the temporary fixing sheet;
The step (II) of attaching a pedestal having a beveled portion to the other surface of the temporary fixing sheet, and the adhesive strength between the temporary fixing sheet and the beveled portion of the pedestal is higher than that of the temporary fixing sheet. Forming a high temporary adhesive layer and fixing the temporary fixing sheet to the pedestal (III); and after the steps (I) to (III), cutting the temporary fixing sheet And a step (IV) of separating the pedestal from the temporary fixing sheet.

The temporary fixing sheet has a sheet shape, and the surface can be formed more uniformly than when the adhesive layer is formed by spin coating. For this reason, the temporary fixing sheet can be satisfactorily bonded to the semiconductor wafer. In addition, since the temporary fixing adhesive layer having higher adhesive strength than the temporary fixing sheet is used, the temporary fixing sheet can be firmly fixed to the pedestal. Accordingly, the semiconductor wafer can be satisfactorily fixed to the pedestal.

In step (IV), a cut is made in the temporary fixing sheet. Thereby, the continuity of the temporary fixing sheet can be destroyed, and the pedestal can be easily separated from the temporary fixing sheet. Further, since the temporary fixing adhesive layer is formed between the temporary fixing sheet and the bevel portion of the pedestal, it is easy to cut the temporary fixing sheet.

In the 4-5th aspect of the present invention, the adhesive strength of the temporary fixing sheet and the adhesive strength of the temporary adhesive layer are 90 ° to silicon wafer under the conditions of a temperature of 23 ± 2 ° C. and a peeling speed of 300 mm / min. ° Peel peeling force. In addition, when the sheet | seat for temporary fixing performs imidation, thermosetting, etc. and makes it adhere | attach, the 90 degree peel peeling force in the state (for example, after imidation or after thermosetting) fixed to the silicon wafer is said. When the temporary fixing adhesive layer is bonded by imidization or thermosetting, it means 90 ° peel peel force in a state of being fixed to a silicon wafer (for example, after imidization or after thermosetting). Specifically, it can be measured by the method described in the examples.

5th this invention is the adhesive sheet for semiconductor device manufacture used in order to fix a semiconductor wafer to a base, Comprising: The structure and / or nonwoven fabric-like structure which have a 1st adhesive bond layer and many through-holes And a second layer having a body as a skeleton, wherein the adhesive strength of the second layer is lower than the adhesive strength of the first adhesive layer.

Since the adhesive sheet has a sheet shape, the material is not wasted unlike spin coating. In addition, it is not necessary to remove the dirt on the spin coater, and the apparatus maintenance is easy. Since the adhesive sheet is in the form of a sheet, the surface of the first adhesive layer can be formed more uniformly than when the adhesive layer is formed by spin coating, and the adhesive force of the first adhesive layer can be improved.

Since the said adhesive sheet has a 1st adhesive bond layer, a semiconductor wafer can be favorably fixed to a base. On the other hand, since the second layer having a lower adhesive force than the first adhesive layer is provided, the pedestal can be easily separated from the semiconductor wafer by an external force.

The second layer is a layer having a structure having a large number of through holes and / or a non-woven structure as a skeleton, and can be formed of a mesh such as a wire mesh, a non-woven fabric, or the like. For this reason, what is necessary is just to prepare the adhesive composition of a 1st adhesive bond layer as an adhesive material in manufacture of an adhesive sheet, and it is not necessary to prepare two types of adhesives, a filling layer and an edge bond like patent document 1. .

In the fifth aspect of the present invention, the adhesive strength of the first adhesive layer and the adhesive strength of the second layer are: 90 ° peel peeling with respect to a silicon wafer under conditions of a temperature of 23 ± 2 ° C. and a peeling speed of 300 mm / min. I say power. In addition, when a 1st adhesive bond layer is what adhere | attaches by performing imidation, thermosetting, etc., the 90 degree peel peel force in the state (for example, after imidation or after thermosetting) fixed to the silicon wafer. Say. The same applies to the second layer. Specifically, it can be measured by the method described in the examples.

It is preferable that the through holes and the pores of the nonwoven fabric-like structure are filled with an adhesive composition. In this case, the area where the adhesive composition comes into contact with the semiconductor wafer or the pedestal can be controlled by the aperture ratio of the structure having through holes, the density of the non-woven structure, etc. Can be formed.

It is preferable that at least a peripheral portion of the adhesive sheet for manufacturing a semiconductor device is formed by the first adhesive layer.
Since the peripheral part of the said adhesive sheet is formed of the 1st adhesive bond layer, it can fix favorably in this part.

It is preferable that a central portion inside the peripheral portion is formed by stacking the first adhesive layer and the second layer.
According to the said structure, a semiconductor wafer or a base can be firmly fixed by the surface which consists only of a 1st adhesive bond layer. The semiconductor wafer or the pedestal can be satisfactorily fixed on the surface having the first adhesive layer and the second layer.
Further, since the first adhesive layer is formed in the peripheral portion of the adhesive sheet, it is easy to cut the first adhesive layer or to reduce the adhesive force of the first adhesive layer, and to be easily separated. Can be done.

In the adhesive sheet, it is also preferable that a central portion inside the peripheral portion is formed by the second layer. According to the said structure, a semiconductor wafer or a base can be favorably fixed by the surface which has a 1st adhesive bond layer and a 2nd layer.
Further, since the first adhesive layer is formed in the peripheral portion of the adhesive sheet, it is easy to cut the first adhesive layer or to reduce the adhesive force of the first adhesive layer, and to be easily separated. Can be done.

The adhesive sheet is preferably formed by stacking the first adhesive layer and the second layer.

The fifth aspect of the present invention also relates to a method for manufacturing a semiconductor device, comprising: a step of fixing a semiconductor wafer to a pedestal using the adhesive sheet for manufacturing a semiconductor device; and a step of separating the pedestal from the semiconductor wafer.

According to the first aspect of the present invention, the semiconductor wafer can be firmly fixed to the pedestal, and the pedestal can be easily separated from the semiconductor wafer.

It is a cross-sectional schematic diagram of the adhesive sheet of Embodiment 1 of 1st this invention. It is a top view of the adhesive sheet of Embodiment 1 of the 1st present invention. It is a cross-sectional schematic diagram of the adhesive sheet of Embodiment 2 of 1st this invention. It is a top view of the adhesive sheet of Embodiment 2 of the 1st present invention. It is a cross-sectional schematic diagram of an adhesive sheet provided with the 3rd layer of 1st this invention. It is a cross-sectional schematic diagram of an adhesive sheet provided with the 3rd layer of 1st this invention. It is a schematic diagram which shows a mode that the semiconductor wafer was fixed to the base using the adhesive sheet of Embodiment 1 of 1st this invention. It is a cross-sectional schematic diagram of the adhesive sheet of Embodiment 2-1 of the 2-1 of this invention. It is a cross-sectional schematic diagram of the adhesive sheet of Embodiment 2-1 of the 2-1 of this invention. It is a schematic diagram which shows a mode that the semiconductor wafer was affixed on the adhesive sheet of Embodiment 2-1 of the 2nd this invention. It is a schematic diagram which shows a mode that the semiconductor wafer was fixed to the base using the adhesive sheet of Embodiment 2-1 of the 2nd this invention. It is a cross-sectional schematic diagram of the adhesive sheet (a) of the 2-2 of the present invention. It is a schematic diagram showing a state where a semiconductor wafer is attached to the adhesive sheet (a) of the 2-2 of the present invention. It is a cross-sectional schematic diagram of the adhesive sheet (b) of the 2-2 of the present invention. It is a schematic diagram showing a state where a pedestal is attached to the adhesive sheet (b) of the 2-2 of the present invention. It is a schematic diagram showing a state in which a semiconductor wafer is fixed to a pedestal using the adhesive sheet (a) and (b) of the 2-2 of the present invention. It is sectional drawing of the sheet | seat for temporary fixing which can be used by 3rd this invention. It is a figure which shows a mode that the semiconductor wafer was affixed on the sheet | seat for temporary fixing. It is a figure which shows a mode that the adhesive bond layer was formed between the sheet | seat for temporary fixing, and the bevel part of a base. (A) is a figure which shows a mode that the adhesive bond layer was formed between the sheet | seat for temporary fixing, and the bevel part of a base. (B) is an enlarged view around the bevel portion of the pedestal. (A) is a figure which shows a mode that the adhesive bond layer was formed between the sheet | seat for temporary fixing, and the bevel part of a base. (B) is an enlarged view of the periphery of the bevel portion of the semiconductor wafer. It is a figure which shows a mode that it cut | incised into the sheet | seat for temporary fixing. It is sectional drawing of the sheet | seat for temporary fixing which has a recessed part. FIG. 4 is a schematic cross-sectional view of an adhesive sheet that can be used in (4-1) the present invention. FIG. 4 is a plan view of an adhesive sheet that can be used in the fourth embodiment of the present invention. FIG. 4 is a schematic cross-sectional view of an adhesive sheet that can be used in (4-1) the present invention. In the 4-1 of this invention, it is a schematic diagram which shows a mode that the semiconductor wafer was fixed to the base. In the 4-1 of this invention, it is a schematic diagram which shows a mode that the 1st adhesive bond layer was cut | disconnected. FIG. 4 is a schematic cross-sectional view of an adhesive sheet that can be used in the 4-2th invention. It is a top view of the adhesive sheet which can be used by the 4-2th this invention. FIG. 4 is a schematic cross-sectional view of an adhesive sheet that can be used in the 4-2th invention. In the 4-2th present invention, it is a mimetic diagram showing signs that the 1st adhesive layer was cut. It is a cross-sectional schematic diagram of an adhesive sheet that can be used in the 4th aspect of the present invention. It is a cross-sectional schematic diagram of an adhesive sheet that can be used in the 4th aspect of the present invention. In the 4th-3rd aspect of this invention, it is a schematic diagram which shows a mode that the semiconductor wafer was affixed on the adhesive sheet. FIG. 14 is a schematic diagram showing a state in which a semiconductor wafer is fixed to a pedestal in the fourth to third present invention. FIG. 6 is a schematic diagram showing a state in which a cut is made at the boundary between the first adhesive layer and the second layer in the fourth to third present invention. It is a cross-sectional schematic diagram of the adhesive sheet (a) that can be used in the 4th aspect of the present invention. It is a schematic diagram which shows a mode that the semiconductor wafer was affixed on the adhesive sheet (a). It is a cross-sectional schematic diagram of the adhesive sheet (b) that can be used in the 4th aspect of the present invention. It is a schematic diagram which shows a mode that the base was affixed on the adhesive sheet (b). It is a schematic diagram which shows a mode that the semiconductor wafer was fixed to the base using the adhesive sheets (a) and (b). It is a schematic diagram which shows a mode that it cut | incised into the boundary of an adhesive sheet (a) and an adhesive sheet (b). FIG. 6 is a cross-sectional view of a temporary fixing sheet that can be used in the fourth to fifth present inventions. It is a figure which shows a mode that the semiconductor wafer was affixed on the sheet | seat for temporary fixing. It is a figure which shows a mode that the adhesive layer for temporary fixing was formed between the sheet | seat for temporary fixing, and the bevel part of a base. (A) is a figure which shows a mode that the adhesive layer for temporary fixing was formed between the sheet | seat for temporary fixing, and the bevel part of a base. (B) is an enlarged view around the bevel portion of the pedestal. (A) is a figure which shows a mode that the adhesive layer for temporary fixing was formed between the sheet | seat for temporary fixing, and the bevel part of a base. (B) is an enlarged view of the periphery of the bevel portion of the semiconductor wafer. It is a figure which shows a mode that it cut | incised into the sheet | seat for temporary fixing. It is sectional drawing of the sheet | seat for temporary fixing which has a recessed part. It is sectional drawing of the adhesive sheet of Embodiment 1 of 5th this invention. It is a top view of the adhesive sheet of Embodiment 1 of the 5th present invention. It is a top view of the structure which has many through-holes. It is sectional drawing of an adhesive sheet provided with a 3rd layer. It is sectional drawing of the adhesive sheet of Embodiment 2 of 5th this invention. It is a top view of the adhesive sheet of Embodiment 2 of the 5th present invention. It is sectional drawing of the adhesive sheet of Embodiment 3 of 5th this invention. It is a schematic diagram which shows a mode that the semiconductor wafer was fixed to the base using the adhesive sheet of Embodiment 1 of 5th this invention.

<< First Present Invention >>
[Adhesive sheet]
The adhesive sheet for manufacturing a semiconductor device according to the first aspect of the present invention includes a first adhesive layer and a second layer having an adhesive force lower than that of the first adhesive layer, and at least the adhesive sheet for manufacturing a semiconductor device. A peripheral portion is formed by the first adhesive layer.

Hereinafter, the adhesive sheet of the first invention will be described with reference to the drawings.

FIG. 1 is a schematic cross-sectional view of the adhesive sheet 5 of the first embodiment. As shown in FIG. 1, the adhesive sheet 5 has a peripheral portion 54 formed of a first adhesive layer 50, and a central portion 53 inside the peripheral portion 54 has a first adhesive layer 50 and a second adhesive layer 50. It is formed by stacking with the layer 51. That is, the adhesive sheet 5 includes a second layer 51 and a first adhesive layer 50 that is laminated on the second layer 51 in such a manner as to cover the upper surface and side surfaces of the second layer 51. The adhesive force of the second layer 51 is lower than the adhesive force of the first adhesive layer 50.

The peripheral portion 54 of the adhesive sheet 5 is formed by the first adhesive layer 50. Since the first adhesive layer 50 having higher adhesive strength than the second layer 51 is present in the peripheral portion 54, the semiconductor wafer can be firmly fixed to the pedestal in this portion.
Moreover, since it has not only the 1st adhesive bond layer 50 but the 2nd layer 51 whose adhesive force is lower than the 1st adhesive bond layer 50, if even the adhesive force of the 1st adhesive bond layer 50 falls, it will be by external force. The pedestal can be easily separated from the semiconductor wafer.
Since the first adhesive layer 50 is formed in the peripheral portion 54 of the adhesive sheet 5 in the adhesive sheet 5, the first adhesive layer 50 is dissolved by a solvent, or physically cut by a cutter or a laser. And it is easy to reduce the adhesive force of the 1st adhesive bond layer 50, and it is easy to isolate | separate a base from a semiconductor wafer.

In the adhesive sheet 5, the central portion 53 inside the peripheral portion 54 is formed by stacking the first adhesive layer 50 and the second layer 51. The semiconductor wafer or the pedestal can be firmly fixed on the surface where only the first adhesive layer 50 is exposed. Further, since the central portion 53 is formed by stacking the first adhesive layer 50 and the second layer 51, the central portion 53 is more than the peripheral portion 54 formed by only the first adhesive layer 50. However, the adhesive strength is relatively low. Therefore, the base can be easily separated from the semiconductor wafer by an external force if the adhesive force of the peripheral portion 54 is reduced at least. Further, when the second layer 51 is in contact with the pedestal, the adhesive sheet 5 is easily peeled off from the pedestal, the adhesive residue is small, and the pedestal is easy to reuse.

The thickness of the adhesive sheet 5 is not specifically limited, For example, it is 10 micrometers or more, Preferably it is 50 micrometers or more. When the thickness is 10 μm or more, the unevenness on the surface of the semiconductor wafer device can be followed, and the adhesive sheet can be filled without a gap. Moreover, the thickness of the adhesive sheet 5 is 500 micrometers or less, for example, Preferably it is 300 micrometers or less. When the thickness is 500 μm or less, variation in thickness and shrinkage / expansion during heating can be suppressed or prevented.

Although the thickness of the 1st adhesive bond layer 50 in the center part 53 can be set suitably, Preferably it is 0.1 micrometer or more, More preferably, it is 0.5 micrometer or more, More preferably, it is 1 micrometer or more. Moreover, this thickness becomes like this. Preferably it is 300 micrometers or less, More preferably, it is 200 micrometers or less.
Further, the thickness of the second layer 51 in the central portion 53 can be set as appropriate.

Since the first adhesive layer generally has a lower elastic modulus than the second layer, undulation is likely to occur on the surface during formation. From such a viewpoint, it is preferable to make the first adhesive layer thinner and the second layer thicker. On the other hand, since the first adhesive layer generally has a higher glass transition temperature than the second layer, the shrinkage during formation is large. From such a viewpoint, it is preferable to make the first adhesive layer thick and the second layer thin.

FIG. 2 is a plan view of the adhesive sheet 5 of the first embodiment. As shown in FIG. 2, the adhesive sheet 5 has a circular shape when viewed in plan.
The diameter of the adhesive sheet 5 is not particularly limited. For example, the diameter of the adhesive sheet 5 is preferably +1.0 to −1.0 mm with respect to the diameter of the pedestal.

Further, when the adhesive sheet 5 is viewed in plan, the shape of the second layer 51 is circular. The area of the second layer 51 when the adhesive sheet 5 is viewed in plan is preferably 10% or more, more preferably 20% or more with respect to the area of the adhesive sheet 5 when the adhesive sheet 5 is viewed in plan. Preferably it is 50% or more. When it is 10% or more, the adhesive force of the first adhesive layer 50 formed on the peripheral portion 54 is likely to be reduced, and the pedestal is easily separated from the semiconductor wafer. The area of the second layer 51 is preferably 99.95% or less, more preferably 99.9% or less. A semiconductor wafer can be firmly fixed to a base as it is 99.95% or less.

The adhesive sheet of the first invention is not limited to the adhesive sheet 5 of the first embodiment. FIG. 3 is a schematic cross-sectional view of the adhesive sheet of the second embodiment. As shown in FIG. 3, in the adhesive sheet 6, the peripheral portion 64 is formed by the first adhesive layer 60, and the central portion 63 inside the peripheral portion 64 is formed by the second layer 61. . The adhesive force of the second layer 61 is lower than the adhesive force of the first adhesive layer 60.

In the adhesive sheet 6, a central portion 63 inside the peripheral portion 64 is formed by the second layer 61. Since the central portion 63 is formed of the second layer 61, if the adhesive force of the first adhesive layer 60 in the peripheral portion 64 is reduced, the pedestal can be easily separated from the semiconductor wafer by an external force. Further, since the second layer 61 is in contact with the pedestal, the adhesive sheet 6 is easily peeled off from the pedestal, the adhesive residue is small, and the pedestal is easy to reuse.

The thickness of the adhesive sheet 6 is not specifically limited, For example, it is the same as that of the adhesive sheet 5 of Embodiment 1.

FIG. 4 is a plan view of the adhesive sheet 6 according to the second embodiment. As shown in FIG. 4, the adhesive sheet 6 has a circular shape when viewed in plan. The diameter of the adhesive sheet 6 is not specifically limited, For example, it is the same as that of what was illustrated by the adhesive sheet 5 of Embodiment 1. FIG. Further, the area of the second layer 61 when the adhesive sheet 6 is viewed in plan is not particularly limited, and for example, is the same as that exemplified for the adhesive sheet 5 of the first embodiment.

The adhesive force of the second layers 51 and 61 is not particularly limited as long as it is lower than the adhesive force of the first

adhesive layers

50 and 60. The adhesive strength of the second layers 51 and 61 is preferably such that, for example, the 90 ° peel peeling force for a silicon wafer under the conditions of a temperature of 23 ± 2 ° C. and a peeling speed of 300 mm / min is less than 0.30 N / 20 mm. More preferably, it is 0.20 N / 20 mm or less. If it is less than 0.30 N / 20 mm, the second layers 51 and 61 can be easily peeled off. The lower limit of the 90 ° peel strength is not particularly limited, and is, for example, 0 N / 20 mm or more, preferably 0.001 N / 20 mm or more. The lower the 90 ° peel peel force, the easier the second layers 51 and 61 are peeled.

The adhesive strength of the first

adhesive layers

50 and 60 is, for example, that the 90 ° peel peel force for a silicon wafer under conditions of a temperature of 23 ± 2 ° C. and a peel speed of 300 mm / min is 0.30 N / 20 mm or more. Is preferable, and 0.40 N / 20 mm or more is more preferable. When it is 0.30 N / 20 mm or more, the semiconductor wafer can be favorably held on the pedestal, and back grinding and the like can be favorably performed. The upper limit of the 90 ° peel peel force is not particularly limited and is preferably as large as possible. For example, it is 30 N / 20 mm or less, preferably 20 N / 20 mm or less.

As shown in FIGS. 5 and 6, the adhesive sheet of the first aspect of the present invention may have other layers formed thereon. 5 and 6 are schematic cross-sectional views of an adhesive sheet including a third layer. In the adhesive sheet 5 of FIG. 5, a third layer 55 is formed across the peripheral portion 54 and the central portion 53. In the adhesive sheet 6 of FIG. 6, a third layer 65 is formed across the peripheral portion 64 and the central portion 63. Adhesive sheet with the third layers 55 and 65 from the semiconductor wafer by affixing the surface on which the third layers 55 and 65 having lower adhesive strength than the first

adhesive layers

50 and 60 are exposed to the semiconductor wafer. 5 and 6 can be easily peeled off. Further, the adhesive residue on the semiconductor wafer can be eliminated, and the semiconductor wafer cleaning step can be omitted.

The adhesive force of the third layers 55 and 65 is not particularly limited as long as it is lower than the adhesive force of the first

adhesive layers

50 and 60. For example, the 90 ° peel peeling force for a silicon wafer under conditions of a temperature of 23 ± 2 ° C. and a peeling speed of 300 mm / min is preferably less than 0.30 N / 20 mm, and preferably 0.20 N / 20 mm or less. More preferred. When the thickness is less than 0.30 N / 20 mm, the adhesive can be peeled without residue, and the semiconductor wafer cleaning process can be omitted. Moreover, the minimum of this 90 degree peeling force is not specifically limited, For example, it is 0 N / 20mm or more, Preferably it is 0.001 N / 20mm or more. A semiconductor wafer can be favorably hold | maintained to a base as it is 0 N / 20mm or more.

As long as it selects so that the adhesive force of the 1st adhesive bond layers 50 and 60 may become higher than the adhesive force of the 2nd layers 51 and 61 as an adhesive composition which comprises the 1st adhesive bond layers 50 and 60. There is no particular limitation.

As the adhesive composition constituting the first

adhesive layers

50 and 60, a polyimide resin having an imide group and having a structural unit derived from a diamine having an ether structure at least partially can be used. Moreover, a silicone resin can also be used suitably. Especially, the said polyimide resin is preferable from the point of heat resistance, chemical resistance, and adhesive residue.

The polyimide resin can be generally obtained by imidizing (dehydrating and condensing) a polyamic acid that is a precursor thereof. As a method for imidizing the polyamic acid, for example, a conventionally known heat imidization method, azeotropic dehydration method, chemical imidization method and the like can be employed. Of these, the heating imidization method is preferable. When the heat imidization method is employed, it is preferable to perform heat treatment under a nitrogen atmosphere or an inert atmosphere such as a vacuum in order to prevent deterioration of the polyimide resin due to oxidation.

The polyamic acid is charged in an appropriately selected solvent such that an acid anhydride and a diamine (including both a diamine having an ether structure and a diamine not having an ether structure) have a substantially equimolar ratio. Can be obtained by reaction.

The diamine having an ether structure is not particularly limited as long as it is a compound having an ether structure and having at least two terminals having an amine structure. Examples thereof include diamine having a glycol skeleton.

Examples of the diamine having a glycol skeleton include a polypropylene glycol structure and a diamine having one amino group at each end, a polyethylene glycol structure, and one amino group at each end. Examples thereof include a diamine having a polytetramethylene glycol structure and a diamine having an alkylene glycol such as a diamine having one amino group at each end. Moreover, the diamine which has two or more of these glycol structures and has one amino group in both the ends can be mentioned.

The molecular weight of the diamine having an ether structure is preferably in the range of 100 to 5000, and more preferably 150 to 4800. When the molecular weight of the diamine having an ether structure is in the range of 100 to 5,000, the first

adhesive layers

50 and 60 having high adhesive strength at low temperatures and exhibiting peelability at high temperatures are easily obtained.

In the formation of the polyimide resin, a diamine having no ether structure can be used in combination with a diamine having an ether structure. Examples of the diamine having no ether structure include aliphatic diamines and aromatic diamines. By using a diamine having no ether structure in combination, the adhesion with the adherend can be controlled. The mixing ratio of the diamine having an ether structure and the diamine having no ether structure is preferably in the range of 100: 0 to 10:90, more preferably 100: 0 to 20: 80, more preferably 99: 1 to 30:70. When the mixing ratio of the diamine having an ether structure and the diamine having no ether structure is in the range of 100: 0 to 10:90 in terms of molar ratio, the thermal peelability at high temperature is excellent.

Examples of the aliphatic diamine include ethylenediamine, hexamethylenediamine, 1,8-diaminooctane, 1,10-diaminodecane, 1,12-diaminododecane, 4,9-dioxa-1,12-diaminododecane, , 3-bis (3-aminopropyl) -1,1,3,3-tetramethyldisiloxane (α, ω-bisaminopropyltetramethyldisiloxane) and the like. The molecular weight of the aliphatic diamine is usually 50 to 1,000,000, preferably 100 to 30,000.

Examples of the aromatic diamine include 4,4′-diaminodiphenyl ether, 3,4′-diaminodiphenyl ether, 3,3′-diaminodiphenyl ether, m-phenylenediamine, p-phenylenediamine, and 4,4′-diaminodiphenylpropane. 3,3'-diaminodiphenylmethane, 4,4'-diaminodiphenyl sulfide, 3,3'-diaminodiphenyl sulfide, 4,4'-diaminodiphenyl sulfone, 3,3'-diaminodiphenyl sulfone, 1,4-bis (4-aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene, 1,3-bis (3-aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) -2,2- Dimethylpropane, 4,4'-diaminobenzophenone, etc. It is. The molecular weight of the aromatic diamine is usually 50 to 1000, preferably 100 to 500. The molecular weight of the aliphatic diamine and the molecular weight of the aromatic diamine are values measured by GPC (gel permeation chromatography) and calculated in terms of polystyrene (weight average molecular weight).

Examples of the acid anhydride include 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, 2,2 ′, 3,3′-biphenyltetracarboxylic dianhydride, 3,3 ′, 4,4′-benzophenone tetracarboxylic dianhydride, 2,2 ′, 3,3′-benzophenone tetracarboxylic dianhydride, 4,4′-oxydiphthalic dianhydride, 2,2-bis (2, 3-Dicarboxyphenyl) hexafluoropropane dianhydride, 2,2-bis (3,4-dicarboxyphenyl) hexafluoropropane dianhydride (6FDA), bis (2,3-dicarboxyphenyl) methane dianhydride Bis (3,4-dicarboxyphenyl) methane dianhydride, bis (2,3-dicarboxyphenyl) sulfone dianhydride, bis (3,4-dicarboxyphenyl) sulfone Anhydride, pyromellitic dianhydride, ethylene glycol bis trimellitic dianhydride and the like. These may be used alone or in combination of two or more.

Examples of the solvent for reacting the acid anhydride with the diamine include N, N-dimethylacetamide, N-methyl-2-pyrrolidone, N, N-dimethylformamide, and cyclopentanone. These may be used alone or in combination. Further, in order to adjust the solubility of raw materials and resins, a nonpolar solvent such as toluene or xylene may be appropriately mixed and used.

Examples of the silicone resin include peroxide cross-linked silicone pressure-sensitive adhesives, addition reaction type silicone pressure-sensitive adhesives, dehydrogenation reaction type silicone pressure-sensitive adhesives, and moisture-curing type silicone pressure-sensitive adhesives. The said silicone resin may be used individually by 1 type, and may use 2 or more types together. When the silicone resin is used, the heat resistance becomes high, and the storage elastic modulus and adhesive strength at high temperatures can be appropriate values. Among the silicone resins, addition reaction type silicone pressure-sensitive adhesives are preferable in terms of few impurities.

The adhesive composition constituting the first

adhesive layers

50 and 60 may contain other additives. Examples of such other additives include flame retardants, silane coupling agents, and ion trapping agents. Examples of the flame retardant include antimony trioxide, antimony pentoxide, and brominated epoxy resin. Examples of the silane coupling agent include β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, and the like. Examples of the ion trapping agent include hydrotalcites and bismuth hydroxide. Such other additives may be only one kind or two or more kinds.

The material constituting the second layers 51 and 61 is not particularly limited as long as the second layers 51 and 61 are selected so that the adhesive strength of the second layers 51 and 61 is lower than the adhesive strength of the first

adhesive layers

50 and 60. . Examples of the material constituting the second layers 51 and 61 include inorganic materials such as Cu, Cr, Ni, and Ti. Moreover, the above-mentioned polyimide resin and the above-mentioned silicone resin can also be used.

The material constituting the third layers 55 and 65 is not particularly limited as long as the adhesive force of the third layers 55 and 65 is selected to be lower than the adhesive force of the first

adhesive layers

50 and 60. For example, the same layer as the second layers 51 and 61 can be used.

(Manufacture of adhesive sheets)
The adhesive sheet 5 is produced as follows, for example. First, a solution containing a material for forming the second layer 51 is prepared. Next, the solution is applied to a base material so as to have a predetermined thickness to form a coating film, and then the coating film is dried under predetermined conditions to form the second layer 51. Examples of the substrate include metal foil such as SUS304, 6-4 alloy, aluminum foil, copper foil, Ni foil, polyethylene terephthalate (PET), polyethylene, polypropylene, fluorine-based release agent, and long-chain alkyl acrylate-type release agent. A plastic film, paper, or the like whose surface is coated with a release agent such as, can be used. Moreover, it does not specifically limit as a coating method, For example, roll coating, screen coating, gravure coating, spin coat coating etc. are mentioned.

Next, by punching or the like from the second layer 51 side, it is punched into a predetermined shape (for example, circular, rectangular, etc.), leaving a punched portion (second layer 51 of circular shape, rectangular shape, etc.) Remove the outside.

On the other hand, a solution containing a composition for forming the first adhesive layer 50 is prepared.

Next, a solution containing a composition for forming the first adhesive layer 50 is formed on the substrate on which the second layer 51 punched into a predetermined shape is laminated. A coating film is formed by coating from the side 51 to a predetermined thickness. Thereafter, the coating film is dried under predetermined conditions to form the first adhesive layer 50. From the above, the adhesive sheet 5 shown in FIGS. Note that the adhesive sheet 6 shown in FIGS. 3 and 4 can be formed by a method substantially similar to that of the adhesive sheet 5.

The third layers 55 and 65 shown in FIGS. 5 and 6 can be formed by the same method as the second layer 51.

In the above description, the

adhesive sheets

5 and 6 having a circular shape when viewed in plan have been described. However, the shape is not particularly limited, and may be another shape such as a polygon or an ellipse.

In addition, the

adhesive sheets

5 and 6 in which the shapes of the second layers 51 and 61 are circular when viewed in plan have been described. However, the shape is not particularly limited, and may be another shape such as a polygon or an ellipse.

The adhesive sheet for manufacturing a semiconductor device according to the first aspect of the present invention is used for fixing a semiconductor wafer to a pedestal. Specifically, it can be suitably used in a semiconductor device manufacturing method described later.

[Method for Manufacturing Semiconductor Device]
The manufacturing method of the semiconductor device of 1st this invention includes the process of fixing a semiconductor wafer to a base using an adhesive sheet, and the process of isolate | separating a base from a semiconductor wafer. For example, there is a method including a step of fixing a semiconductor wafer to a pedestal using an adhesive sheet, a step of back grinding the semiconductor wafer, and a step of separating the pedestal from the back-ground semiconductor wafer.

In the following description, the case where the adhesive sheet 5 of Embodiment 1 is used will be described. FIG. 7 is a schematic diagram illustrating a state in which the semiconductor wafer is fixed to the pedestal using the adhesive sheet of the first embodiment.

First, a process of fixing the semiconductor wafer 3 to the base 1 using the adhesive sheet 5 is performed. Specifically, the surface of the adhesive sheet 5 on which the first adhesive layer 50 and the second layer 51 are exposed is attached to the base 1, and only the first adhesive layer 50 of the adhesive sheet 5 is exposed. The surface is attached to the circuit forming surface of the semiconductor wafer 3.

The semiconductor wafer 3 is not particularly limited, and examples thereof include a compound semiconductor wafer such as a germanium wafer, a gallium-arsenic wafer, a gallium-phosphorus wafer, a gallium-arsenic-aluminum wafer, and a sapphire wafer. Among these, a silicon wafer is preferable.

A semiconductor wafer 3 having a circuit forming surface and a non-circuit forming surface is used. Moreover, what has a through silicon via (through-silicon via) can be used conveniently. This is because a silicon wafer having through silicon vias is usually thinned by back grinding, which will be described later, so that it is desirable to fix the silicon wafer to the pedestal 1 and reinforce the strength.

The thickness of the semiconductor wafer 3 is not particularly limited, but is, for example, 400 to 1200 μm, preferably 450 to 1000 μm.

The diameter of the semiconductor wafer 3 is not particularly limited, but is, for example, 75 to 450 mm. As such a semiconductor wafer 3, a commercially available 200 mm wafer, 300 mm wafer, or the like can be used.

The pedestal 1 is not particularly limited, and examples thereof include compound wafers such as silicon wafers, SiC wafers, and GaAs wafers, glass wafers, metal foils such as SUS, 6-4 Alloy, Ni foil, and Al foil. In the case of adopting a round shape in plan view, a silicon wafer or a glass wafer is preferable. Moreover, when it is a rectangle by planar view, a SUS board or a glass plate is preferable.

Moreover, as the base 1, for example, low density polyethylene, linear polyethylene, medium density polyethylene, high density polyethylene, ultra low density polyethylene, random copolymer polypropylene, block copolymer polypropylene, homopolyprolene, polybutene, polymethylpentene, etc. Polyolefin, ethylene-vinyl acetate copolymer, ionomer resin, ethylene- (meth) acrylic acid copolymer, ethylene- (meth) acrylic acid ester (random, alternating) copolymer, ethylene-butene copolymer, ethylene -Hexene copolymers, polyesters such as polyurethane, polyethylene terephthalate, polyethylene naphthalate, polycarbonate, polyimide, polyetheretherketone, polyimide, polyetherimide, polyamide, wholly aromatic polyamide Polyphenyl sulphates id, aramid (paper), can be glass, glass cloth, fluorine resin, polyvinyl chloride, polyvinylidene chloride, cellulose resin, silicone resin, also possible to use paper or the like.

The pedestal 1 may be used alone or in combination of two or more. The thickness of the pedestal 1 is not particularly limited, but is usually about 10 μm to 20 mm, for example.

The diameter of the pedestal 1 is not particularly limited, but is, for example, 75 to 450 mm, and preferably 100 to 450 mm. As such a pedestal 1, a commercially available 200 mm wafer, 300 mm wafer, or the like can be used.

The method of attaching (fixing) is not particularly limited, but pressure bonding is preferable. The crimping is usually performed while pressing with a pressing means such as a crimping roll. As the pressure bonding conditions, for example, 20 to 300 ° C., 0.001 to 10 MPa, and 0.001 to 10 mm / sec are preferable. The crimping time is usually 0.1 to 10 minutes.
After the pressure bonding, the first adhesive layer 50 and the second layer 51 are imidized as necessary. Thereby, the semiconductor wafer 3 can be favorably fixed to the base 1. Imidization can be performed by a conventionally known method, for example, imidization can be performed under conditions of 150 to 500 ° C. and 0.5 to 5 hours. Only one of the first adhesive layer 50 and the second layer 51 may be imidized.

Next, the semiconductor wafer 3 is back-ground. The back grinding can be performed by a conventionally known method.

The thickness of the back-ground semiconductor wafer is, for example, 1 to 300 μm, and preferably 5 to 100 μm.

After the back grinding, the non-circuit forming surface (the back ground surface) of the semiconductor wafer 3 can be processed. Examples of processing methods include electrode formation, metal wiring formation, and protective film formation. Note that a through silicon via may be formed by the processing.

After back grinding and processing, the pedestal 1 is separated from the semiconductor wafer 3.

A method for separating the pedestal 1 from the semiconductor wafer 3 is not particularly limited, but it is preferable to separate the pedestal 1 after reducing the adhesive force of the first adhesive layer 50 in the peripheral portion 54. Thereby, it can isolate | separate easily. As a method of reducing the adhesive force of the first adhesive layer 50, a method of lowering the adhesive force by dissolving the first adhesive layer 50 with a solvent, a physical method using a cutter, a laser, or the like is applied to the first adhesive layer 50. Examples thereof include a method of reducing the adhesive force by cutting a slit, a method of forming the first adhesive layer 50 with a material whose adhesive force is reduced by heating, and a method of reducing the adhesive force by heating.

In the above description, as a method of fixing the semiconductor wafer 3 to the pedestal 1 using the adhesive sheet 5, the surfaces of the adhesive sheet 5 on which the first adhesive layer 50 and the second layer 51 are exposed are pasted on the pedestal 1. The method of attaching the surface of the adhesive sheet 5 where only the first adhesive layer 50 is exposed to the circuit forming surface of the semiconductor wafer 3 has been described. However, the method of fixing the semiconductor wafer 3 to the pedestal 1 using the adhesive sheet 5 is not particularly limited, and the surface of the adhesive sheet 5 on which only the first adhesive layer 50 is exposed is attached to the pedestal 1 and the adhesive sheet is attached. 5 may be a method in which the surface on which the first adhesive layer 50 and the second layer 51 are exposed is attached to the circuit forming surface of the semiconductor wafer 3.

Further, the case where the semiconductor wafer 3 having a circuit forming surface and a non-circuit forming surface is used has been described. However, it is not limited to those having a circuit formation surface and a non-circuit formation surface, and both surfaces may be those having a non-circuit formation surface.

Further, the case where the semiconductor wafer 3 fixed to the base 1 is back-ground has been described. However, back grinding is not essential, and the semiconductor wafer 3 may be processed without back grinding.

<< Second Invention >>
Hereinafter, the second aspect of the present invention (the 2-1 aspect of the present invention and the 2-2 aspect of the present invention) will be described while referring to differences from the first aspect of the present invention.

A second object of the present invention is to provide an adhesive sheet for manufacturing a semiconductor device that can satisfactorily fix a semiconductor wafer to a pedestal and easily separate the pedestal from the semiconductor wafer. A second object of the present invention is to provide a method for manufacturing a semiconductor device in which a semiconductor wafer can be satisfactorily fixed to a pedestal and the pedestal can be easily separated from the semiconductor wafer.

[Adhesive sheet]
In the adhesive sheet for manufacturing a semiconductor device according to the 2-1 of the present invention, a first adhesive layer and a second layer having an adhesive strength lower than that of the first adhesive layer are laminated.

The 2-1 adhesive sheet of the present invention will be described below with reference to the drawings.

FIG. 8 is a schematic cross-sectional view of the adhesive sheet 7 of the first embodiment. As shown in FIG. 8, the adhesive sheet 7 is formed by laminating a first adhesive layer 70 and a second layer 71. The adhesive force of the second layer 71 is lower than the adhesive force of the first adhesive layer 70.

Since the adhesive sheet 7 has the first adhesive layer 70, the semiconductor wafer can be satisfactorily fixed to the pedestal. Moreover, since it has the 2nd layer 71 whose adhesive force is lower than the 1st adhesive bond layer 70, a base can be easily isolate | separated from a semiconductor wafer with external force.

The thickness of the 1st adhesive bond layer 70 is not specifically limited, For example, it is 10 micrometers or more, Preferably it is 50 micrometers or more. When the thickness is 10 μm or more, the unevenness on the surface of the semiconductor wafer can be followed, and the adhesive sheet 7 can be filled without a gap. Moreover, the thickness of the 1st adhesive bond layer 70 is 500 micrometers or less, for example, Preferably it is 300 micrometers or less. When the thickness is 500 μm or less, variation in thickness and shrinkage / expansion during heating can be suppressed or prevented.

The thickness of the 2nd layer 71 is not specifically limited, For example, it is 1 micrometer or more, Preferably it is 5 micrometers or more. When it is 1 μm or more, it is easy to bond to the pedestal. The thickness of the second layer 71 is, for example, 500 μm or less, and preferably 300 μm or less. When the thickness is 500 μm or less, variation in thickness and shrinkage / expansion during heating can be suppressed or prevented.

The shape of the adhesive sheet 7 when viewed from above is not particularly limited, but is usually circular.

The adhesive force of the second layer 71 is not particularly limited as long as it is lower than the adhesive force of the first adhesive layer 70. The adhesive strength of the second layer 71 is preferably, for example, a 90 ° peel peel force for a silicon wafer under a temperature of 23 ± 2 ° C. and a peel speed of 300 mm / min is less than 0.30 N / 20 mm. More preferably, it is 20 N / 20 mm or less. When it is less than 0.30 N / 20 mm, the pedestal can be easily separated from the semiconductor wafer. On the other hand, the lower limit of the 90 ° peel strength is preferably 0.001 N / 20 mm or more, more preferably 0.005 N / 20 mm or more, and still more preferably 0.010 N / 20 mm or more. When it is 0.001 N / 20 mm or more, the semiconductor wafer can be fixed to the pedestal well, and back grinding and the like can be performed well.

The adhesive force of the first adhesive layer 70 is preferably, for example, a 90 ° peel peel force for a silicon wafer under conditions of a temperature of 23 ± 2 ° C. and a peel speed of 300 mm / min is 0.30 N / 20 mm or more. 0.40 N / 20 mm or more is more preferable. When it is 0.30 N / 20 mm or more, the semiconductor wafer can be satisfactorily fixed to the pedestal, and back grinding and the like can be favorably performed. The upper limit of the 90 ° peel peel force is not particularly limited and is preferably as large as possible. For example, it is 30 N / 20 mm or less, preferably 20 N / 20 mm or less.

As shown in FIG. 9, the adhesive sheet of the 2-1st invention may be one in which other layers are formed (Embodiment 2). FIG. 9 is a schematic cross-sectional view of an adhesive sheet including a third layer. The adhesive sheet 7 of FIG. 9 is formed by stacking a third layer 75, a second layer 71, and a first adhesive layer 70.

The adhesive force of the third layer 75 is preferably lower than the adhesive force of the first adhesive layer 70. Thereby, when the 3rd layer 75 of the adhesive sheet 7 is affixed on a base, the adhesive sheet 7 can be easily peeled from a base. Further, the adhesive residue on the pedestal can be eliminated, and the pedestal cleaning step can be omitted.

The adhesive strength of the third layer 75 is preferably such that the 90 ° peel peel force for a silicon wafer under the conditions of a temperature of 23 ± 2 ° C. and a peel rate of 300 mm / min is less than 0.30 N / 20 mm. More preferably, it is 20 N / 20 mm or less. The adhesive sheet 7 can be peeled easily as it is less than 0.30 N / 20 mm. Further, the adhesive residue on the pedestal and the like can be eliminated, and the cleaning process for the pedestal and the like can be omitted. On the other hand, the lower limit of the 90 ° peel peel force is preferably 0.001 N / 20 mm or more. When it is 0.001 N / 20 mm or more, the semiconductor wafer can be fixed to the pedestal well, and back grinding and the like can be performed well.

The adhesive composition constituting the first adhesive layer 70 is not particularly limited as long as it is selected so that the adhesive force of the first adhesive layer 70 is higher than the adhesive force of the second layer 71. As the adhesive composition constituting the first adhesive layer 70, the polyimide resin and the silicone resin described in the first aspect of the present invention can be suitably used. Of these, polyimide resins are preferred from the viewpoints of heat resistance, chemical resistance, and adhesive residue.

The material constituting the second layer 71 is not particularly limited as long as it is selected so that the adhesive force of the second layer 71 is lower than the adhesive force of the first adhesive layer 70. As a material constituting the second layer 71, the aforementioned polyimide resin and the aforementioned silicone resin can also be used. Especially, the said polyimide resin is preferable from the point of heat resistance, chemical resistance, and adhesive residue.

The material constituting the third layer 75 is not particularly limited as long as the material is selected so that the adhesive force of the third layer 75 is lower than the adhesive force of the first adhesive layer 70. What was illustrated by the layer 71 of this is mentioned.

(Manufacture of adhesive sheets)
The adhesive sheet 7 is produced as follows, for example. First, a solution containing a material for forming the second layer 71 is prepared. Next, the solution is applied on a substrate so as to have a predetermined thickness to form a coating film, and then the coating film is dried under predetermined conditions to form the second layer 71. Examples of the substrate include metal foil such as SUS304, 6-4 alloy, aluminum foil, copper foil, Ni foil, polyethylene terephthalate (PET), polyethylene, polypropylene, fluorine-based release agent, and long-chain alkyl acrylate-type release agent. A plastic film, paper, or the like whose surface is coated with a release agent such as, can be used. Moreover, it does not specifically limit as a coating method, For example, roll coating, screen coating, gravure coating, spin coat coating etc. are mentioned.

On the other hand, a solution containing a composition for forming the first adhesive layer 70 is prepared.

Next, a solution containing a composition for forming the first adhesive layer 70 is formed on the base material on which the second layer 71 is laminated to a predetermined thickness from the second layer 71 side. In this way, a coating film is formed. Thereafter, the coating film is dried under predetermined conditions to form the first adhesive layer 70. From the above, the adhesive sheet 7 shown in FIG. 8 is obtained.

Note that the third layer 75 illustrated in FIG. 9 can be formed by a method similar to that of the second layer 71.

The 2-1 adhesive sheet for manufacturing a semiconductor device of the present invention is used for fixing a semiconductor wafer to a pedestal. Specifically, it can be suitably used in the 2-1 semiconductor device manufacturing method of the present invention described later.

[Method for Manufacturing Semiconductor Device]
A 2-1 semiconductor device manufacturing method of the present invention includes a step of fixing a semiconductor wafer to a pedestal using an adhesive sheet and a step of separating the pedestal from the semiconductor wafer. As such a method, for example, the step of fixing the semiconductor wafer to the pedestal by attaching the semiconductor wafer to the first adhesive layer and attaching the pedestal to the second layer, and the step of separating the pedestal from the semiconductor wafer The method containing these is mentioned. In the case of the method, the first adhesive layer can follow the irregularities on the surface of the semiconductor wafer, and the semiconductor wafer can be fixed to the pedestal satisfactorily. On the other hand, since the 2nd layer whose adhesive force is lower than a 1st adhesive bond layer contacts a base, it is easy to peel an adhesive sheet from a base. In addition, there is little adhesive residue on the pedestal and it is easy to reuse the pedestal.

In the following description, the case where the adhesive sheet 7 of Embodiment 1 is used will be described. FIG. 10 is a schematic diagram illustrating a state in which a semiconductor wafer is attached to the adhesive sheet of the first embodiment. FIG. 11 is a schematic diagram illustrating a state in which the semiconductor wafer is fixed to the pedestal using the adhesive sheet of the first embodiment.

First, the circuit formation surface of the semiconductor wafer 3 and the first adhesive layer 70 are bonded together (FIG. 10).

As the semiconductor wafer 3, the semiconductor wafer 3 described in the first aspect of the present invention can be preferably used.

The bonding method (sticking method) is not particularly limited, and examples thereof include a method of bonding at 23 to 250 ° C. and 0.01 to 10 MPa.
In addition, what is necessary is just to cut the adhesive sheet 7 before bonding or after bonding as needed, when the area of the adhesive sheet 7 is larger than the area of the semiconductor wafer 3.

Next, the base 1 and the second layer 71 are bonded together (FIG. 11).

As the pedestal 1, the pedestal 1 described in the first aspect of the present invention can be suitably used.

The bonding method (sticking method) is not particularly limited, and examples thereof include a method of bonding at 23 to 250 ° C. and 0.01 to 10 MPa.
In addition, what is necessary is just to cut the adhesive sheet 7 as needed, when the area of the adhesive sheet 7 is larger than the area of the base 1. FIG.

After bonding, the first adhesive layer 70 and the second layer 71 are imidized as necessary. Thereby, the semiconductor wafer 3 can be favorably fixed to the base 1. Imidization can be performed by a conventionally known method, for example, imidization can be performed under conditions of 150 to 500 ° C. and 0.5 to 5 hours. Only one of the first adhesive layer 70 and the second layer 71 may be imidized.

In addition, after bonding, the first adhesive layer 70 and the second layer 71 may be thermoset as necessary. When a silicone resin is used as the first adhesive layer 70 and the second layer 71, the semiconductor wafer 3 can be satisfactorily fixed to the base 1 by thermosetting. Only one of the first adhesive layer 70 and the second layer 71 may be thermally cured.

Subsequently, the semiconductor wafer 3 fixed to the base 1 can be back-ground. The back grinding can be performed by a conventionally known method.

After performing desired processing such as back grinding and processing on the semiconductor wafer 3, the pedestal 1 is separated from the semiconductor wafer 3.

The method for separating the pedestal 1 from the semiconductor wafer 3 is not particularly limited, and examples thereof include a method of applying an external force. Specifically, a method of separating only the pedestal 1, a method of separating the second layer 71 with the pedestal 1, and the like can be given. In addition, a method of cutting and separating the boundary between the first adhesive layer 70 and the second layer 71 is also suitable.

Note that the base 1 may be separated from the semiconductor wafer 3 after the adhesive force of the first adhesive layer 70 is reduced. As a method of reducing the adhesive force of the first adhesive layer 70, a method of lowering the adhesive force by dissolving the first adhesive layer 70 with a solvent, the first adhesive layer 70 is physically applied with a cutter or a laser. The first adhesive layer 70 is made of a material whose adhesive strength is reduced by heating, and the adhesive strength is reduced by heating, and heating in the presence of a surfactant. A method of ultrasonic cleaning, a method of penetrating a chemical solution into the first adhesive layer 70 (for example, a method of performing SC-1 cleaning, a method of penetrating a solution such as N-methyl-2-pyrrolidone), etc. Can be mentioned.

In the above description, the method of attaching the semiconductor wafer 3 to the first adhesive layer 70 and attaching the pedestal 1 to the second layer 71 has been described. However, the present invention is not limited to this, and the base 1 may be attached to the first adhesive layer 70 and the semiconductor wafer 3 may be attached to the second layer 71.

[Manufacturing method of other semiconductor device]
The manufacturing method of the semiconductor device according to 2-2 of the present invention includes a step (A) of attaching a semiconductor wafer to the adhesive sheet (a), a step (B) of attaching a pedestal to the adhesive sheet (b), and the above steps. The adhesive sheet (a) of the semiconductor wafer with the adhesive sheet (a) obtained by (A) and the adhesive sheet (b) of the base with the adhesive sheet (b) obtained by the step (B) are bonded together. Step (C). Moreover, one adhesive force of the said adhesive sheet (a) and (b) is lower than the other.

Since one adhesive force of the adhesive sheets (a) and (b) is lower than the other, the pedestal is easily separated from the semiconductor wafer. In addition, since the adhesive sheet having a relatively high adhesive force is used, the semiconductor wafer can be satisfactorily fixed to the pedestal.

It is preferable that the adhesive strength of the adhesive sheet (b) is lower than that of the adhesive sheet (a). In this case, the adhesive sheet (a) has a higher adhesive force than the adhesive sheet (b), and is excellent in irregularity followability on the surface of the semiconductor wafer and the like. Therefore, since the adhesive sheet (a) can follow the irregularities on the surface of the semiconductor wafer, the semiconductor wafer can be satisfactorily fixed to the pedestal. On the other hand, since the adhesive sheet (b) having an adhesive force lower than that of the adhesive sheet (a) is in contact with the pedestal, the adhesive sheet (b) is easily peeled from the pedestal. In addition, there is little adhesive residue on the pedestal and it is easy to reuse the pedestal.

In the following description, a case where the adhesive strength of the adhesive sheet (b) is lower than that of the adhesive sheet (a) will be described.

Hereinafter, a method for manufacturing a semiconductor device according to the 2-2 of the present invention will be described with reference to the drawings.
FIG. 12 is a schematic cross-sectional view of the adhesive sheet (a). FIG. 13 is a schematic view showing a state in which a semiconductor wafer is attached to the adhesive sheet (a). FIG. 14 is a schematic cross-sectional view of the adhesive sheet (b). FIG. 15 is a schematic view showing a state in which a pedestal is attached to the adhesive sheet (b). FIG. 16 is a schematic diagram showing a state in which the semiconductor wafer is fixed to the pedestal using the adhesive sheets (a) and (b).

Step (A)
In the step (A), the semiconductor wafer 4 is bonded to the adhesive sheet (a) 13 (FIG. 13).

First, the adhesive sheet (a) 13 will be described. As shown in FIG. 12, the adhesive sheet (a) 13 has a substrate 12 on one side and a separator 14 on the other side.

Although it does not specifically limit as an adhesive composition which comprises the adhesive sheet (a) 13, What was illustrated by the 1st adhesive bond layer 70 is suitable.

The adhesive strength of the adhesive sheet (a) 13 is preferably, for example, a 90 ° peel peel force for a silicon wafer under conditions of a temperature of 23 ± 2 ° C. and a peel speed of 300 mm / min is 0.30 N / 20 mm or more. 0.40 N / 20 mm or more is more preferable. When it is 0.30 N / 20 mm or more, the semiconductor wafer 4 can be fixed to the pedestal satisfactorily and back grinding can be performed well. The upper limit of the 90 ° peel peel force is not particularly limited and is preferably as large as possible. For example, it is 30 N / 20 mm or less, preferably 20 N / 20 mm or less.

As the substrate 12, metal foil such as SUS304, 6-4 alloy, aluminum foil, copper foil, Ni foil, polyethylene terephthalate (PET), polyethylene, polypropylene, fluorine release agent, long chain alkyl acrylate release agent Examples thereof include a plastic film or paper whose surface is coated with a release agent such as

Examples of the separator 14 include plastic film and paper whose surface is coated with a release agent such as polyethylene terephthalate (PET), polyethylene, polypropylene, a fluorine release agent, and a long-chain alkyl acrylate release agent.

It does not specifically limit as the semiconductor wafer 4, The semiconductor wafer 3 demonstrated by 1st this invention can be used conveniently.

In step A, the separator 14 is peeled off, and the semiconductor wafer 4 is attached to the adhesive sheet (a) 13.

The attaching method is not particularly limited, and examples thereof include a method of attaching at 23 to 250 ° C. and 0.01 to 10 MPa.
In addition, when the area of the adhesive sheet (a) 13 is larger than the area of the semiconductor wafer 4, the adhesive sheet (a) 13 may be cut as necessary before or after the attachment.

Process (B)
At a process (B), the base 2 is affixed on the adhesive sheet (b) 23 (FIG. 15).

As shown in FIG. 14, the adhesive sheet (b) 23 has a base material 22 on one side and a separator 24 on the other side.

Although it does not specifically limit as an adhesive composition which comprises the adhesive sheet (b) 23, What was illustrated by the 2nd layer 71 is suitable.

The adhesive strength of the adhesive sheet (b) 23 is preferably such that, for example, the 90 ° peel peel force for a silicon wafer under the conditions of a temperature of 23 ± 2 ° C. and a peel rate of 300 mm / min is less than 0.30 N / 20 mm, More preferably, it is 0.20 N / 20 mm or less. If it is less than 0.30 N / 20 mm, the base 2 can be easily separated from the semiconductor wafer 4. On the other hand, the lower limit of the 90 ° peel strength is preferably 0.001 N / 20 mm or more, more preferably 0.005 N / 20 mm or more, and still more preferably 0.010 N / 20 mm or more. When it is 0.001 N / 20 mm or more, the semiconductor wafer 4 can be fixed to the base 2 satisfactorily, and back grinding and the like can be performed satisfactorily.

It does not specifically limit as the base material 22, What was illustrated by the base material 12 etc. are mentioned. It does not specifically limit as the separator 24, What was illustrated by the separator 14 etc. are mentioned.

The pedestal 2 is not particularly limited, and the pedestal 1 described in the first aspect of the present invention can be suitably used.

In step B, the separator 24 is peeled off, and the base 2 is attached to the adhesive sheet (b) 23.

The attaching method is not particularly limited, and examples thereof include a method of attaching at 23 to 250 ° C. and 0.01 to 10 MPa.
When the area of the adhesive sheet (b) 23 is larger than the area of the pedestal 2, the adhesive sheet (b) 23 may be cut before or after application as necessary.

Process (C)
In the step (C), the adhesive sheet (a) 13 of the semiconductor wafer 4 with the adhesive sheet (a) 13 obtained in the step (A) and the base 2 with the adhesive sheet (b) 23 obtained in the step (B). The adhesive sheet (b) 23 is bonded together (FIG. 16). Thereby, the semiconductor wafer 4 can be fixed to the base 2.

The bonding method is not particularly limited. After bonding, the adhesive sheet (a) 13 and the adhesive sheet (b) 23 are imidized as necessary. Thereby, the semiconductor wafer 4 can be favorably fixed to the base 2. Imidization can be performed by a conventionally known method, for example, imidization can be performed under conditions of 150 to 500 ° C. and 0.5 to 5 hours. Only one of the adhesive sheet (a) 13 and the adhesive sheet (b) 23 may be imidized.

Moreover, after bonding, the adhesive sheet (a) 13 and the adhesive sheet (b) 23 may be thermoset as necessary. When a silicone resin is used as the adhesive sheet (a) 13 and the adhesive sheet (b) 23, the semiconductor wafer 4 can be satisfactorily fixed to the base 2 by thermosetting. Only one of the adhesive sheet (a) 13 and the adhesive sheet (b) 23 may be thermally cured.

The semiconductor wafer 4 fixed to the other process base 2 can be back-ground. The back grinding can be performed by a conventionally known method.

After the back grinding, the non-circuit forming surface (the back ground surface) of the semiconductor wafer 4 can be processed. Examples of processing methods include electrode formation, metal wiring formation, and protective film formation. Note that a through silicon via may be formed by the processing.

After a desired process such as back grinding or processing is performed on the semiconductor wafer 4, the pedestal 2 is separated from the semiconductor wafer 4.

The method for separating the pedestal 2 from the semiconductor wafer 4 is not particularly limited, and examples thereof include the method exemplified in the description of the method for separating the pedestal 1 from the semiconductor wafer 3.

In the above description, the case where the adhesive strength of the adhesive sheet (b) 23 is lower than that of the adhesive sheet (a) 13 has been described. However, the present invention is not limited to this, and the adhesive strength of the adhesive sheet (b) 23 may be higher than that of the adhesive sheet (a) 13.

In this case, the adhesive force of the adhesive sheet (b) 23 is, for example, a 90 ° peel peel force for a silicon wafer under conditions of a temperature of 23 ± 2 ° C. and a peel speed of 300 mm / min is 0.30 N / 20 mm or more. It is preferable that it is 0.40 N / 20 mm or more. The upper limit of the 90 ° peel peel force is, for example, 30 N / 20 mm or less, preferably 20 N / 20 mm or less.
Moreover, the adhesive strength of the adhesive sheet (a) 13 is, for example, that the 90 ° peel peeling force for a silicon wafer under the conditions of a temperature of 23 ± 2 ° C. and a peeling speed of 300 mm / min is less than 0.30 N / 20 mm. Preferably, it is 0.20 N / 20 mm or less. The lower limit of the 90 ° peel strength is preferably 0.001 N / 20 mm or more, more preferably 0.005 N / 20 mm or more, and further preferably 0.010 N / 20 mm or more.

Moreover, in the above description, the case where the adhesive sheet (a) 13 has the base material 12 and the separator 14 was demonstrated. However, the present invention is not limited to this, and the adhesive sheet (a) 13 may not have the separator 14 and may not have the substrate 12. The adhesive sheet (b) 23 is the same, and the adhesive sheet (b) 23 may not have the separator 24 and may not have the base material 22.

<< Third Present Invention >>
Hereinafter, regarding the third aspect of the present invention, differences from the first aspect of the present invention will be described.

A third object of the present invention is to provide a method for manufacturing a semiconductor device in which a semiconductor wafer can be satisfactorily fixed to a pedestal and the pedestal can be easily separated from the semiconductor wafer.

In the method of manufacturing a semiconductor device according to the third aspect of the present invention, the step (A) of attaching a semiconductor wafer to one surface of the temporary fixing sheet, and attaching a pedestal having a beveled portion to the other surface of the temporary fixing sheet. In step (B), an adhesive layer having higher adhesive force than the temporary fixing sheet is formed between the temporary fixing sheet and the bevel portion of the pedestal, and the temporary fixing sheet is formed on the pedestal. A fixing step (C).

The order of the steps (A) to (C) is not particularly limited. For example, the order of step (A), step (B) and step (C), the order of step (B), step (A) and step (C), step (A), step (C) and step (B) Order, step (B), step (C), step (A), and the like.
Among them, the process (A), the process (B) and the process (C) are easy because the adhesive layer is easy to form and the possibility that the adhesive layer protrudes and the possibility that the adhesive layer is formed more than necessary is low. ) Is preferred.

Hereinafter, a method for manufacturing a semiconductor device according to a third aspect of the present invention will be described with reference to the drawings.
FIG. 17 is a cross-sectional view of the temporary fixing sheet. FIG. 18 is a diagram illustrating a state in which a semiconductor wafer is attached to the temporary fixing sheet. FIG. 19 is a diagram illustrating a state in which an adhesive layer is formed between the temporary fixing sheet and the bevel portion of the pedestal.

Step (A)
In the step (A), the semiconductor wafer 3 is attached to one surface of the temporary fixing sheet 81 (FIG. 18).

A method of attaching the semiconductor wafer 3 to the temporary fixing sheet 81 is not particularly limited, but it is preferable to apply the circuit forming surface of the semiconductor wafer 3 to the temporary fixing sheet 81.

The attaching method is not particularly limited, and examples thereof include a method of attaching at 23 to 250 ° C. and 0.01 to 10 MPa.

After pasting, the temporary fixing sheet 81 is imidized as necessary. Thereby, the temporary fixing sheet 81 and the semiconductor wafer 3 can be favorably bonded. Imidization can be performed by a conventionally known method, for example, imidization can be performed under conditions of 150 to 500 ° C. and 0.5 to 5 hours.

After pasting, the temporary fixing sheet 81 may be thermally cured as necessary. Thereby, the temporary fixing sheet 81 and the semiconductor wafer 3 can be favorably bonded. The heat curing can be performed by a conventionally known method. For example, the heat curing can be performed in a nitrogen atmosphere at 100 to 350 ° C. (preferably 150 to 350 ° C.) for 0.1 to 5 hours.

The thickness of the temporary fixing sheet 81 is not particularly limited, and is, for example, 10 μm or more, preferably 50 μm or more. When the thickness is 10 μm or more, the unevenness on the surface of the semiconductor wafer can be followed, and the temporarily fixing sheet 81 can be filled without a gap. Further, the thickness of the temporary fixing sheet 81 is, for example, 500 μm or less, and preferably 300 μm or less. When the thickness is 500 μm or less, variation in thickness and shrinkage / expansion during heating can be suppressed or prevented.

The shape of the temporary fixing sheet 81 in plan view is not particularly limited, but is usually circular.

The adhesive force of the temporary fixing sheet 81 is lower than the adhesive force of the adhesive layer 80 described later. The adhesive force of the temporary fixing sheet 81 is preferably, for example, a 90 ° peel peeling force to a silicon wafer under a temperature of 23 ± 2 ° C. and a peeling speed of 300 mm / min is less than 0.30 N / 20 mm. More preferably, it is 20 N / 20 mm or less. The adhesive residue of the semiconductor wafer 3 can be prevented as it is less than 0.30 N / 20 mm. On the other hand, the lower limit of the 90 ° peel strength is preferably 0.01 N / 20 mm or more, more preferably 0.02 N / 20 mm or more, and still more preferably 0.05 N / 20 mm or more. When it is 0.01 N / 20 mm or more, the semiconductor wafer 3 can be fixed to the pedestal 1 satisfactorily, and back grinding and the like can be performed satisfactorily.

The adhesive composition constituting the temporary fixing sheet 81 is not particularly limited as long as it is selected so that the adhesive force of the temporary fixing sheet 81 is lower than the adhesive force of the adhesive layer 80 described later. As the adhesive composition constituting the temporary fixing sheet 81, the polyimide resin and the silicone resin described in the first aspect of the present invention can be suitably used. Of these, polyimide resins are preferred from the viewpoints of heat resistance, chemical resistance, and adhesive residue.

As the semiconductor wafer 3, the semiconductor wafer 3 described in the first aspect of the present invention can be preferably used. The semiconductor wafer 3 usually has a bevel portion.

Process (B)
In the step (B), the pedestal 1 having a bevel portion is attached to the other surface of the temporary fixing sheet 81.

The attaching method is not particularly limited, but is preferably attached by roll lamination or a vacuum press. The affixing conditions are not particularly limited, but can be affixed at 23 to 250 ° C. and 0.01 to 10 MPa, for example.

An inclined surface that is inclined from the upper surface and the lower surface of the pedestal 1 toward the side surface (outer side) is formed on the periphery of the pedestal 1. A peripheral portion where such an inclined surface is formed is a bevel portion.

The base 1 is not particularly limited as long as it has a bevel portion. As the pedestal 1, the pedestal 1 described in the first aspect of the present invention can be suitably used. Among these, a silicon wafer or a glass wafer is preferable because of smoothness, availability, and contamination.

Process (C)
In the step (C), an adhesive layer 80 having a higher adhesive force than the temporary fixing sheet 81 is formed between the temporary fixing sheet 81 and the bevel portion of the pedestal 1, and the temporary fixing sheet 81 is placed on the pedestal 1. Fix (FIG. 19).

Specifically, the adhesive layer 80 is formed by applying a liquid adhesive composition between the temporary fixing sheet 81 and the bevel portion of the pedestal 1 and drying the adhesive composition 80. 81 is fixed to the base 1.

The adhesive force of the adhesive layer 80 is preferably, for example, a 90 ° peel peel force for a silicon wafer under the conditions of a temperature of 23 ± 2 ° C. and a peel speed of 300 mm / min is 0.30 N / 20 mm or more. More preferably, it is 40 N / 20 mm or more. When it is 0.30 N / 20 mm or more, the temporarily fixing sheet 81 can be fixed to the pedestal 1 satisfactorily, and back grinding can be performed well. The upper limit of the 90 ° peel peel force is not particularly limited and is preferably as large as possible. For example, it is 30 N / 20 mm or less, preferably 20 N / 20 mm or less.

The material constituting the adhesive layer 80 is not particularly limited as long as it is selected so that the adhesive force of the adhesive layer 80 is higher than the adhesive force of the temporary fixing sheet 81. As a material constituting the adhesive layer 80, the aforementioned polyimide resin and the aforementioned silicone resin can be suitably used. Especially, the said polyimide resin is preferable from the point of heat resistance, chemical resistance, and adhesive residue.

FIG. 20A is a diagram illustrating a state in which an adhesive layer 80 is formed between the temporary fixing sheet 81 and the bevel portion of the pedestal 1. FIG. 20B is an enlarged view around the bevel portion.
As shown in FIG. 20B, it is preferable that the end portion of the temporary fixing sheet 81 is inside the end portion of the pedestal 1 and outside the tilt start position of the bevel portion of the pedestal 1. Specifically, the distance in the lateral direction (horizontal to the surface of the pedestal 1) between the end of the pedestal 1 and the end of the temporary fixing sheet 81 is D1, and the end of the pedestal 1 and the bevel portion of the pedestal 1 If the lateral distance from the tilt start position is D2, D1 is preferably one-tenth of D2, that is, larger than (D2) / 10. When D1 is larger than 1/10 of D2, it is possible to prevent the temporarily fixing sheet 81 from touching another member (for example, a cassette used for conveyance) and turning up.
On the other hand, D1 is preferably smaller than two-thirds of D2, that is, (D2) × (2/3). When D1 is smaller than two-thirds of D2, the area of the bonded portion by the adhesive layer 80 can be secured to some extent, and the bonding reliability is excellent.
Note that D2 is usually 0.1 to 0.4 mm.

(A) of FIG. 21 is a figure which shows a mode that the adhesive bond layer was formed between the sheet | seat for temporary fixing, and the bevel part of a base. FIG. 21B is an enlarged view around the bevel portion of the semiconductor wafer.
As shown in FIG. 21B, the end portion of the temporary fixing sheet 81 is preferably inside the end portion of the semiconductor wafer 3 and outside the tilt start position of the bevel portion of the semiconductor wafer 3. .
Specifically, the distance in the horizontal direction (horizontal direction of the surface of the semiconductor wafer 3) between the end of the semiconductor wafer 3 and the end of the temporary fixing sheet 81 is D3, and the end of the semiconductor wafer 3 and the semiconductor wafer 3 When the distance in the horizontal direction from the inclination start position of the bevel portion is D4, D3 is preferably one-tenth of D4, that is, larger than (D4) / 10. When D3 is larger than 1/10 of D4, it is possible to prevent the temporarily fixing sheet 81 from touching another member (for example, a cassette used for conveyance) and turning up.
On the other hand, D3 is preferably smaller than two-thirds of D4, that is, (D4) × (2/3). When D3 is smaller than two-thirds of D4, the area of the bonded portion by the adhesive layer 80 can be secured to some extent, and the bonding reliability is excellent.
D4 is usually 0.1 to 0.4 mm.

It is preferable to perform back grinding on the semiconductor wafer 3 fixed to the pedestal 1 by other process steps (A) to (C). The back grinding can be performed by a conventionally known method.

It is preferable to separate the pedestal 1 from the temporary fixing sheet 81 after the semiconductor wafer 3 is subjected to desired processing such as back grinding and processing.

The method for separating the pedestal 1 from the temporary fixing sheet 81 is not particularly limited.
For example, a method of cutting and separating the temporary fixing sheet 80 and a method of separating by reducing the adhesive force of the adhesive layer 80 are suitable. Among these, a method of cutting and temporarily separating the temporary fixing sheet 81 is preferable because a load is not applied to the semiconductor wafer 3.

FIG. 22 is a diagram illustrating a state in which the temporary fixing sheet 81 has been cut. As shown in FIG. 22, it is preferable to make a cut 99 in the temporary fixing sheet 81 until it reaches the pedestal 1, and it is more preferable to make a cut 99 in the temporary fixing sheet 81 until it reaches the bevel portion of the pedestal 1. The cutting method is not particularly limited, and can be cut by a conventionally known method such as a cutter or a laser.

The method for reducing the adhesive strength of the adhesive layer 80 is not particularly limited. The adhesive layer 80 is dissolved with a solvent, the adhesive layer 80 is formed of a material whose adhesive strength is reduced by heating, and the adhesive layer 80 is bonded by heating. A method for reducing the force is mentioned.

In the above description, the semiconductor wafer 3 having a circuit forming surface and a non-circuit forming surface is used. However, it is not limited to those having a circuit formation surface and a non-circuit formation surface, and both surfaces may be those having a non-circuit formation surface.

Further, the case where the semiconductor wafer 3 fixed to the pedestal 1 by the steps (A) to (C) is processed after back grinding has been described. However, the semiconductor wafer 3 may be processed without back grinding.

Moreover, the case where the cross section was a rectangle was demonstrated as a shape of the sheet | seat for temporary fixing. However, the shape of the temporary fixing sheet is not particularly limited. For example, as shown in FIG. 23, the temporary fixing sheet may be provided with a recess in the peripheral edge.

As described above, in the third production method of the present invention, the order of the steps (A) to (C) is not particularly limited. For example, the step (C) can be performed before the step (B). In this case, an adhesive layer as a sheet-like material is provided in advance on the peripheral edge portion (portion corresponding to the bevel portion) of the temporary fixing sheet, so that the adhesive layer adheres to the bevel portion. A pedestal can be attached.

<< Fourth Invention >>
Hereinafter, regarding the fourth invention (4-1 invention, 4-2 invention, 4-3 invention, 4-4 invention and 4-5 invention), Differences from the first invention will be described.

A fourth aspect of the present invention is to provide a method for manufacturing a semiconductor device that can satisfactorily fix a semiconductor wafer to a pedestal and can easily separate the pedestal from the semiconductor wafer.

[4-1 Present Invention]
The 4-1 semiconductor device manufacturing method of the present invention includes a first adhesive layer and a second layer having an adhesive strength lower than that of the first adhesive layer, and a peripheral portion of an adhesive sheet is the first adhesive layer. A step of preparing an adhesive sheet that is formed by one adhesive layer, and a central portion inside the peripheral portion is formed by stacking the first adhesive layer and the second layer; and And fixing the semiconductor wafer to the pedestal, and cutting the first adhesive layer until reaching the second layer to separate the pedestal from the semiconductor wafer.

First, it has a first adhesive layer and a second layer whose adhesive strength is lower than that of the first adhesive layer, and a peripheral portion of the adhesive sheet is formed by the first adhesive layer, and is more than the peripheral portion. An adhesive sheet is prepared in which an inner central portion is formed by stacking the first adhesive layer and the second layer.

FIG. 24 is a schematic cross-sectional view of the adhesive sheet 5 that can be used in the fourth embodiment of the present invention. As shown in FIG. 24, the adhesive sheet 5 has a peripheral portion 54 formed by the first adhesive layer 50, and a central portion 53 inside the peripheral portion 54 has the first adhesive layer 50 and the second adhesive layer 50. It is formed by stacking with the layer 51. That is, the adhesive sheet 5 includes a second layer 51 and a first adhesive layer 50 that is laminated on the second layer 51 in such a manner as to cover the upper surface and side surfaces of the second layer 51. The adhesive force of the second layer 51 is lower than the adhesive force of the first adhesive layer 50.

A peripheral portion 54 of the adhesive sheet 5 is formed by the first adhesive layer 50. Since the first adhesive layer 50 having higher adhesive strength than the second layer 51 is present in the peripheral portion 54, the semiconductor wafer can be firmly fixed to the pedestal in this portion.
A central portion 53 inside the peripheral portion 54 is formed by stacking the first adhesive layer 50 and the second layer 51. The semiconductor wafer or the pedestal can be firmly fixed on the surface where only the first adhesive layer 50 is exposed. Further, when the second layer 51 is in contact with the pedestal, the adhesive sheet is easily peeled off from the pedestal, the adhesive residue is small, and the pedestal is easy to reuse.

FIG. 25 is a plan view of the adhesive sheet 5 that can be used in the fourth embodiment of the present invention.
As shown in FIG. 25, the adhesive sheet 5 has a circular shape when viewed in plan. As the adhesive sheet 5, the adhesive sheet 5 described in the first aspect of the present invention can be suitably used.

As shown in FIG. 26, the adhesive sheet 5 may have other layers formed thereon. FIG. 26 is a schematic cross-sectional view of the adhesive sheet 5 that can be used in (4-1) the present invention. In the adhesive sheet 5 of FIG. 26, a third layer 55 is formed across the peripheral portion 54 and the central portion 53. The adhesive sheet 5 with the third layer 55 can be easily peeled from the semiconductor wafer by sticking the surface on which the third layer 55 having a lower adhesive strength than the first adhesive layer 50 is exposed to the semiconductor wafer. . Further, the adhesive residue on the semiconductor wafer can be eliminated, and the semiconductor wafer cleaning step can be omitted.

In the following description, the case where the adhesive sheet 5 shown in FIGS. 24 and 25 is used will be described.

After preparing the adhesive sheet 5, the semiconductor wafer 41 is fixed to the pedestal 31 using the adhesive sheet 5. FIG. 27 is a schematic diagram showing a state in which the semiconductor wafer 41 is fixed to the pedestal 31.

The method for fixing the semiconductor wafer 41 to the pedestal 31 using the adhesive sheet 5 is not particularly limited, but the surface of the adhesive sheet 5 on which the first adhesive layer 50 and the second layer 51 are exposed is attached to the pedestal 31. A method of adhering the surface of the adhesive sheet 5 on which only the first adhesive layer 50 is exposed to the circuit forming surface of the semiconductor wafer 41 is suitable (FIG. 27).

As the semiconductor wafer 41, the semiconductor wafer 3 described in the first aspect of the present invention can be suitably used. As the pedestal 31, the pedestal 1 described in the first aspect of the present invention can be suitably used.

The method of attaching (fixing) is not particularly limited, but pressure bonding is preferable. The crimping is usually performed while pressing with a pressing means such as a crimping roll. As the pressure bonding conditions, for example, 20 to 300 ° C., 0.001 to 10 MPa, and 0.001 to 10 mm / sec are preferable. The crimping time is usually 0.1 to 10 minutes.
After the pressure bonding, the first adhesive layer 50 and the second layer 51 are imidized as necessary. Thereby, the semiconductor wafer 41 can be satisfactorily fixed to the pedestal 31. Imidization can be performed by a conventionally known method, for example, imidization can be performed under conditions of 150 to 500 ° C. and 0.5 to 5 hours. Only one of the first adhesive layer 50 and the second layer 51 may be imidized.

Next, it is preferable to back grind the semiconductor wafer 41. The back grinding can be performed by a conventionally known method.

After the back grinding, the non-circuit forming surface (back ground surface) of the semiconductor wafer 41 can be processed. Examples of processing methods include electrode formation, metal wiring formation, and protective film formation. Note that a through silicon via may be formed by the processing.

After performing desired processing such as back grinding and processing, the first adhesive layer 50 is cut and the pedestal 31 is separated from the semiconductor wafer 41. FIG. 28 is a schematic diagram illustrating a state in which the first adhesive layer 50 is cut.
The cutting method is not particularly limited, and it can be cut by a conventionally known method such as a cutter or a laser.

In the separation step, the first adhesive layer 50 is cut. Thereby, the continuity of the 1st adhesive bond layer 50 can be destroyed, and the base 31 can be easily isolate | separated from the semiconductor wafer 41 by applying external force as needed. Moreover, since the 1st adhesive bond layer 50 is formed in the peripheral part 54 of the adhesive sheet 5, it is easy to put the cutting | disconnection 101 in the 1st adhesive bond layer 50. FIG.

In the above description, the case where the adhesive sheet 5 having a circular shape in plan view is used has been described. However, the shape is not particularly limited, and may be another shape such as a polygon or an ellipse.

Moreover, the case where the adhesive sheet 5 whose shape of the 2nd layer 51 is circular when planarly viewed was used was demonstrated. However, the shape is not particularly limited, and may be another shape such as a polygon or an ellipse.

In the above description, as a method of fixing the semiconductor wafer 41 to the pedestal 31 using the adhesive sheet 5, the surfaces of the adhesive sheet 5 on which the first adhesive layer 50 and the second layer 51 are exposed are pasted on the pedestal 31. The method of attaching the surface of the adhesive sheet 5 where only the first adhesive layer 50 is exposed to the circuit forming surface of the semiconductor wafer 41 has been described. However, the method for fixing the semiconductor wafer 41 to the pedestal 31 using the adhesive sheet 5 is not particularly limited, and the surface of the adhesive sheet 5 on which only the first adhesive layer 50 is exposed is attached to the pedestal 31, and the adhesive sheet 5 may be a method in which the surface on which the first adhesive layer 50 and the second layer 51 are exposed is attached to the circuit forming surface of the semiconductor wafer 41.

Moreover, the case where what has a circuit formation surface and a non-circuit formation surface was used as the semiconductor wafer 41 was demonstrated. However, it is not limited to those having a circuit formation surface and a non-circuit formation surface, and both surfaces may be those having a non-circuit formation surface.

[4-2th Invention]
The manufacturing method of a semiconductor device according to the 4-2 of the present invention includes a first adhesive layer and a second layer having an adhesive strength lower than that of the first adhesive layer, and a peripheral portion of an adhesive sheet is the first adhesive layer. A step of preparing an adhesive sheet formed by one adhesive layer and having a central portion inside the peripheral portion formed by the second layer; and fixing the semiconductor wafer to the pedestal using the adhesive sheet And cutting the first adhesive layer until the second layer is reached, separating the pedestal from the semiconductor wafer.

First, it has a first adhesive layer and a second layer whose adhesive strength is lower than that of the first adhesive layer, and a peripheral portion of the adhesive sheet is formed by the first adhesive layer, and is more than the peripheral portion. An adhesive sheet having an inner central portion formed by the second layer is prepared.

FIG. 29 is a schematic cross-sectional view of the adhesive sheet 6 that can be used in the 4-2th aspect of the present invention. As shown in FIG. 29, in the adhesive sheet 6, the peripheral portion 64 is formed by the first adhesive layer 60, and the central portion 63 inside the peripheral portion 64 is formed by the second layer 61. . The adhesive force of the second layer 61 is lower than the adhesive force of the first adhesive layer 60.

The peripheral portion 64 of the adhesive sheet 6 is formed by the first adhesive layer 60. Since the first adhesive layer 60 having a higher adhesive force than the second layer 61 is present in the peripheral portion 64, the semiconductor wafer can be firmly fixed to the pedestal in this portion.
A central portion 63 inside the peripheral portion 64 is formed by the second layer 61. Since the second layer 61 is in contact with the pedestal, the adhesive sheet 6 is easily peeled off from the pedestal, the adhesive residue is small, and the pedestal is easy to reuse.

FIG. 30 is a plan view of the adhesive sheet 6 that can be used in the 4-2th aspect of the present invention. As shown in FIG. 30, the adhesive sheet 6 has a circular shape when viewed in plan. As the adhesive sheet 6, the adhesive sheet 6 described in the first aspect of the present invention can be suitably used.

As shown in FIG. 31, the adhesive sheet may be formed with other layers. FIG. 31 is a schematic sectional view of an adhesive sheet 6 that can be used in the 4-2th aspect of the present invention. In the adhesive sheet 6 of FIG. 31, a third layer 65 is formed across the peripheral portion 64 and the central portion 63. The adhesive sheet 6 with the third layer 65 can be easily peeled from the semiconductor wafer by attaching the surface on which the third layer 65 having a lower adhesive strength than the first adhesive layer 60 is exposed to the semiconductor wafer. . Further, the adhesive residue on the semiconductor wafer can be eliminated, and the semiconductor wafer cleaning step can be omitted.

In the following description, the case where the adhesive sheet 6 shown in FIGS. 29 and 30 is used will be described.

After preparing the adhesive sheet 6, the semiconductor wafer 42 is fixed to the base 32 using the adhesive sheet 6.

The fixing method is not particularly limited, but pressure bonding is preferable. The crimping is usually performed while pressing with a pressing means such as a crimping roll. As the pressure bonding conditions, for example, 20 to 300 ° C., 0.001 to 10 MPa, and 0.001 to 10 mm / sec are preferable. The crimping time is usually 0.1 to 10 minutes.
After the pressure bonding, the first adhesive layer 60 and the second layer 61 are imidized as necessary. Thereby, the semiconductor wafer 42 can be satisfactorily fixed to the pedestal 32. Imidization can be performed by a conventionally known method, for example, imidization can be performed under conditions of 150 to 500 ° C. and 0.5 to 5 hours. Only one of the first adhesive layer 60 and the second layer 61 may be imidized.

The semiconductor wafer 42 is the same as the semiconductor wafer 41. The pedestal 32 is the same as the pedestal 31.

Next, the semiconductor wafer 42 is preferably back-ground. The back grinding can be performed by a conventionally known method.

After the back grinding, the non-circuit forming surface (back ground surface) of the semiconductor wafer 42 can be processed. Examples of processing methods include electrode formation, metal wiring formation, and protective film formation. Note that a through silicon via may be formed by the processing.

After performing desired processing such as back grinding and processing, the first adhesive layer 60 is cut, and the pedestal 32 is separated from the semiconductor wafer 42. FIG. 32 is a schematic diagram illustrating a state in which the first adhesive layer is cut.
The cutting method is not particularly limited, and it can be cut by a conventionally known method such as a cutter or a laser.

In the separation step, the first adhesive layer 60 is cut. Thereby, the continuity of the 1st adhesive bond layer 60 can be destroyed, and the base 32 can be easily isolate | separated from the semiconductor wafer 42 by applying external force as needed. Further, since the first adhesive layer 60 is formed on the peripheral portion 64 of the adhesive sheet 6, it is easy to make a cut 102 in the first adhesive layer 60.

In the above description, the adhesive sheet 6 having a circular shape when viewed in plan has been described. However, the shape is not particularly limited, and may be another shape such as a polygon or an ellipse.

Further, the adhesive sheet 6 in which the shape of the second layer 61 is circular when viewed in plan has been described. However, the shape is not particularly limited, and may be another shape such as a polygon or an ellipse.

[4-3 Present Invention]
A method for manufacturing a semiconductor device according to a fourth aspect of the present invention includes a step of preparing an adhesive sheet in which a first adhesive layer and a second layer having an adhesive strength lower than that of the first adhesive layer are laminated. A step of fixing the semiconductor wafer to a pedestal using the adhesive sheet, and a cut is made at a boundary between the first adhesive layer and the second layer, and the first adhesive layer and the second layer Separating.

First, an adhesive sheet is prepared in which a first adhesive layer and a second layer whose adhesive strength is lower than that of the first adhesive layer are laminated.

FIG. 33 is a schematic cross-sectional view of an adhesive sheet 7 that can be used in the fourth to third aspects of the present invention. As shown in FIG. 33, the adhesive sheet 7 is formed by laminating a first adhesive layer 70 and a second layer 71. The adhesive force of the second layer 71 is lower than the adhesive force of the first adhesive layer 70.

As the adhesive sheet 7, the adhesive sheet 7 described in the second aspect of the present invention can be suitably used.

As shown in FIG. 34, the adhesive sheet may be formed with other layers. FIG. 34 is a schematic cross-sectional view of an adhesive sheet that can be used in the fourth to fourth present inventions. The adhesive sheet 7 of FIG. 34 is formed by laminating a third layer 75, a second layer 71, and a first adhesive layer 70.

In the following description, the case where the adhesive sheet 7 shown in FIG. 33 is used will be described.

FIG. 35 is a schematic diagram illustrating a state in which the semiconductor wafer 43 is attached to the adhesive sheet 7. FIG. 36 is a schematic diagram showing a state in which the semiconductor wafer 43 is fixed to the pedestal 33.

The semiconductor wafer 43 is fixed to the pedestal 33 using the adhesive sheet 7. For example, the semiconductor wafer 43 is bonded to the first adhesive layer 70, and the pedestal 33 is bonded to the second layer 71, thereby fixing the semiconductor wafer 43 to the pedestal 33. In the case of this method, the first adhesive layer 70 can follow the irregularities on the surface of the semiconductor wafer 43, and the semiconductor wafer 43 can be fixed to the pedestal 33 well. On the other hand, since the second layer 71 having an adhesive force lower than that of the first adhesive layer 70 is in contact with the pedestal 33, the adhesive sheet 7 is easily peeled from the pedestal 33. Moreover, there is little adhesive residue of the base 33, and the base 33 is easy to reuse.

First, the circuit formation surface of the semiconductor wafer 43 and the first adhesive layer 70 are bonded together (FIG. 35).

The bonding method (sticking method) is not particularly limited, and examples thereof include a method of bonding at 23 to 250 ° C. and 0.01 to 10 MPa.
When the area of the adhesive sheet 7 is larger than the area of the semiconductor wafer 43, the adhesive sheet 7 may be cut before or after bonding as necessary.

The semiconductor wafer 43 is the same as the semiconductor wafer 41.

Next, the base 33 and the second layer 71 are bonded together (FIG. 36).

The bonding method (sticking method) is not particularly limited, and examples thereof include a method of bonding at 23 to 250 ° C. and 0.01 to 10 MPa.
In addition, what is necessary is just to cut the adhesive sheet 7 as needed, when the area of the adhesive sheet 7 is larger than the area of the base 33. FIG.

The pedestal 33 is the same as the pedestal 31.

After bonding, the first adhesive layer 70 and the second layer 71 are imidized as necessary. Thereby, the semiconductor wafer 43 can be satisfactorily fixed to the pedestal 33. Imidization can be performed by a conventionally known method, for example, imidization can be performed under conditions of 150 to 500 ° C. and 0.5 to 5 hours. Only one of the first adhesive layer 70 and the second layer 71 may be imidized.

In addition, after bonding, the first adhesive layer 70 and the second layer 71 may be thermoset as necessary. When a silicone resin is used as the first adhesive layer 70 and the second layer 71, the semiconductor wafer 43 can be satisfactorily fixed to the pedestal 33 by thermosetting. Only one of the first adhesive layer 70 and the second layer 71 may be thermally cured.

Next, it is preferable to back grind the semiconductor wafer 43 fixed to the pedestal 33. The back grinding can be performed by a conventionally known method.

After the back grinding, the non-circuit forming surface (back ground surface) of the semiconductor wafer 43 can be processed. Examples of processing methods include electrode formation, metal wiring formation, and protective film formation. Note that a through silicon via may be formed by the processing.

After a desired process such as back grinding or processing is performed on the semiconductor wafer 43, a cut is made at the boundary between the first adhesive layer 70 and the second layer 71, and the first adhesive layer 70 and the second layer are formed. 71 is separated. FIG. 37 is a schematic diagram showing a state in which a cut 103 is made at the boundary between the first adhesive layer 70 and the second layer 71.
The cutting method is not particularly limited, and can be cut by a conventionally known method such as a cutter or a laser. The cutting depth is not particularly limited, but is usually 0.1 to 10 mm.

Since the adhesive force of the second layer 71 is lower than that of the first adhesive layer 70, the first adhesive layer 70 and the second layer 71 can be easily separated from the notch 103 by applying an external force as necessary. it can.

In the above description, the method of attaching the semiconductor wafer 43 to the first adhesive layer 70 and attaching the pedestal 33 to the second layer 71 has been described. However, the present invention is not limited to this, and the base 33 may be attached to the first adhesive layer 70 and the semiconductor wafer 43 may be attached to the second layer 71.

[4-4 Present Invention]
According to a fourth method of manufacturing a semiconductor device of the present invention, a step (A) of attaching a semiconductor wafer to the adhesive sheet (a), a step (B) of attaching a base to the adhesive sheet (b), and the above steps Bonding the adhesive sheet (a) of the semiconductor wafer with the adhesive sheet (a) obtained by (A) and the adhesive sheet (b) of the base with the adhesive sheet (b) obtained by the step (B) , A step (C) of obtaining a laminate in which the pedestal, the adhesive sheet (b), the adhesive sheet (a), and the semiconductor wafer are sequentially laminated, and the adhesive sheet (a) and the adhesive sheet in the laminate A step (D) of cutting the boundary with (b) to separate the adhesive sheet (a) and the adhesive sheet (b). Moreover, one adhesive force of the said adhesive sheet (a) and (b) is lower than the other.

The semiconductor wafer can be satisfactorily fixed to the pedestal because the adhesive sheet having a relatively high adhesive force is used in combination instead of using only the adhesive sheet having a low adhesive force.

FIG. 38 is a schematic cross-sectional view of an adhesive sheet (a) that can be used in the fourth to fourth present inventions. FIG. 39 is a schematic diagram showing a state in which a semiconductor wafer is attached to the adhesive sheet (a). FIG. 40 is a schematic cross-sectional view of an adhesive sheet adhesive sheet (b) that can be used in the fourth to fourth present invention. FIG. 41 is a schematic diagram showing a state in which a pedestal is attached to the adhesive sheet (b). FIG. 42 is a schematic diagram showing a state in which the semiconductor wafer is fixed to the pedestal using the adhesive sheets (a) and (b).

Step (A)
In the step (A), the semiconductor wafer 44 is attached to the adhesive sheet (a) 13 (FIG. 39).

First, the adhesive sheet (a) 13 will be described. As shown in FIG. 38, the adhesive sheet (a) 13 has a substrate 12 on one side and a separator 14 on the other side. As the adhesive sheet (a) 13, the adhesive sheet (a) 13 described in the second aspect of the present invention can be suitably used.

The semiconductor wafer 44 is the same as the semiconductor wafer 41.

In step A, the separator 14 is peeled off, and the semiconductor wafer 44 is attached to the adhesive sheet (a) 13.

The attaching method is not particularly limited, and examples thereof include a method of attaching at 23 to 250 ° C. and 0.01 to 10 MPa.
In addition, when the area of the adhesive sheet (a) 13 is larger than the area of the semiconductor wafer 44, the adhesive sheet (a) 13 may be cut before or after attachment as necessary.

Process (B)
In the step (B), a pedestal 34 is attached to the adhesive sheet (b) 23 (FIG. 41).

As shown in FIG. 40, the adhesive sheet (b) 23 has a base material 22 on one surface and a separator 24 on the other surface. As the adhesive sheet (b) 23, the adhesive sheet (b) 23 described in the second aspect of the present invention can be suitably used.

The pedestal 34 is the same as the pedestal 31.

In step B, the separator 24 is peeled off, and a pedestal 34 is attached to the adhesive sheet (b) 23.

The attaching method is not particularly limited, and examples thereof include a method of attaching at 23 to 250 ° C. and 0.01 to 10 MPa.
In addition, when the area of the adhesive sheet (b) 23 is larger than the area of the pedestal 34, the adhesive sheet (b) 23 may be cut before or after attachment as necessary.

Process (C)
In the step (C), the adhesive sheet (a) 13 of the semiconductor wafer 44 with the adhesive sheet (a) 13 obtained in the step (A) and the pedestal 34 with the adhesive sheet (b) 23 obtained in the step (B). The adhesive sheet (b) 23 is bonded. Thereby, the laminated body in which the base 34, the adhesive sheet (b) 23, the adhesive sheet (a) 13, and the semiconductor wafer 44 are sequentially laminated is obtained (FIG. 42).

The bonding method is not particularly limited. After bonding, the adhesive sheet (a) 13 and the adhesive sheet (b) 23 are imidized as necessary. Thereby, the semiconductor wafer 44 can be satisfactorily fixed to the pedestal 34. Imidization can be performed by a conventionally known method,
For example, imidization can be performed under conditions of 150 to 500 ° C. and 0.5 to 5 hours. Only one of the adhesive sheet (a) 13 and the adhesive sheet (b) 23 may be imidized.

Moreover, after bonding, the adhesive sheet (a) 13 and the adhesive sheet (b) 23 may be thermoset as necessary. When a silicone resin is used as the adhesive sheet (a) 13 and the adhesive sheet (b) 23, the semiconductor wafer 44 can be satisfactorily fixed to the pedestal 34 by thermosetting. Only one of the adhesive sheet (a) 13 and the adhesive sheet (b) 23 may be thermally cured.

The semiconductor wafer 44 fixed to the pedestal 34 in the step (C) can be back-ground. The back grinding can be performed by a conventionally known method.

After back grinding, the non-circuit forming surface (back ground surface) of the semiconductor wafer 44 can be processed. Examples of processing methods include electrode formation, metal wiring formation, and protective film formation. Note that a through silicon via may be formed by the processing.

Process (D)
After performing desired processing such as back grinding and processing on the semiconductor wafer 44, a cut is made at the boundary between the adhesive sheet (a) 13 and the adhesive sheet (b) 23, and the adhesive sheet (a) 13 and the adhesive sheet ( b) Separate 23. FIG. 43 is a schematic diagram showing a state in which a cut 104 is made at the boundary between the adhesive sheet (a) 13 and the adhesive sheet (b) 23.
The cutting method is not particularly limited, and can be cut by a conventionally known method such as a cutter or a laser. The cutting depth is not particularly limited, but is usually 0.1 to 10 mm.

Since the adhesive force of the adhesive sheet (b) 23 is lower than that of the adhesive sheet (a) 13, the adhesive sheet (a) 13 and the adhesive sheet (b) 23 can be easily started from the notch 104 by applying an external force as necessary. Can be separated.

In this case, the values described in the second aspect of the present invention can be adopted as the adhesive force of the adhesive sheet (b) 23 and the adhesive force of the adhesive sheet (a) 13.

[4-5 Present Invention]
According to a fourth aspect of the present invention, there is provided a semiconductor device manufacturing method comprising: a step (I) of attaching a semiconductor wafer to one surface of a temporary fixing sheet; and a pedestal having a bevel portion on the other surface of the temporary fixing sheet. A temporary fixing adhesive layer having a higher adhesive force than the temporary fixing sheet between the temporary fixing sheet and the bevel portion of the pedestal, and the temporary fixing A step (III) of fixing the sheet to the pedestal, and a step of cutting the temporary fixing sheet after the steps (I) to (III) to separate the pedestal from the temporary fixing sheet (IV ).

The order of the steps (I) to (III) is not particularly limited. For example, the order of step (I), step (II) and step (III), the order of step (II), step (I) and step (III), step (I), step (III) and step (II) And the order of step (II), step (III) and step (I). Among them, the temporary fixing adhesive layer is easy to form, and the possibility of the temporary fixing adhesive layer sticking out and the possibility of forming the temporary fixing adhesive layer more than the necessary amount are low. The order of step (II) and step (III) is preferred.

FIG. 44 is a cross-sectional view of the temporary fixing sheet. FIG. 45 is a diagram illustrating a state in which a semiconductor wafer is attached to the temporary fixing sheet. FIG. 46 is a diagram illustrating a state in which an adhesive layer for temporary fixing is formed between the temporary fixing sheet and the bevel portion of the pedestal.

Step (I)
In step (I), the semiconductor wafer 45 is attached to one surface of the temporary fixing sheet 81 (FIG. 45).

The method for attaching the semiconductor wafer 45 to the temporary fixing sheet 81 is not particularly limited, but it is preferable to apply the circuit forming surface of the semiconductor wafer 45 to the temporary fixing sheet 81.

After pasting, the temporary fixing sheet 81 is imidized as necessary. Thereby, the temporary fixing sheet 81 and the semiconductor wafer 45 can be favorably bonded. Imidization can be performed by a conventionally known method, for example, imidization can be performed under conditions of 150 to 500 ° C. and 0.5 to 5 hours.

After pasting, the temporary fixing sheet 81 may be thermally cured as necessary. Thereby, the temporary fixing sheet 81 and the semiconductor wafer 45 can be favorably bonded. The heat curing can be performed by a conventionally known method. For example, the heat curing can be performed in a nitrogen atmosphere at 100 to 350 ° C. (preferably 150 to 350 ° C.) for 0.1 to 5 hours.

As the temporary fixing sheet 81, the temporary fixing sheet 81 described in the third aspect of the present invention can be suitably used.

The semiconductor wafer 45 is the same as the semiconductor wafer 41.

Step (II)
In step (II), a pedestal 35 having a bevel portion is attached to the other surface of the temporary fixing sheet 81.

An inclined surface that is inclined from the upper surface and the lower surface of the pedestal 35 toward the side surface (outer side) is formed on the periphery of the pedestal 35. A peripheral portion where such an inclined surface is formed is a bevel portion.

The pedestal 35 is not particularly limited as long as it has a bevel portion, and the pedestal 1 described in the third aspect of the present invention can be suitably used.

Step (III)
In the step (III), a temporary fixing adhesive layer 80 having higher adhesive force than the temporary fixing sheet 81 is formed between the temporary fixing sheet 81 and the bevel portion of the pedestal 35, and the temporary fixing sheet 81 is It fixes to the base 35 (FIG. 46).

Specifically, a temporary adhesive layer 80 is formed by applying a liquid adhesive composition between the temporary fixing sheet 81 and the bevel portion of the pedestal 35 and drying it. The stopping sheet 81 is fixed to the base 35.

As the temporary fixing adhesive layer 80, the adhesive layer 80 described in the third aspect of the present invention can be preferably used.

FIG. 47A is a diagram illustrating a state in which the temporary fixing adhesive layer 80 is formed between the temporary fixing sheet 81 and the bevel portion of the pedestal 35. FIG. 47B is an enlarged view around the bevel portion.
As shown in FIG. 47 (b), the end portion of the temporary fixing sheet 81 is preferably inside the end portion of the pedestal 35 and outside the tilt start position of the bevel portion of the pedestal 35. Specifically, the distance in the horizontal direction (horizontal to the surface of the pedestal 35) between the end of the pedestal 35 and the end of the temporary fixing sheet 81 is D1, and the end of the pedestal 35 and the bevel portion of the pedestal 35 are If the lateral distance from the tilt start position is D2, D1 is preferably one-tenth of D2, that is, larger than (D2) / 10. When D1 is larger than 1/10 of D2, it is possible to prevent the temporarily fixing sheet 81 from touching another member (for example, a cassette used for conveyance) and turning up.
On the other hand, D1 is preferably smaller than two-thirds of D2, that is, (D2) × (2/3). When D1 is smaller than two-thirds of D2, the area of the bonded portion by the adhesive layer 80 can be secured to some extent, and the bonding reliability is excellent.
Note that D2 is usually 0.1 to 0.4 mm.

FIG. 48A is a diagram illustrating a state in which a temporary fixing adhesive layer is formed between the temporary fixing sheet and the bevel portion of the pedestal. FIG. 48B is an enlarged view around the bevel portion of the semiconductor wafer. As shown in FIG. 48 (b), the end portion of the temporary fixing sheet 81 is preferably inside the end portion of the semiconductor wafer 45 and outside the tilt start position of the bevel portion of the semiconductor wafer 45. .
Specifically, the distance in the lateral direction (horizontal direction of the surface of the semiconductor wafer 45) between the end portion of the semiconductor wafer 45 and the end portion of the temporary fixing sheet 81 is D3, and the end portion of the semiconductor wafer 45 and the semiconductor wafer 45 are aligned. When the distance in the horizontal direction from the inclination start position of the bevel portion is D4, D3 is preferably one-tenth of D4, that is, larger than (D4) / 10. When D3 is larger than 1/10 of D4, it is possible to prevent the temporarily fixing sheet 81 from touching another member (for example, a cassette used for conveyance) and turning up.
On the other hand, D3 is preferably smaller than two-thirds of D4, that is, (D4) × (2/3). When D3 is smaller than two-thirds of D4, the area of the bonded portion by the adhesive layer 80 can be secured to some extent, and the bonding reliability is excellent.
D4 is usually 0.1 to 0.4 mm.

It is preferable to perform back grinding on the semiconductor wafer 45 fixed to the pedestal 35 by the other process steps (I) to (III). The back grinding can be performed by a conventionally known method.

After the back grinding, the non-circuit forming surface (the back ground surface) of the semiconductor wafer 45 can be processed. Examples of processing methods include electrode formation, metal wiring formation, and protective film formation. Note that a through silicon via may be formed by the processing.

Step (IV)
After performing desired processing such as back grinding and processing on the semiconductor wafer 45, the temporary fixing sheet 81 is cut to separate the pedestal 35 from the temporary fixing sheet 81.

FIG. 49 is a diagram illustrating a state in which a cut 105 has been made in the temporary fixing sheet 81. As shown in FIG. 49, it is preferable to make a cut 105 in the temporary fixing sheet 81 until it reaches the pedestal 35, and it is more preferable to make a cut 105 in the temporary fixing sheet 81 until it reaches the bevel portion of the pedestal 35. The cutting method is not particularly limited, and can be cut by a conventionally known method such as a cutter or a laser.

In the above description, the case where the cross section is rectangular has been described as the shape of the temporary fixing sheet. However, the shape of the temporary fixing sheet is not particularly limited. For example, as shown in FIG. 50, the temporary fixing sheet may be provided with a concave portion at the peripheral edge.

As described above, the order of steps (I) to (III) is not particularly limited. For example, step (III) can be performed before step (II). In this case, a temporary fixing adhesive layer as a sheet-like material is provided in advance on the peripheral edge portion of the temporary fixing sheet (the portion corresponding to the bevel portion) so that the temporary fixing adhesive layer adheres to the bevel portion. A pedestal may be attached to the temporary fixing sheet.

<< Fifth Invention >>
Hereinafter, regarding the fifth aspect of the present invention, differences from the first aspect of the present invention will be described.

A fifth object of the present invention is to provide an adhesive sheet for manufacturing a semiconductor device that can satisfactorily fix a semiconductor wafer to a pedestal and can easily separate the pedestal from the semiconductor wafer. Moreover, it aims at providing the manufacturing method of the semiconductor device using this adhesive sheet for semiconductor device manufacture.

[Adhesive sheet]
The adhesive sheet for manufacturing a semiconductor device according to a fifth aspect of the present invention includes a first adhesive layer and a second layer having a structure having a large number of through holes and / or a non-woven fabric structure as a skeleton, The adhesive force of the second layer is lower than the adhesive force of the first adhesive layer.

Hereinafter, the adhesive sheet of the fifth aspect of the present invention will be described with reference to the drawings.

[Embodiment 1]
FIG. 51 is a cross-sectional view of the adhesive sheet 5 of the first embodiment. As shown in FIG. 51, the adhesive sheet 5 has a peripheral portion 54 formed by the first adhesive layer 50, and a central portion 53 inside the peripheral portion 54 has a large number of penetrations through the first adhesive layer 50. It is formed by lamination with a second layer 51 having a structure having holes and / or a non-woven structure as a skeleton. That is, the adhesive sheet 5 includes a second layer 51 and a first adhesive layer 50 that is laminated on the second layer 51 in such a manner as to cover the upper surface and side surfaces of the second layer 51. The adhesive force of the second layer 51 is lower than the adhesive force of the first adhesive layer 50.

The semiconductor wafer or the pedestal can be firmly fixed on the surface composed of only the first adhesive layer 50. The semiconductor wafer or the pedestal can be satisfactorily fixed on the surface having the first adhesive layer 50 and the second layer 51.

Since the adhesive sheet 5 has the second layer 51 having a low adhesive force, for example, the base is easily separated from the semiconductor wafer by an external force by cutting the first adhesive layer 50 or reducing the adhesive force. it can. Since the first adhesive layer 50 is formed in the peripheral portion 54, the adhesive sheet 5 is easy to cut the first adhesive layer 50 or reduce the adhesive force of the first adhesive layer 50, and is separated. Can be easily performed.

The thickness of the adhesive sheet 5 is not specifically limited, For example, it is 10 micrometers or more, Preferably it is 50 micrometers or more. When the thickness is 10 μm or more, the unevenness on the surface of the semiconductor wafer can be followed, and the adhesive sheet can be filled without a gap. Moreover, the thickness of the adhesive sheet 5 is 500 micrometers or less, for example, Preferably it is 300 micrometers or less. When the thickness is 500 μm or less, variation in thickness and shrinkage / expansion during heating can be suppressed or prevented.

FIG. 52 is a plan view of the adhesive sheet 5 according to the first embodiment. As shown in FIG. 52, the adhesive sheet 5 has a circular shape when viewed in plan.
The diameter of the adhesive sheet 5 is not particularly limited. For example, the diameter of the adhesive sheet 5 is preferably +1.0 to −1.0 mm with respect to the diameter of the pedestal.

Further, when the adhesive sheet 5 is viewed in plan, the shape of the second layer 51 is circular. The area of the second layer 51 when the adhesive sheet 5 is viewed in plan is preferably 10% or more, more preferably 20% or more with respect to the area of the adhesive sheet 5 when the adhesive sheet 5 is viewed in plan. Preferably it is 50% or more. If it is 10% or more, it is easy to cut the first adhesive layer 50 formed on the peripheral portion 54 or to reduce the adhesive force, and to easily separate the pedestal from the semiconductor wafer. The area of the second layer 51 is preferably 99.95% or less, more preferably 99.9% or less. A semiconductor wafer can be firmly fixed to a base as it is 99.95% or less.

The adhesive strength of the first adhesive layer 50 is preferably, for example, a 90 ° peel peel force on a silicon wafer under conditions of a temperature of 23 ± 2 ° C. and a peel speed of 300 mm / min is 0.30 N / 20 mm or more. 0.40 N / 20 mm or more is more preferable. When it is 0.30 N / 20 mm or more, the semiconductor wafer can be favorably held on the pedestal, and back grinding and the like can be favorably performed. The upper limit of the 90 ° peel peel force is not particularly limited and is preferably as large as possible. For example, it is 30 N / 20 mm or less, preferably 20 N / 20 mm or less.

As the adhesive composition constituting the first adhesive layer 50, the polyimide resin and silicone resin described in the first aspect of the present invention can be suitably used. Of these, polyimide resins are preferred from the viewpoints of heat resistance, chemical resistance, and adhesive residue.

The second layer 51 has a structure 57 having a large number of through holes 56 and / or a non-woven structure as a skeleton. FIG. 53 is a plan view of a structure 57 having a large number of through holes 56. As shown in FIG. 53, the through-hole 56 penetrates in the thickness direction of the structure 57 (also referred to as the thickness direction of the adhesive sheet 5).

The adhesive force of the second layer 51 can be adjusted by adjusting the aperture ratio of the structure 57 having a large number of through holes 56. Specifically, when the through hole 56 is filled with an adhesive composition described later, the adhesive force can be increased by increasing the aperture ratio, and the adhesive force can be decreased by decreasing the aperture ratio.
The porosity of the structure 57 is preferably 5% or more, more preferably 8% or more, and further preferably 10% or more. When it is 5% or more, the adhesive composition filled in the through holes 56 can reach the adherend, and the adhesive force of the second layer 51 can be adjusted.
The open area ratio is preferably 98% or less, more preferably 95% or less, and still more preferably 90% or less. When it is 98% or less, the adhesive force of the second layer 51 can be made lower than that of the first adhesive layer 50 even when the same adhesive composition as that of the first adhesive layer 50 is filled in the through holes 56.

In the structure 57, the shape of the through hole 56 (the shape of the through hole 56 when the adhesive sheet 5 is viewed in plan) is not particularly limited, and examples thereof include a circle, an ellipse, and a polygon. The shapes of the through holes 56 may all be the same or different.

When the adhesive sheet 5 is viewed in plan, the size (area) of one through hole 56 is preferably 70 μm ² or more, more preferably 100 μm ² or more. Further, it is preferably 20 mm ² or less, more preferably 7 mm ² or less. The sizes of the through holes 56 may all be the same or different.

The material of the structure 57 having a large number of through-holes 56 and the non-woven fabric structure is not particularly limited. For example, polyolefins such as low density polyethylene, linear polyethylene, medium density polyethylene, high density polyethylene, ultra low density polyethylene, random copolymer polypropylene, block copolymer polypropylene, homopolyprolene, polybutene, polymethylpentene, ethylene-acetic acid Vinyl copolymer, ionomer resin, ethylene- (meth) acrylic acid copolymer, ethylene- (meth) acrylic acid ester (random, alternating) copolymer, ethylene-butene copolymer, ethylene-hexene copolymer, Polyester such as polyurethane, polyethylene terephthalate, polyethylene naphthalate, polycarbonate, polyimide, polyetheretherketone, polyimide resin, polyetherimide, polyamide, wholly aromatic polyamide, polyphenyls Fuido, aramid (paper), glass, glass cloth, fluorine resin, polyvinyl chloride, polyvinylidene chloride, cellulose resin, silicone resin, paper and the like. In addition, metal materials such as iron, copper, nickel, tungsten, aluminum, gold, silver, copper, brass, red copper, phosphor bronze, nichrome, monel metal, bronze, and stainless steel (SUS) can be used. These may be used alone or in combination of two or more. Especially, when it is the structure 57 which has many through-holes 56, from a heat resistant point, a metal material, the above-mentioned polyimide resin, and the above-mentioned silicone resin are preferable, and SUS and aluminum are more preferable. In the case of a non-woven structure, the above-described polyimide resin, the above-described silicone resin, and metal material are preferable from the viewpoint of heat resistance and contamination.

The lower the adhesive strength of the structure 57 having a large number of through-holes 56 and the non-woven structure, the more preferable, for example, 90 ° peel peeling with respect to a silicon wafer under conditions of a temperature of 23 ± 2 ° C. and a peeling speed of 300 mm / min. The force is preferably less than 0.30 N / 20 mm, more preferably 0.20 N / 20 mm or less, and even more preferably 0.10 N / 20 mm or less. If the thickness is less than 0.30 N / 20 mm, the second layer 51 can be easily peeled off. The lower limit of the 90 ° peel peeling force is, for example, 0 N / 20 mm or more and 0.001 N / 20 mm or more.
When the structure 57 having a large number of through holes 56 and the non-woven structure are bonded by imidization or thermosetting, the 90 ° peel peeling force is fixed to the silicon wafer. The 90 ° peel peel force in a state (for example, after imidization or after thermosetting). Specifically, it can be measured by the method described in the examples.

The through-hole 56 and the porosity of the nonwoven fabric-like structure may be filled with the adhesive composition or may not be filled. It is preferable that the second layer having a low adhesive force can be easily formed by controlling the aperture ratio of the structure 57 and the density of the non-woven structure.

It does not specifically limit as an adhesive composition which fills the through-hole 56 or the porosity of a nonwoven fabric, For example, the above-mentioned polyimide resin, the above-mentioned silicone resin, etc. are mentioned.

The adhesive force of the second layer 51 is lower than the adhesive force of the first adhesive layer 50. The adhesive force of the second layer 51 is preferably, for example, a 90 ° peel peel force for a silicon wafer under a temperature of 23 ± 2 ° C. and a peel rate of 300 mm / min is less than 0.30 N / 20 mm. More preferably, it is 20 N / 20 mm or less. If the thickness is less than 0.30 N / 20 mm, the second layer 51 can be easily peeled off. The lower limit of the 90 ° peel peel force is preferably as low as possible, but is preferably 0 N / 20 mm or more, more preferably 0.001 N / 20 mm or more, still more preferably 0.01 N / 20 mm or more, and particularly preferably 0.10 N. / 20 mm or more.
The adhesive strength of the second layer 51 depends on the opening ratio of the structure 57, the density of the nonwoven structure, the type of the adhesive composition that fills the pores of the through holes 56 and the nonwoven fabric, the material of the structure 57, and the like. Can be adjusted.

As shown in FIG. 54, the adhesive sheet 5 may have other layers formed thereon. FIG. 54 is a cross-sectional view of the adhesive sheet 5 including the third layer 55. In the adhesive sheet 5 of FIG. 54, a third layer 55 is formed across the peripheral portion 54 and the central portion 53. The adhesive force of the third layer 55 is lower than the adhesive force of the first adhesive layer 50.

When the surface which consists only of the 3rd layer 55 is affixed on a semiconductor wafer or a base, the adhesive sheet 5 can be peeled easily. Further, the adhesive residue on the semiconductor wafer or the pedestal can be eliminated, and the cleaning process can be omitted.

The adhesive force of the third layer 55 is not particularly limited as long as it is lower than the adhesive force of the first adhesive layer 50. For example, the 90 ° peel peeling force for a silicon wafer under conditions of a temperature of 23 ± 2 ° C. and a peeling speed of 300 mm / min is preferably less than 0.30 N / 20 mm, and preferably 0.20 N / 20 mm or less. More preferred. When the thickness is less than 0.30 N / 20 mm, the adhesive can be peeled without residue, and the semiconductor wafer cleaning process can be omitted. Moreover, the minimum of this 90 degree peeling force is not specifically limited, For example, it is 0 N / 20mm or more, Preferably it is 0.001 N / 20mm or more. A semiconductor wafer can be hold | maintained to a base as it is 0 N / 20mm or more.

The material constituting the third layer 55 is not particularly limited as long as it is selected so that the adhesive force of the third layer 55 is lower than the adhesive force of the first adhesive layer 50. A polyimide resin and the above-mentioned silicone resin can be used suitably. Especially, the said polyimide resin is preferable from the point of heat resistance, chemical resistance, and adhesive residue.

The manufacturing method of the adhesive sheet 5 is not particularly limited. For example, a solution containing a composition for forming the first adhesive layer 50 is applied to the structure 57 having a large number of through-holes 56 and the periphery thereof (region around the structure 57), and the through-holes 56 are applied. And the coating layer is formed on the structure 57 and around the structure 57. In this method, the coating layer formed around the structure 57 becomes the first adhesive layer 50 in the peripheral portion 54.

In addition, when the second layer 51 has a non-woven structure as a skeleton, a solution containing the composition for forming the first adhesive layer 50 is applied to the non-woven structure and the periphery thereof, It can be manufactured by filling the pores of the non-woven structure with the solution and forming a coating layer on and around the structure. In this method, the coating layer formed around the structure becomes the first adhesive layer 50 in the peripheral portion 54.

The viscosity of the solution to be applied can be set as appropriate. What is necessary is just to set the application quantity suitably.

[Embodiment 2]
The adhesive sheet of the fifth aspect of the present invention is not limited to the shape of the adhesive sheet 5. FIG. 55 is a cross-sectional view of the adhesive sheet 6 of the second embodiment. FIG. 56 is a plan view of the adhesive sheet 6 according to the second embodiment. As shown in FIGS. 55 and 56, the adhesive sheet 6 has a structure in which the peripheral portion 64 is formed by the first adhesive layer 60 and the central portion 63 inside the peripheral portion 64 has a large number of through holes 66. A second layer 61 having a body as a skeleton is formed. The adhesive force of the second layer 61 is lower than the adhesive force of the first adhesive layer 60.

The second layer 61 may have a non-woven structure as a skeleton.

The semiconductor wafer or the pedestal can be satisfactorily fixed on the surface having the first adhesive layer 60 and the second layer 61.

Since the adhesive sheet 6 has the second layer 61 having a low adhesive force, for example, the base is easily separated from the semiconductor wafer by an external force by cutting the first adhesive layer 60 or reducing the adhesive force. it can. Since the first adhesive layer 60 is formed in the peripheral portion 64, the adhesive sheet 6 can be easily cut off or reduced in the adhesive strength of the first adhesive layer 60, and separated. Can be easily performed.

The thickness of the adhesive sheet 6 is not specifically limited, For example, what was illustrated by the adhesive sheet 5 of Embodiment 1 is mentioned.

As shown in FIG. 56, the adhesive sheet 6 has a circular shape when viewed in plan. The diameter of the adhesive sheet 6 is not specifically limited, For example, what was illustrated by the adhesive sheet 5 of Embodiment 1 is mentioned. Moreover, the area of the 2nd layer 61 when the adhesive sheet 6 is planarly viewed is not specifically limited, For example, what was illustrated with the adhesive sheet 5 of Embodiment 1 is mentioned.

Examples of the adhesive force of the first adhesive layer 60 include those exemplified for the first adhesive layer 50.
The description of the first adhesive layer 60 is the same as the content of the first adhesive layer 50.

Examples of the adhesive force of the second layer 61 include those exemplified for the second layer 51.
The description of the second layer 61 is the same as the content of the second layer 51.

The manufacturing method of the adhesive sheet 6 is not particularly limited. For example, a solution including a composition for forming the first adhesive layer 60 is applied to a structure having a large number of through-holes 66 and the periphery thereof (region around the structure), and the through-holes 66 are formed as described above. It can be manufactured by filling with a solution and forming a coating layer around the structure. In this method, the coating layer formed around the structure becomes the first adhesive layer 60 in the peripheral portion 64.

When the second layer 61 has a non-woven structure as a skeleton, a solution containing the composition for forming the first adhesive layer 60 is applied to the non-woven structure and the periphery thereof. It can be produced by filling the pores of the non-woven structure with the solution and forming a coating layer around the structure. In this method, the coating layer formed around the structure becomes the first adhesive layer 60 in the peripheral portion 64.

[Embodiment 3]
The adhesive sheet of the fifth aspect of the present invention is not limited to the shape of the

adhesive sheets

5 and 6. FIG. 57 is a cross-sectional view of the adhesive sheet 7 of the third embodiment. As shown in FIG. 57, the adhesive sheet 7 is formed by stacking a first adhesive layer 70 and a second layer 71 having a structure having a large number of through holes and / or a non-woven fabric structure as a skeleton. Has been. The adhesive force of the second layer 71 is lower than the adhesive force of the first adhesive layer 70.

Since the adhesive sheet 7 has the first adhesive layer 70, the semiconductor wafer can be satisfactorily fixed to the pedestal. Moreover, since it has the 2nd layer 71 whose adhesive force is lower than the 1st adhesive bond layer 70, a base can be easily isolate | separated from a semiconductor wafer with external force. For example, a method of cutting and separating the boundary between the first adhesive layer 70 and the second layer 71 may be used.

Examples of the adhesive force of the first adhesive layer 70 include those exemplified for the first adhesive layer 50.
The description of the first adhesive layer 70 is the same as the content of the first adhesive layer 50.

The adhesive strength of the second layer 71 is preferably, for example, a 90 ° peel peel force for a silicon wafer under a temperature of 23 ± 2 ° C. and a peel speed of 300 mm / min is less than 0.30 N / 20 mm. More preferably, it is 20 N / 20 mm or less. When it is less than 0.30 N / 20 mm, the pedestal can be easily separated from the semiconductor wafer. On the other hand, the lower limit of the 90 ° peel strength is preferably 0.001 N / 20 mm or more, more preferably 0.005 N / 20 mm or more, and still more preferably 0.010 N / 20 mm or more. When it is 0.001 N / 20 mm or more, the semiconductor wafer can be fixed to the pedestal well, and back grinding and the like can be performed well.

The description of the second layer 71 is the same as the content of the second layer 51.

The manufacturing method of the adhesive sheet 7 is not particularly limited. For example, a solution containing a composition for forming the first adhesive layer 70 is applied to a structure having a large number of through holes, the through holes are filled with the solution, and a coating layer is formed on the structure. Can be manufactured.

When the second layer 71 has a non-woven structure as a skeleton, a non-woven structure is applied to the non-woven structure by applying a solution containing the composition for forming the first adhesive layer 70. It can be manufactured by filling the pores of the structure with the solution and forming a coating layer on the structure.

In the above description, the adhesive sheets 5 to 7 having a circular shape in plan view have been described. However, the shape is not particularly limited, and may be another shape such as a polygon or an ellipse.

Further, the adhesive sheets 5 to 7 in which the shapes of the

second layers

51, 61, and 71 are circular when viewed in plan have been described. However, the shape is not particularly limited, and may be another shape such as a polygon or an ellipse.

The adhesive sheet for manufacturing a semiconductor device according to the fifth aspect of the present invention is used for fixing a semiconductor wafer to a pedestal. Specifically, it can be suitably used in a semiconductor device manufacturing method described later.

[Method for Manufacturing Semiconductor Device]
The manufacturing method of the semiconductor device of 5th this invention includes the process of fixing a semiconductor wafer to a base using an adhesive sheet, and the process of isolate | separating a base from a semiconductor wafer.

In the following description, the case where the adhesive sheet 5 of Embodiment 1 is used will be described. FIG. 58 is a schematic diagram illustrating a state in which the semiconductor wafer 3 is fixed to the base 1 using the adhesive sheet 5 of the first embodiment.

As the semiconductor wafer 3, the semiconductor wafer 3 described in the first aspect of the present invention can be preferably used. As the pedestal 1, the pedestal 1 described in the first aspect of the present invention can be suitably used.

The method of attaching (fixing) is not particularly limited, but pressure bonding is preferable. The crimping is usually performed while pressing with a pressing means such as a crimping roll. As the pressure bonding conditions, for example, 20 to 300 ° C., 0.001 to 10 MPa, and 0.001 to 10 mm / sec are preferable. The crimping time is usually 0.1 to 10 minutes.
After the pressure bonding, the first adhesive layer 50 is imidized as necessary. Thereby, the semiconductor wafer 3 can be favorably fixed to the base 1. Imidization can be performed by a conventionally known method, for example, imidization can be performed under conditions of 150 to 500 ° C. and 0.5 to 5 hours.
In addition to the imidization of the first adhesive layer 50, an adhesive composition filled in the pores of through holes and nonwoven fabrics may be imidized, and a structure having a large number of through holes or a nonwoven structure May be imidized.

Although the separation method is not particularly limited, a method of cutting and separating the first adhesive layer 50 and a method of separating by reducing the adhesive force of the first adhesive layer 50 are suitable.

The cutting method is not particularly limited, and examples thereof include a method of cutting the first adhesive layer 50 by cutting the first adhesive layer 50 from the side surface of the adhesive sheet 5 inward. The cutting can be performed by a conventionally known method such as a cutter or a laser.
The method for reducing the adhesive strength of the first adhesive layer 50 is not particularly limited, and the first adhesive layer 50 is formed of a method for dissolving the first adhesive layer 50 with a solvent or a material whose adhesive strength is reduced by heating. In addition, a method of reducing the adhesive force by heating, and the like can be mentioned.

Hereinafter, the first to fifth aspects of the present invention will be described in detail using examples. However, the first to fifth aspects of the present invention are not limited to the following examples as long as they do not exceed the gist thereof.

<< Embodiment of First Invention >>
The components used in the examples will be described.
PMDA: pyromellitic dianhydride (molecular weight: 218.1)
DDE: 4,4′-diaminodiphenyl ether (molecular weight: 200.2)
D-4000: Polyether diamine manufactured by Heinzmann (molecular weight: 4023.5)
DMAc: N, N-dimethylacetamide NMP: N-methyl-2-pyrrolidone D-2000: polyether diamine manufactured by Heinzmann (molecular weight: 1990.8)
BPDA: 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride PPD: p-phenylenediamine separator (long polyester film treated on one side with a silicone-based release agent: thickness 38 μm)
Long polyester film (thickness 25μm)

An adhesive sheet was produced by the following method.

Examples 1 and 5
<Preparation of First Adhesive Layer Solution and Second Layer Solution>
In an atmosphere under a nitrogen stream, 929.05 g of DMAc was mixed with D-4000 258.25 g, DDE 78.95 g, and PMDA 100 g at 70 ° C., and reacted to obtain a first adhesive layer solution (polyamide). An acid solution A) was obtained. The resulting first adhesive layer solution was cooled to room temperature (23 ° C.).
A second layer solution (polyamic acid solution B) was obtained in the same manner as the first adhesive layer solution except that the formulation in Table 1 was followed. The resulting second layer solution was cooled to room temperature (23 ° C.).
<Production of circular sheet>
The second layer solution was applied to the separator and dried at 90 ° C. for 3 minutes to obtain a sheet having the second layer.
A long polyester film is laminated on the second layer of the obtained sheet, half-cut with a Thomson mold to a diameter of 198 mm, and the outer part is left, leaving the punched part (the inner part punched with the Thomson mold). Removal gave a circular sheet. In addition, said half cut means the cut in the aspect which cuts a polyester film and a 2nd layer completely, and does not cut a separator completely (cut to the middle of a separator).
<Preparation of adhesive sheet>
The polyester film of the circular sheet was peeled off, and the first adhesive layer solution was applied on the second layer of the circular sheet so as to have a diameter of 200 mm or more, and dried at 90 ° C. for 3 minutes. A long polyester film was laminated on the dried first adhesive layer to obtain an adhesive sheet having the shape of Embodiment 1 shown in FIGS.
The entire adhesive sheet had a diameter of 200 mm and a thickness of 100 μm. The diameter of the second layer was 198 mm, and the thickness of the second layer was 2 μm. The thickness of the 1st adhesive bond layer in the center part of an adhesive sheet was 98 micrometers.

Example 2
<Preparation of first adhesive layer solution>
A first adhesive layer solution was obtained in the same manner as in Example 1 except that the composition according to Table 1 was followed.
<Preparation of adhesive sheet>
On a SUS foil (manufactured by Toyo Seikan Co., Ltd., SUS 304H-TA), Cu plating with a copper sulfate plating bath was performed so that the Cu film thickness was 0.5 μm to obtain a SUS foil with Cu plating. The obtained Cu-plated SUS foil was cooled to room temperature (23 ° C.).
The 1st adhesive layer solution of the mixing | blending of Table 1 was apply | coated to SUS foil with Cu plating, and it was dried at 90 degreeC for 2 minutes. Next, the SUS foil was peeled to obtain a polyamic acid layer with Cu plating. Cu etching was performed on the obtained polyamic acid layer with Cu plating. As a result, a circular (195 mm diameter) Cu plated portion (second layer) was left, and the others were removed. From the above, an adhesive sheet having the shape of Embodiment 1 shown in FIGS.
The entire adhesive sheet had a diameter of 200 mm and a thickness of 120 μm. The diameter of the second layer was 195 mm, and the thickness of the second layer was 0.5 μm. The thickness of the 1st adhesive bond layer in the center part of an adhesive sheet was 119.5 micrometers.
In Example 2, when the adhesive sheet is formed, a shape in which the second layer is formed on the first adhesive layer (a shape in which the first adhesive layer does not exist on the side surface side of the second layer). However, since the second layer is as thin as 0.5 μm, the first adhesive layer is as thick as 120 μm, and the first adhesive layer is relatively soft (low elastic modulus). Thus, the second layer is embedded in the first adhesive layer. Therefore, the adhesive sheet of Example 2 has the cross-sectional shape shown in FIG.

Example 3
An adhesive sheet was obtained in the same manner as in Example 1 except that the composition according to Table 1 was followed.

Example 4
<Production of circular sheet>
The second layer solution prepared in Example 1 was applied to a separator and dried at 90 ° C. for 3 minutes to obtain a sheet having a second layer.
A long polyester film is laminated on the second layer of the obtained sheet, half-cut with a Thomson mold to a diameter of 198 mm, and the outer part is left, leaving the punched part (the inner part punched with the Thomson mold). Removal was performed to obtain a circular sheet (thickness: 200 μm).
<Preparation of adhesive sheet>
The first adhesive layer solution prepared in Example 1 was applied to a separator and dried at 90 ° C. for 3 minutes to obtain a sheet having a first adhesive layer.
A long polyester film is laminated on the first adhesive layer of the obtained sheet, half-cut to 198 mm in diameter with a Thomson die, and the punched portion leaving the outside (inside punched with the Thomson die) Was removed to obtain a hollow sheet (thickness: 200 μm).
The separator of the circular sheet and the hollow sheet is peeled off and bonded so that the second layer of the circular sheet fits into the part where the first adhesive layer of the hollow sheet does not exist. An adhesive sheet having the shape of Embodiment 2 shown in FIG.
The entire adhesive sheet had a diameter of 200 mm and a thickness of 200 μm. The diameter of the second layer was 198 mm, and the thickness of the second layer was 200 μm.

Comparative Example 1
A single-layer adhesive sheet composed of the same first adhesive layer as in Example 1 was obtained. The adhesive sheet was circular and had a diameter of 200 mm and a thickness of 150 μm.

[Measurement of adhesive strength of first adhesive layer]
The first adhesive layer solution was applied to the separator and dried at 90 ° C. for 3 minutes to obtain a sheet having a first adhesive layer having a thickness of 20 μm.
The first adhesive layer of the obtained sheet was bonded to an 8-inch silicon wafer and imidized in a nitrogen atmosphere at 300 ° C. for 1.5 hours to obtain a first adhesive layer with a silicon wafer.
The first adhesive layer with a silicon wafer is processed to a width of 20 mm and a length of 100 mm, and a 90 ° peel evaluation is performed at a temperature of 23 ° C. and 300 mm / min using a tensile tester (manufactured by Shimadzu Corporation, Autograph AGS-H). went. The results are shown in Table 1.

[Measurement of adhesive strength of second layer]
The second layer solution was applied to the separator and dried at 90 ° C. for 3 minutes to obtain a sheet having a second layer having a thickness of 20 μm.
The second layer of the obtained sheet was bonded to an 8-inch silicon wafer and imidized in a nitrogen atmosphere at 300 ° C. for 1.5 hours to obtain a second layer with a silicon wafer.
A second layer with a silicon wafer is processed to a width of 20 mm and a length of 100 mm, and a 90 ° peel evaluation is performed using a tensile tester (manufactured by Shimadzu Corporation, Autograph AGS-H) at a temperature of 23 ° C. and 300 mm / min. It was. The results are shown in Table 1.
In addition, about the adhesive force of the 2nd layer of Example 2, 90 degree peel evaluation was performed using what bonded the 2nd layer to the 8-inch silicon wafer.

[Process resistance evaluation]
Examples 1 to 4
The surfaces on which the first adhesive layer and the second layer of the adhesive sheets of Examples 1 to 4 were exposed were attached to a pedestal (a silicon wafer having a diameter of 200 mm and a thickness of 726 μm). The pasting was performed by roll lamination at a temperature of 90 ° C. and a pressure of 0.1 MPa.
Next, the adhesive sheet surface of the adhesive sheet with a pedestal was attached to the circuit forming surface of a silicon wafer having a diameter of 200 mm and a thickness of 725 μm. The pasting was performed by roll lamination at a temperature of 90 ° C. and a pressure of 0.1 MPa. After pasting, the adhesive sheet was imidized in a nitrogen atmosphere at 300 ° C. for 1.5 hours. As a result, a laminated body in which the base, the adhesive sheet, and the silicon wafer were sequentially laminated was obtained.
Backgrinding was performed using the obtained laminate, and the case where the silicon wafer could be sufficiently fixed in the backgrind and satisfactorily background could be obtained. As evaluated.
Example 5
Process resistance was evaluated in the same manner as in Examples 1 to 4, except that the surface exposed only by the first adhesive layer was attached to the pedestal.
Comparative Example 1
A laminate was obtained by the same method as in Examples 1 to 4, and the process resistance was evaluated.
The results are shown in Table 1.

[Peelability evaluation]
A laminated body in which a pedestal, an adhesive sheet, and a silicon wafer were sequentially laminated was obtained by the same method as in the process resistance evaluation.
Using a Thomson blade, a cut was made inward from the side surface of the adhesive sheet layer. The cut was made until the second layer was reached. After cutting, the silicon wafer was adsorbed upward using vacuum tweezers arranged on the upper side (silicon wafer side) of the laminate. The case where it was able to adsorb | suck was evaluated as (circle) and the case where it was not able to adsorb was evaluated as x. The results are shown in Table 1.

In Examples 1 to 5, the silicon wafer could be sufficiently fixed and the back grinding could be performed satisfactorily. Moreover, the silicon wafer and the pedestal could be easily separated by cutting. On the other hand, Comparative Example 1 could not be peeled even when a cut was made in the adhesive sheet layer.

<< Example of Second Invention >>
The components used in the examples will be described.
PMDA: pyromellitic dianhydride (molecular weight: 218.1)
DDE: 4,4′-diaminodiphenyl ether (molecular weight: 200.2)
D-4000: Polyether diamine manufactured by Heinzmann (molecular weight: 4023.5)
DMAc: N, N-dimethylacetamide D-2000: Polyether diamine manufactured by Heinzmann (molecular weight: 1990.8)
BPDA: 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride PPD: p-phenylenediamine separator (long polyester film treated on one side with a silicone-based release agent: thickness 38 μm)

An adhesive sheet was produced by the following method.

Example 1
In an atmosphere under a nitrogen stream, D-4000 239.8 g, DDE 79.9 g, and PMDA 100.0 g were mixed and reacted at 1912.0 g of DMAc at 70 ° C. to obtain a first adhesive layer solution (Polyamic acid solution A) was obtained. The resulting first adhesive layer solution was cooled to room temperature (23 ° C.).
A second layer solution (polyamic acid solution B) was obtained in the same manner as the first adhesive layer solution except that the composition in Table 2 was followed. The resulting second layer solution was cooled to room temperature (23 ° C.).
The second layer solution was applied to the separator and dried at 90 ° C. for 3 minutes to obtain a sheet having the second layer. On the obtained sheet, the first adhesive layer solution was applied and dried at 90 ° C. for 3 minutes to form a first adhesive layer. As a result, an adhesive sheet in which the first adhesive layer and the second layer were laminated was obtained.
The entire diameter of the adhesive sheet was 200 mm, and the thickness was 100 μm.
The diameter of the first adhesive layer was 200 mm, and the thickness was 90 μm.
The diameter of the second layer was 200 mm and the thickness was 10 μm.

Examples 2 to 3
An adhesive sheet was obtained in the same manner as in Example 1 except that the composition according to Table 2 was followed.

Comparative Example 1
Using the first adhesive layer solution of Example 1, an adhesive sheet (single layer) composed of the first adhesive layer was obtained. The adhesive sheet was circular and had a diameter of 200 mm and a thickness of 150 μm.

[Measurement of adhesive strength of first adhesive layer]
The first adhesive layer solution was applied to the separator and dried at 90 ° C. for 3 minutes to obtain a sheet having a first adhesive layer having a thickness of 20 μm.
The first adhesive layer of the obtained sheet was bonded to an 8-inch silicon wafer and imidized in a nitrogen atmosphere at 300 ° C. for 1.5 hours to obtain a first adhesive layer with a silicon wafer.
The first adhesive layer with a silicon wafer is processed to a width of 20 mm and a length of 100 mm, and a 90 ° peel evaluation is performed at a temperature of 23 ° C. and 300 mm / min using a tensile tester (manufactured by Shimadzu Corporation, Autograph AGS-H). went. The results are shown in Table 2.

[Measurement of adhesive strength of second layer]
The second layer solution was applied to the separator and dried at 90 ° C. for 3 minutes to obtain a sheet having a second layer having a thickness of 20 μm.
The second layer of the obtained sheet was bonded to an 8-inch silicon wafer and imidized in a nitrogen atmosphere at 300 ° C. for 1.5 hours to obtain a second layer with a silicon wafer.
A second layer with a silicon wafer is processed to a width of 20 mm and a length of 100 mm, and a 90 ° peel evaluation is performed using a tensile tester (manufactured by Shimadzu Corporation, Autograph AGS-H) at a temperature of 23 ° C. and 300 mm / min. It was. The results are shown in Table 2.

[Process resistance evaluation]
Examples 1 to 3
The second layer of the adhesive sheets of Examples 1 to 3 was attached to a pedestal (a silicon wafer having a diameter of 200 mm and a thickness of 726 μm). The pasting was performed by roll lamination at a temperature of 90 ° C. and a pressure of 0.1 MPa.
Next, the adhesive sheet surface of the adhesive sheet with a pedestal was attached to the circuit forming surface of a silicon wafer having a diameter of 200 mm and a thickness of 725 μm. The pasting was performed by roll lamination at a temperature of 90 ° C. and a pressure of 0.1 MPa. After pasting, the adhesive sheet was imidized in a nitrogen atmosphere at 300 ° C. for 1.5 hours. As a result, a laminated body in which the pedestal, the adhesive sheet, and the silicon wafer were sequentially laminated was obtained.
Backgrinding was performed using the obtained laminate, and the case where the silicon wafer could be sufficiently fixed in the backgrind and satisfactorily background could be obtained. As evaluated.
Comparative Example 1
A laminate was obtained by the same method as in Examples 1 to 3, and the process resistance was evaluated.
The results are shown in Table 2.

[Peelability evaluation]
A laminated body in which a pedestal, an adhesive sheet, and a silicon wafer were sequentially laminated was obtained by the same method as in the process resistance evaluation.
A cut was made at the boundary between the first adhesive layer and the second layer using a Thomson blade (1 mm cut from the edge of the silicon wafer). After cutting, the silicon wafer was adsorbed upward using vacuum tweezers arranged on the silicon wafer side of the laminate. The case where the first adhesive layer with a silicon wafer was peeled from the laminate by adsorption was evaluated as ◯, and the case where the first adhesive layer was not peeled was evaluated as x. The results are shown in Table 2.

<< Example of Third Invention >>
The components used in the examples will be described.
PMDA: pyromellitic dianhydride (molecular weight: 218.1)
DDE: 4,4′-diaminodiphenyl ether (molecular weight: 200.2)
D-4000: Polyether diamine manufactured by Heinzmann (molecular weight: 4023.5)
DMAc: N, N-dimethylacetamide BPDA: 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride PPD: p-phenylenediamine NMP: N-methyl-2-pyrrolidone SD4587L: Toray Dow Corning ) Made silicone adhesive (addition curing type)
SRX-212: Platinum catalyst separator manufactured by Toray Dow Corning Co., Ltd. (long polyester film treated on one side with a silicone-based release agent: thickness 38 μm)

[Preparation of solution for sheet and adhesive layer]
Example 1
In an atmosphere under a nitrogen stream, D-4000 29.5 g, DDE 90.3 g, and PMDA 100.0 g were mixed and reacted at 2528.0 g of DMAc at 70 ° C. to obtain a sheet solution (polyamic acid solution). A) was obtained. The obtained sheet solution was cooled to room temperature (23 ° C.). The sheet solution was applied to the separator and dried at 90 ° C. for 3 minutes to obtain a sheet.
The obtained sheet had a diameter of 200 mm and a thickness of 100 μm.
An adhesive layer solution (polyamic acid solution B) was obtained in the same manner as the sheet solution except that the composition in Table 3 was followed. The obtained adhesive layer solution was cooled to room temperature (23 ° C.).

Examples 2-3 and Comparative Example 1
A sheet and an adhesive layer solution were obtained in the same manner as in Example 1 except that the composition according to Table 3 was followed.

[Measurement of adhesive strength of sheet]
The sheet solution was applied to the separator and dried at 90 ° C. for 3 minutes to obtain a sample sheet 1 having a thickness of 20 μm. The obtained sample sheet 1 was bonded to an 8-inch silicon wafer and imidized in a nitrogen atmosphere at 300 ° C. for 1.5 hours to obtain a sample sheet 1 with a silicon wafer. Sample sheet 1 with a silicon wafer was processed to a width of 20 mm and a length of 100 mm, and a 90 ° peel evaluation was performed using a tensile tester (manufactured by Shimadzu Corporation, Autograph AGS-H) at a temperature of 23 ° C. and 300 mm / min. . The results are shown in Table 3.

[Measurement of adhesive strength of adhesive layer]
The adhesive layer solution was applied to a separator and dried at 90 ° C. for 3 minutes to obtain a sample sheet 2 having a thickness of 20 μm. The obtained sample sheet 2 was bonded to an 8-inch silicon wafer, and then imidized (Example 1, Comparative Example 1) or thermally cured (Examples 2 and 3).
The imidization was performed in a nitrogen atmosphere at 300 ° C. for 1.5 hours.
Thermosetting was performed at 150 ° C. for 1 hour in an air atmosphere.
The sample sheet 2 with silicon wafer thus obtained was processed into a width of 20 mm and a length of 100 mm, and 90 ° at a temperature of 23 ° C. and 300 mm / min using a tensile tester (manufactured by Shimadzu Corp., Autograph AGS-H). Peel evaluation was performed. The results are shown in Table 3.

[Process resistance evaluation]
Example 1
The sheet was attached to a circuit forming surface of a silicon wafer having a bevel portion having a diameter of 200 mm and a thickness of 725 μm. The pasting was performed by roll lamination at a temperature of 90 ° C. and a pressure of 0.1 MPa. After pasting, the sheet was imidized in a nitrogen atmosphere at 300 ° C. for 1.5 hours.
A pedestal (a silicon wafer having a diameter of 200 mm and a thickness of 726 μm) having a bevel portion was attached to the back surface of the sheet surface to which the silicon wafer was attached. Pasting was performed at a temperature of 120 ° C. and a pressure of 0.3 MPa.
Next, an adhesive layer solution was applied between the sheet and the pedestal bevel, dried and imidized to form an adhesive layer. Thereby, the sheet was fixed to the pedestal.
As described above, a laminate in which the pedestal, the sheet, and the silicon wafer were sequentially laminated was obtained.
Backgrinding was performed using the obtained laminate, and the case where the silicon wafer could be sufficiently fixed in the backgrind and satisfactorily background could be obtained. As evaluated.
Examples 2 to 3
Instead of imidization, a laminate was obtained in the same manner as in Example 1 except that the adhesive layer was thermally cured at 150 ° C. for 1 hour in the air atmosphere. Evaluation was performed in the same manner as in Example 1 using the obtained laminate.
Comparative Example 1
A laminate was obtained in the same manner as in Example 1 except that the adhesive layer solution was not applied. Evaluation was performed in the same manner as in Example 1 using the obtained laminate. The results are shown in Table 3.

[Peelability evaluation]
A laminate was obtained by the same method as in the process resistance evaluation.
As shown in FIG. 22, the sheet was cut from the side of the sheet until it reached the bevel portion of the pedestal 1 (the depth of cut was 0.5 mm).
After cutting, the silicon wafer was adsorbed upward using vacuum tweezers arranged on the silicon wafer side of the laminate. The case where the sheet with the silicon wafer could be peeled from the laminate by adsorption was evaluated as ◯, and the case where the sheet was not peeled was evaluated as x. The results are shown in Table 3.

<< Example of Fourth Invention >>
The components used in the examples will be described.
PMDA: pyromellitic dianhydride (molecular weight: 218.1)
DDE: 4,4′-diaminodiphenyl ether (molecular weight: 200.2)
D-4000: Polyether diamine manufactured by Heinzmann (molecular weight: 4023.5)
DMAc: N, N-dimethylacetamide NMP: N-methyl-2-pyrrolidone D-2000: polyether diamine manufactured by Heinzmann (molecular weight: 1990.8)
BPDA: 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride PPD: p-phenylenediamine SD4587L: silicone adhesive manufactured by Toray Dow Corning (addition curing type)
SRX-212: Platinum catalyst separator manufactured by Toray Dow Corning Co., Ltd. (long polyester film treated on one side with a silicone-based release agent: thickness 38 μm)
Long polyester film (thickness 25μm)

Examples 1 to 5 and Comparative Example 1 will be described.

An adhesive sheet was produced by the following method.

Examples 1 and 5
<Preparation of First Adhesive Layer Solution and Second Layer Solution>
In an atmosphere under a nitrogen stream, 929.05 g of DMAc was mixed with D-4000 258.25 g, DDE 78.95 g, and PMDA 100 g at 70 ° C., and reacted to obtain a first adhesive layer solution (polyamide). An acid solution A) was obtained. The resulting first adhesive layer solution was cooled to room temperature (23 ° C.).
A second layer solution (polyamic acid solution B) was obtained in the same manner as the first adhesive layer solution except that the composition according to Table 4 was followed. The resulting second layer solution was cooled to room temperature (23 ° C.).
<Production of circular sheet>
The second layer solution was applied to the separator and dried at 90 ° C. for 3 minutes to obtain a sheet having the second layer.
A long polyester film is laminated on the second layer of the obtained sheet, half-cut with a Thomson mold to a diameter of 198 mm, and the outer part is left, leaving the punched part (the inner part punched with the Thomson mold). Removal gave a circular sheet. In addition, said half cut means the cut in the aspect which cuts a polyester film and a 2nd layer completely, and does not cut a separator completely (cut to the middle of a separator).
<Preparation of adhesive sheet>
The polyester film of the circular sheet was peeled off, and the first adhesive layer solution was applied on the second layer of the circular sheet so as to have a diameter of 200 mm or more, and dried at 90 ° C. for 3 minutes. A long polyester film was laminated on the dried first adhesive layer to obtain an adhesive sheet having the shape shown in FIGS.
The entire adhesive sheet had a diameter of 200 mm and a thickness of 100 μm. The diameter of the second layer was 198 mm, and the thickness of the second layer was 2 μm. The thickness of the 1st adhesive bond layer in the center part of an adhesive sheet was 98 micrometers.

Example 2
<Preparation of first adhesive layer solution>
A first adhesive layer solution was obtained in the same manner as in Example 1 except that the composition according to Table 4 was followed.
<Preparation of adhesive sheet>
On a SUS foil (manufactured by Toyo Seikan Co., Ltd., SUS 304H-TA), Cu plating with a copper sulfate plating bath was performed so that the Cu film thickness was 0.5 μm to obtain a SUS foil with Cu plating. The obtained Cu-plated SUS foil was cooled to room temperature (23 ° C.).
The first adhesive layer solution having the composition shown in Table 4 was applied to a Cu-plated SUS foil and dried at 90 ° C. for 2 minutes. Next, the SUS foil was peeled to obtain a polyamic acid layer with Cu plating. Cu etching was performed on the obtained polyamic acid layer with Cu plating. As a result, a circular (195 mm diameter) Cu plated portion (second layer) was left, and the others were removed. From the above, an adhesive sheet having the shape shown in FIGS. 24 and 25 was obtained.
The entire adhesive sheet had a diameter of 200 mm and a thickness of 120 μm. The diameter of the second layer was 195 mm, and the thickness of the second layer was 0.5 μm. The thickness of the 1st adhesive bond layer in the center part of an adhesive sheet was 119.5 micrometers.
In Example 2, when the adhesive sheet is formed, a shape in which the second layer is formed on the first adhesive layer (a shape in which the first adhesive layer does not exist on the side surface side of the second layer). However, since the second layer is as thin as 0.5 μm, the first adhesive layer is as thick as 120 μm, and the first adhesive layer is relatively soft (low elastic modulus). Thus, the second layer is embedded in the first adhesive layer. Therefore, the adhesive sheet of Example 2 has the cross-sectional shape shown in FIG.

Example 3
An adhesive sheet was obtained in the same manner as in Example 1 except that the composition according to Table 4 was followed.

Example 4
<Production of circular sheet>
The second layer solution prepared in Example 1 was applied to a separator and dried at 90 ° C. for 3 minutes to obtain a sheet having a second layer.
A long polyester film is laminated on the second layer of the obtained sheet, half-cut with a Thomson mold to a diameter of 198 mm, and the outer part is left, leaving the punched part (the inner part punched with the Thomson mold). Removal was performed to obtain a circular sheet (thickness: 200 μm).
<Preparation of adhesive sheet>
The first adhesive layer solution prepared in Example 1 was applied to a separator and dried at 90 ° C. for 3 minutes to obtain a sheet having a first adhesive layer.
A long polyester film is laminated on the first adhesive layer of the obtained sheet, half-cut to 198 mm in diameter with a Thomson die, and the punched portion leaving the outside (inside punched with the Thomson die) Was removed to obtain a hollow sheet (thickness: 200 μm).
29 and 30, the separator of the circular sheet and the hollow sheet is peeled off and bonded so that the second layer of the circular sheet fits into the part where the first adhesive layer of the hollow sheet does not exist. An adhesive sheet having the shape shown in FIG.
The entire adhesive sheet had a diameter of 200 mm and a thickness of 200 μm. The diameter of the second layer was 198 mm, and the thickness of the second layer was 200 μm.

[Measurement of adhesive strength of first adhesive layer]
The first adhesive layer solution was applied to the separator and dried at 90 ° C. for 3 minutes to obtain a sheet having a first adhesive layer having a thickness of 20 μm.
The first adhesive layer of the obtained sheet was bonded to an 8-inch silicon wafer and imidized in a nitrogen atmosphere at 300 ° C. for 1.5 hours to obtain a first adhesive layer with a silicon wafer.
The first adhesive layer with a silicon wafer is processed to a width of 20 mm and a length of 100 mm, and a 90 ° peel evaluation is performed at a temperature of 23 ° C. and 300 mm / min using a tensile tester (manufactured by Shimadzu Corporation, Autograph AGS-H). went. The results are shown in Table 4.

[Measurement of adhesive strength of second layer]
The second layer solution was applied to the separator and dried at 90 ° C. for 3 minutes to obtain a sheet having a second layer having a thickness of 20 μm.
The second layer of the obtained sheet was bonded to an 8-inch silicon wafer and imidized in a nitrogen atmosphere at 300 ° C. for 1.5 hours to obtain a second layer with a silicon wafer.
A second layer with a silicon wafer is processed to a width of 20 mm and a length of 100 mm, and a 90 ° peel evaluation is performed using a tensile tester (manufactured by Shimadzu Corporation, Autograph AGS-H) at a temperature of 23 ° C. and 300 mm / min. It was. The results are shown in Table 4.
In addition, about the adhesive force of the 2nd layer of Example 2, 90 degree peel evaluation was performed using what bonded the 2nd layer to the 8-inch silicon wafer.

[Process resistance evaluation (1)]
Examples 1 to 4
The surfaces on which the first adhesive layer and the second layer of the adhesive sheets of Examples 1 to 4 were exposed were attached to a pedestal (a silicon wafer having a diameter of 200 mm and a thickness of 726 μm). The pasting was performed by roll lamination at a temperature of 90 ° C. and a pressure of 0.1 MPa.
Next, the adhesive sheet surface of the adhesive sheet with a pedestal was attached to the circuit forming surface of a silicon wafer having a diameter of 200 mm and a thickness of 725 μm. The pasting was performed by roll lamination at a temperature of 90 ° C. and a pressure of 0.1 MPa. After pasting, the adhesive sheet was imidized in a nitrogen atmosphere at 300 ° C. for 1.5 hours. As a result, a laminated body in which the pedestal, the adhesive sheet, and the silicon wafer were sequentially laminated was obtained.
Backgrinding was performed using the obtained laminate, and the case where the silicon wafer could be sufficiently fixed in the backgrind and satisfactorily background could be obtained. As evaluated.
Example 5
Process resistance was evaluated in the same manner as in Examples 1 to 4, except that the surface exposed only by the first adhesive layer was attached to the pedestal.
Comparative Example 1
A laminate was obtained by the same method as in Examples 1 to 4, and the process resistance was evaluated.
The results are shown in Table 4.

[Peelability evaluation (1)]
Examples 1 to 5, Comparative Example 1
A laminated body in which a pedestal, an adhesive sheet, and a silicon wafer were sequentially laminated was obtained by the same method as in the process resistance evaluation.
Using a Thomson blade, a cut was made inward from the side surface of the adhesive sheet layer. The cut was made until the second layer was reached. After cutting, the silicon wafer was adsorbed upward using vacuum tweezers arranged on the upper side (silicon wafer side) of the laminate. The case where it was able to adsorb | suck was evaluated as (circle) and the case where it was not able to adsorb was evaluated as x. The results are shown in Table 4.

Examples 6 to 8 and Comparative Example 2 will be described.

Example 6
In an atmosphere under a nitrogen stream, D-4000 239.8 g, DDE 79.9 g, and PMDA 100.0 g were mixed and reacted at 1912.0 g of DMAc at 70 ° C. to obtain a first adhesive layer solution Got. The resulting first adhesive layer solution was cooled to room temperature (23 ° C.).
A second layer solution was obtained in the same manner as the first adhesive layer solution except that the composition in Table 5 was followed. The resulting second layer solution was cooled to room temperature (23 ° C.).
The second layer solution was applied to the separator and dried at 90 ° C. for 3 minutes to obtain a sheet having the second layer. On the obtained sheet, the first adhesive layer solution was applied and dried at 90 ° C. for 3 minutes to form a first adhesive layer. This obtained the adhesive sheet (adhesive sheet of the shape shown in FIG. 33) by which the 1st adhesive bond layer and the 2nd layer were laminated | stacked.
The entire diameter of the adhesive sheet was 200 mm, and the thickness was 100 μm.
The diameter of the first adhesive layer was 200 mm, and the thickness was 90 μm.
The diameter of the second layer was 200 mm and the thickness was 10 μm.

Examples 7-8
An adhesive sheet was obtained in the same manner as in Example 6 except that the composition according to Table 5 was followed.

Comparative Example 2
Using the first adhesive layer solution of Example 6, an adhesive sheet (single layer) composed of the first adhesive layer was obtained. The adhesive sheet was circular and had a diameter of 200 mm and a thickness of 150 μm.

[Measurement of adhesive strength of first adhesive layer]
Measurement was performed by the method described above. The results are shown in Table 5.
[Measurement of adhesive strength of second layer]
Measurement was performed by the method described above. The results are shown in Table 5.

[Process resistance evaluation (2)]
Examples 6-8, Comparative Example 2
The second layer of the adhesive sheets of Examples 6 to 8 was attached to a pedestal (a silicon wafer having a diameter of 200 mm and a thickness of 726 μm). The pasting was performed by roll lamination at a temperature of 90 ° C. and a pressure of 0.1 MPa.
Next, the adhesive sheet surface of the adhesive sheet with a pedestal was attached to the circuit forming surface of a silicon wafer having a diameter of 200 mm and a thickness of 725 μm. The pasting was performed by roll lamination at a temperature of 90 ° C. and a pressure of 0.1 MPa. After pasting, the adhesive sheet was imidized in a nitrogen atmosphere at 300 ° C. for 1.5 hours. As a result, a laminated body in which the pedestal, the adhesive sheet, and the silicon wafer were sequentially laminated was obtained.
Backgrinding was performed using the obtained laminate, and the case where the silicon wafer could be sufficiently fixed in the backgrind and satisfactorily background could be obtained. As evaluated.
For Comparative Example 2, a laminate was obtained by the same method, and the process resistance was evaluated.
The results are shown in Table 5.

[Peelability evaluation (2)]
Examples 6-8, Comparative Example 2
A laminated body in which a pedestal, an adhesive sheet, and a silicon wafer were sequentially laminated was obtained by the same method as in the process resistance evaluation.
A cut was made at the boundary between the first adhesive layer and the second layer using a Thomson blade (1 mm cut from the edge of the silicon wafer). After cutting, the silicon wafer was adsorbed upward using vacuum tweezers arranged on the silicon wafer side of the laminate. The case where the first adhesive layer with a silicon wafer was peeled from the laminate by adsorption was evaluated as ◯, and the case where the first adhesive layer was not peeled was evaluated as x. The results are shown in Table 5.

Examples 9 to 11 and Comparative Example 3 will be described.

[Preparation of solution for sheet and adhesive layer]
Example 9
In an atmosphere under a nitrogen stream, D-4000 29.5 g, DDE 90.3 g, and PMDA 100.0 g were mixed and reacted at 2528.0 g of DMAc at 70 ° C. to obtain a sheet solution. The obtained sheet solution was cooled to room temperature (23 ° C.). The sheet solution was applied to the separator and dried at 90 ° C. for 3 minutes to obtain a sheet.
The obtained sheet had a diameter of 200 mm and a thickness of 100 μm.
An adhesive layer solution was obtained in the same manner as the sheet solution except that the composition in Table 6 was followed. The obtained adhesive layer solution was cooled to room temperature (23 ° C.).

Examples 10-11, Comparative Example 3
A sheet and an adhesive layer solution were obtained in the same manner as in Example 9 except that the composition according to Table 6 was followed.

[Measurement of adhesive strength of sheet]
The sheet solution was applied to the separator and dried at 90 ° C. for 3 minutes to obtain a sample sheet 1 having a thickness of 20 μm. The obtained sample sheet 1 was bonded to an 8-inch silicon wafer and imidized in a nitrogen atmosphere at 300 ° C. for 1.5 hours to obtain a sample sheet 1 with a silicon wafer. Sample sheet 1 with a silicon wafer was processed to a width of 20 mm and a length of 100 mm, and a 90 ° peel evaluation was performed using a tensile tester (manufactured by Shimadzu Corporation, Autograph AGS-H) at a temperature of 23 ° C. and 300 mm / min. . The results are shown in Table 6.

[Measurement of adhesive strength of adhesive layer]
The adhesive layer solution was applied to a separator and dried at 90 ° C. for 3 minutes to obtain a sample sheet 2 having a thickness of 20 μm. The obtained sample sheet 2 was bonded to an 8-inch silicon wafer, and then imidized (Example 9, Comparative Example 3) or thermally cured (Examples 10 and 11).
The imidization was performed in a nitrogen atmosphere at 300 ° C. for 1.5 hours.
Thermosetting was performed at 150 ° C. for 1 hour in an air atmosphere.
The sample sheet 2 with silicon wafer thus obtained was processed into a width of 20 mm and a length of 100 mm, and 90 ° at a temperature of 23 ° C. and 300 mm / min using a tensile tester (manufactured by Shimadzu Corp., Autograph AGS-H). Peel evaluation was performed. The results are shown in Table 6.

[Process resistance evaluation (3)]
Example 9
The sheet was attached to a circuit forming surface of a silicon wafer having a bevel portion having a diameter of 200 mm and a thickness of 725 μm. The pasting was performed by roll lamination at a temperature of 90 ° C. and a pressure of 0.1 MPa. After pasting, the sheet was imidized in a nitrogen atmosphere at 300 ° C. for 1.5 hours.
A pedestal (a silicon wafer having a diameter of 200 mm and a thickness of 726 μm) having a bevel portion was attached to the back surface of the sheet surface to which the silicon wafer was attached. Pasting was performed at a temperature of 120 ° C. and a pressure of 0.3 MPa.
Next, an adhesive layer solution was applied between the sheet and the pedestal bevel and dried to form a temporary adhesive layer. Thereby, the sheet was fixed to the pedestal.
As described above, a laminate in which the pedestal, the sheet, and the silicon wafer were sequentially laminated was obtained.
Backgrinding was performed using the obtained laminate, and the case where the silicon wafer could be sufficiently fixed in the backgrind and satisfactorily background could be obtained. As evaluated.
Examples 10-11
Instead of imidization, a laminate was obtained in the same manner as in Example 9 except that the adhesive layer was thermally cured at 150 ° C. for 1 hour in an air atmosphere. Evaluation was performed in the same manner as in Example 9 using the obtained laminate.
Comparative Example 3
A laminate was obtained in the same manner as in Example 9 except that the adhesive layer solution was not applied. Evaluation was performed in the same manner as in Example 9 using the obtained laminate.
The results are shown in Table 6.

[Peelability evaluation (3)]
A laminate was obtained by the same method as in the process resistance evaluation.
As shown in FIG. 49, the sheet was cut from the side of the sheet until it reached the bevel portion of the pedestal 35 (cut depth: 0.5 mm).
After cutting, the silicon wafer was adsorbed upward using vacuum tweezers arranged on the silicon wafer side of the laminate. The case where the sheet with the silicon wafer could be peeled from the laminate by adsorption was evaluated as ◯, and the case where the sheet was not peeled was evaluated as x. The results are shown in Table 6.

<< Example of Fifth Invention >>
The components used in the examples will be described.
PMDA: pyromellitic dianhydride (molecular weight: 218.1)
DDE: 4,4′-diaminodiphenyl ether (molecular weight: 200.2)
D-4000: Polyether diamine manufactured by Heinzmann (molecular weight: 4023.5)
DMAc: N, N-dimethylacetamide NMP: N-methyl-2-pyrrolidone D-2000: polyether diamine manufactured by Heinzmann (molecular weight: 1990.8)
BPDA: 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride PPD: p-phenylenediamine separator (long polyester film treated on one side with a silicone release agent)

Example 1
In an atmosphere under a nitrogen stream, D-4000 365 g, DDE 74 g, and PMDA 100 g were mixed and reacted at 70 ° C. in 1257 g of DMAc, and then cooled to room temperature (23 ° C.). An adhesive solution was obtained.
A second adhesive solution was obtained in the same manner as the first adhesive solution except that the composition according to Table 7 was followed. The second adhesive solution is applied to the separator and dried at 90 ° C. for 3 minutes to produce a sheet having a coating layer of the second adhesive solution. A sheet was obtained. The shape of the through hole when the perforated sheet was viewed in plan was circular, and the area of each through hole when the perforated sheet was viewed in plan was 78.5 μm ² . The diameter of each through hole was 10 μm. The aperture ratio was 50%.
The first adhesive solution was applied to the perforated sheet and its periphery (region around the perforated sheet), the through holes were filled with the first adhesive solution, and an application layer of the first adhesive solution was formed. Then, it was made to dry for 3 minutes at 90 degreeC, and the adhesive sheet of the shape of Embodiment 1 shown to FIG.
The entire adhesive sheet had a diameter of 200 mm and a thickness of 100 μm.
The diameter of the second layer was 196 mm, and the thickness of the second layer was 1 μm.
The thickness of the 1st adhesive bond layer in the center part of the adhesive sheet was 99 micrometers.

Example 2
A first adhesive solution was obtained in the same manner as in Example 1 except that the composition according to Table 7 was followed.
An adhesive sheet having the shape of Embodiment 1 shown in FIGS. 51 and 52 was obtained in the same manner as in Example 1 except that an aluminum mesh having an aperture ratio of 80% was used instead of the perforated sheet.
The entire adhesive sheet had a diameter of 200 mm and a thickness of 120.5 μm.
The diameter of the second layer was 198 mm, and the thickness of the second layer was 0.5 μm.
The thickness of the 1st adhesive bond layer in the center part of the adhesive sheet was 120 micrometers.

Example 3
The point which obtained the 1st adhesive solution and the 2nd adhesive solution according to the composition of Table 7, the shape of the through hole when the perforated sheet is viewed in plan, and the area of each through hole are 7.0 mm ² The adhesive sheet having the shape of Embodiment 1 shown in FIGS. 51 and 52 was obtained in the same manner as in Example 1 except that the opening ratio was 10%.
The entire adhesive sheet had a diameter of 200 mm and a thickness of 100 μm.
The diameter of the second layer was 197 mm, and the thickness of the second layer was 1 μm.
The thickness of the 1st adhesive bond layer in the center part of the adhesive sheet was 99 micrometers.

Comparative Example 1
A first adhesive solution was obtained in the same manner as in Example 1 except that the composition according to Table 7 was followed.
The first adhesive solution was applied to the separator and dried at 90 ° C. for 3 minutes to obtain a single-layer adhesive sheet made of the first adhesive. The adhesive sheet was circular and had a diameter of 200 mm and a thickness of 150 μm.

[Measurement of adhesive strength of first adhesive layer]
The surface consisting only of the first adhesive layer (the first adhesive solution coating layer) of the adhesive sheet was bonded to an 8-inch silicon wafer and imidized in a nitrogen atmosphere at 300 ° C. for 1.5 hours to form silicon. An adhesive sheet with a wafer was obtained.
The adhesive sheet with a silicon wafer was processed into a width of 20 mm and a length of 100 mm, and a 90 ° peel evaluation was performed using a tensile tester (manufactured by Shimadzu Corporation, Autograph AGS-H) at a temperature of 23 ° C. and 300 mm / min. The results are shown in Table 7.

[Measurement of adhesive strength of perforated sheet and aluminum mesh (structure with many through holes)]
Examples 1 and 3
The perforated sheets of Examples 1 and 3 were bonded to an 8-inch silicon wafer and imidized in a nitrogen atmosphere at 300 ° C. for 1.5 hours to obtain a perforated sheet with a silicon wafer.
A perforated sheet with a silicon wafer was processed to a width of 20 mm and a length of 100 mm, and a 90 ° peel evaluation was performed using a tensile tester (manufactured by Shimadzu Corporation, Autograph AGS-H) at a temperature of 23 ° C. and 300 mm / min. . The results are shown in Table 7.
Example 2
The aluminum mesh was bonded to an 8-inch silicon wafer to obtain an aluminum mesh with a silicon wafer. The obtained aluminum mesh with a silicon wafer was processed into a width of 20 mm and a length of 100 mm, and a 90 ° peel evaluation was performed at a temperature of 23 ° C. and 300 mm / min using a tensile tester (manufactured by Shimadzu Corp., Autograph AGS-H). went. The results are shown in Table 7.

[Measurement of adhesive strength of second layer]
A second layer (a second layer comprising a perforated sheet or an aluminum mesh and a first adhesive filled in the through holes) is cut out from the adhesive sheet, and the cut second layer is cut into an 8-inch silicon wafer. And imidized in a nitrogen atmosphere at 300 ° C. for 1.5 hours to obtain a second layer with a silicon wafer.
A second layer with a silicon wafer is processed to a width of 20 mm and a length of 100 mm, and a 90 ° peel evaluation is performed using a tensile tester (manufactured by Shimadzu Corporation, Autograph AGS-H) at a temperature of 23 ° C. and 300 mm / min. It was. The results are shown in Table 7.

[Process resistance evaluation]
Examples 1 to 3
The surfaces on which the first adhesive layer and the second layer of the adhesive sheets of Examples 1 to 3 were exposed were attached to a pedestal (a silicon wafer having a diameter of 200 mm and a thickness of 726 μm). The pasting was performed by roll lamination at a temperature of 90 ° C. and a pressure of 0.1 MPa.
Next, the adhesive sheet surface of the adhesive sheet with a pedestal was attached to the circuit forming surface of a silicon wafer having a diameter of 200 mm and a thickness of 725 μm. Pasting was performed at a temperature of 90 ° C. and a pressure of 0.1 MPa. After pasting, the adhesive sheet was imidized in a nitrogen atmosphere at 300 ° C. for 1.5 hours. As a result, a laminated body in which the pedestal, the adhesive sheet, and the silicon wafer were sequentially laminated was obtained.
Backgrinding was performed using the obtained laminate, and the case where the silicon wafer could be sufficiently fixed in the backgrind and satisfactorily background could be obtained. As evaluated.
Comparative Example 1
A laminate was obtained by the same method as in Examples 1 to 3, and the process resistance was evaluated.
The results are shown in Table 7.

[Peelability evaluation]
A laminated body in which a pedestal, an adhesive sheet, and a silicon wafer were sequentially laminated was obtained by the same method as in the process resistance evaluation.
Using a Thomson blade, a cut was made inward from the side surface of the adhesive sheet layer. The cut was made until the second layer was reached. After cutting, the silicon wafer was adsorbed upward using vacuum tweezers arranged on the upper side (silicon wafer side) of the laminate. The case where it was able to adsorb | suck was evaluated as (circle) and the case where it was not able to adsorb was evaluated as x. The results are shown in Table 7.

Claims

An adhesive sheet for manufacturing a semiconductor device used for fixing a semiconductor wafer to a pedestal,
A first adhesive layer and a second layer having an adhesive strength lower than that of the first adhesive layer;
An adhesive sheet for manufacturing a semiconductor device, wherein at least a peripheral portion of the adhesive sheet for manufacturing a semiconductor device is formed by the first adhesive layer.
2. The adhesive sheet for manufacturing a semiconductor device according to claim 1, wherein a central part inside the peripheral part is formed by stacking the first adhesive layer and the second layer.
2. The adhesive sheet for manufacturing a semiconductor device according to claim 1, wherein a central portion inside the peripheral portion is formed by the second layer.
The semiconductor device manufacturing according to any one of claims 1 to 3, wherein a third layer having an adhesive force lower than that of the first adhesive layer is formed over the peripheral portion and the central portion. Adhesive sheet.
A semiconductor device obtained by using the adhesive sheet for manufacturing a semiconductor device according to any one of claims 1 to 4.
Fixing the semiconductor wafer to the pedestal using the adhesive sheet for manufacturing a semiconductor device according to any one of claims 1 to 4,
And a step of separating the pedestal from the semiconductor wafer.