Semiconductor device manufacturing method

Abstract

The manufacturing method includes the following steps: for example, a step of forming a semiconductor wafer divided body (10) including a plurality of semiconductor chips (11) from a semiconductor wafer (W) on a dicing tape (T1); a step of attaching a sintering bonding sheet (20) to the semiconductor wafer divided body (10) on the dicing tape (T1); for example, a step of picking up a semiconductor chip (11) with a sintering bonding material layer (21) from the sintering bonding sheet (20) from the dicing tape (T1); a step of temporarily fixing the semiconductor chip (11) with the sintering bonding material layer to a substrate by means of the sintering bonding material layer (21); and a step of forming a sintered layer by heating the sintering bonding material layer (21) sandwiched between the temporarily fixed semiconductor chip (11) and the substrate, and bonding the semiconductor chip (11) to the substrate. This semiconductor device manufacturing method is suitable for efficiently supplying sintering bonding material to each semiconductor chip while reducing the loss of sintering bonding material.

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a semiconductor device, such as a so-called power semiconductor device. Background Art

[0002] In the manufacture of semiconductor devices, the following methods are known as methods for electrically connecting a semiconductor chip to a supporting substrate such as a lead frame or an insulating circuit substrate while bonding the chip to the supporting substrate: a method of forming an Au-Si eutectic alloy layer between the supporting substrate and the chip to achieve a bonding state; and a method of using solder or a resin containing conductive particles as bonding materials.

[0003] On the other hand, in recent years, the popularity of power semiconductor devices that are responsible for controlling the supply of electricity has increased significantly. In power semiconductor devices, in most cases, a large amount of heat is released due to the large amount of current flowing during operation. Therefore, in the manufacture of power semiconductor devices, a method of bonding the chip to the support substrate while allowing the semiconductor chip to be electrically connected to the support substrate side is required to achieve a highly reliable bonding state even during high-temperature operation. Such a requirement is particularly strong in power semiconductor devices that use SiC and GaN as semiconductor materials to achieve high-temperature operation. In addition, in order to meet such requirements, a technology using a sintering bonding composition containing sinterable particles and a solvent has been proposed as a chip bonding method accompanied by electrical connection.

[0004] In chip bonding using a sintering bonding material containing sinterable particles, first, a semiconductor chip is placed under specified temperature / load conditions relative to a predetermined chip bonding position of a support substrate with the aid of the sintering bonding material. Afterwards, a heating process is performed under specified temperature / pressure conditions in a manner such that the solvent in the sintering bonding material evaporates between the support substrate and the semiconductor chip thereon and sintering is performed between the sinterable particles. Thus, a sintering layer is formed between the support substrate and the semiconductor chip, the semiconductor chip is electrically connected to the support substrate, and the bonding is performed mechanically. Such a technology is described in, for example, the following patent documents 1 and 2.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: International Publication No. 2008 / 065728

[0008] Patent Document 2: Japanese Patent Application Publication No. 2013-039580 Summary of the invention

[0009] Problem that the invention aims to solve

[0010] In the manufacturing process of semiconductor devices that perform chip bonding by sintering bonding, in order to supply sintering bonding materials to multiple semiconductor chips at a time, a process such as the following has been proposed. First, multiple semiconductor chips are arranged on a processing tape having an adhesive surface on one side and / or its adhesive surface. Next, relative to the semiconductor chip array on the processing tape, a sheet body with a sintering bonding material layer is pressed on the surface of a plastic film while the material layer of the sheet body is pasted. Next, the portion of the sintering bonding material layer to be pressed onto the semiconductor chip remains on the semiconductor chip, and the sheet body is peeled off at the same time. By pasting and then peeling off the sheet body, the sintering bonding material is transferred from the sheet body to each semiconductor chip. According to this method, sintering bonding materials can be supplied to multiple semiconductor chips at a time. However, in this method, the loss of sintering bonding materials is relatively large. The reason is as follows.

[0011] In order to avoid contact between chips that may cause chip defects during the arrangement operation, for example, the semiconductor chips are arranged on the processing tape while fully ensuring the spacing distance between adjacent chips. The spacing distance is about 800 to 2000 μm. That is, there are obvious gaps between the semiconductor chips in the semiconductor chip array on the processing tape after the arrangement operation. Therefore, in the above-mentioned sheet body for supplying sintering bonding material, each part of the sintering bonding material layer (a part of the sintering bonding material layer) that is pressed against each semiconductor chip when pasted to the semiconductor chip array will be transferred to the semiconductor chip. The part of the sintering bonding material layer that is located in the gap between the semiconductor chips during pasting will not be transferred to the semiconductor chip. The part of the sintering bonding material layer that is not transferred to the semiconductor chip will become a loss. There is a tendency that the larger the gap between the semiconductor chips arranged on the processing tape, the greater the loss.

[0012] The present invention has been conceived based on the above circumstances, and an object of the present invention is to provide a method for manufacturing a semiconductor device having a sinter-bonding portion for semiconductor chips suitable for efficiently supplying sinter-bonding materials to each semiconductor chip while reducing the loss of sinter-bonding materials.

[0013] Solutions for solving problems

[0014] The semiconductor device manufacturing method provided by the first aspect of the present invention includes at least the following steps of dividing, pasting, picking up, temporarily fixing and sintering. This method is suitable for manufacturing semiconductor devices such as power semiconductor devices having sintered bonding parts of semiconductor chips.

[0015] In the segmentation process, a semiconductor wafer segment including a plurality of semiconductor chips is formed from a semiconductor wafer in a state of being held on a dicing tape. In this process, a semiconductor wafer segment can be formed by cutting the semiconductor wafer with a blade (first method). Alternatively, in this process, after performing laser stealth dicing on a semiconductor wafer in a state of being held on a dicing tape, the dicing tape holding the semiconductor wafer is temporarily expanded, and the semiconductor wafer can be cut to form a semiconductor wafer segment (second method). In laser stealth dicing, a fragile area for cutting into a plurality of semiconductor chips is formed in the semiconductor wafer. The semiconductor wafer that has undergone laser stealth dicing is in a state where it can be cut along the fragile area by maintaining the expansion of the dicing tape. The distance between semiconductor chips of the semiconductor wafer segment formed by these first and second methods is about 10 to 500 μm.

[0016] In the pasting step, a sintering bonding sheet containing a binder component and sinterable particles containing a conductive metal is pasted to the semiconductor wafer divisions on the dicing tape from the side opposite to the dicing tape. Thus, the sintering bonding material from the sintering bonding sheet is pressed against each of the semiconductor chips to transfer the sintering bonding material layer.

[0017] In the picking-up process, the semiconductor chip and the sintering bonding material layer closely attached thereto are picked up together to obtain a semiconductor chip with a sintering bonding material layer. In the picking-up process, for example, the semiconductor chip with a sintering bonding material layer is picked up from a dicing tape. Alternatively, in the case where a wafer processing tape is pasted to the sintering bonding sheet side of a semiconductor wafer segment with a sintering bonding sheet between the pasting process and the picking-up process, and the dicing tape is peeled off from the semiconductor wafer segment, in the picking-up process, the semiconductor chip with a sintering bonding material layer is picked up from the wafer processing tape.

[0018] In the temporary fixing step, the semiconductor chip with the sinter bonding material layer is pressed and bonded to the substrate via the sinter bonding material layer, thereby being temporarily fixed.

[0019] In the sinter bonding step, the sinter bonding material layer interposed between the temporarily fixed semiconductor chip and the substrate is subjected to a heating process to form a sintered layer, and the semiconductor chip is sinter-bonded to the substrate.

[0020] In the present semiconductor device manufacturing method, in the pasting step, as described above, a sintering bonding sheet for supplying sintering bonding material is pasted to the semiconductor wafer segment (including a plurality of semiconductor chips that have been singulated) on the dicing tape. This configuration is suitable for efficiently supplying sintering bonding material to each of the plurality of semiconductor chips at once, that is, transferring and forming a sintering bonding material layer for each of the plurality of semiconductor chips.

[0021] Furthermore, in the present semiconductor device manufacturing method, the distance between chips of the semiconductor wafer segmented bodies (i.e., semiconductor wafers obtained by singulation into chips while being maintained on the dicing tape) formed by the segmentation process on the dicing tape is as short as about 10 to 500 μm as described above. In the pasting process, a sintering bonding sheet is pasted to the semiconductor wafer segmented bodies (the sintering bonding sheet is not pasted to a plurality of semiconductor chips arranged on a processing tape after the semiconductor wafer is singulated and with large gaps between the chips). Therefore, the present semiconductor device manufacturing method is suitable for reducing the loss of sintering bonding materials when the sintering bonding materials are supplied to each of a plurality of semiconductor chips at the same time.

[0022] As described above, the semiconductor device manufacturing method according to the first aspect of the present invention is suitable for efficiently supplying the sinter bonding material to each semiconductor chip while reducing the loss of the sinter bonding material.

[0023] The method preferably further includes a step of temporarily expanding a dicing tape holding the divided semiconductor wafer between the dividing step and the pasting step. This configuration is preferred for appropriately picking up each semiconductor chip in the picking up step.

[0024] The method preferably further includes an expansion step of temporarily expanding the dicing tape holding the semiconductor wafer segment between the pasting step and the picking-up step. This configuration is preferred for cutting the sintering bonding sheet before the picking-up step and properly picking up each semiconductor chip in the picking-up step. In addition, in the case of a process of pasting a wafer processing tape on the sintering bonding material layer side in a semiconductor wafer segment including a plurality of semiconductor chips closely attached to the sintering bonding material layer derived from the sintering bonding sheet between the expansion step and the picking-up step, and peeling the dicing tape from the semiconductor wafer segment, in the picking-up step, the semiconductor chip with the sintering bonding material layer is picked up from the wafer processing tape.

[0025] The semiconductor device manufacturing method provided by the second aspect of the present invention includes the following laser stealth cutting process, pasting process, cutting process, picking up process, temporary fixing process and sintering bonding process. In the laser stealth cutting process, a fragile area for cutting into multiple semiconductor chips is formed in the semiconductor wafer in a state of being held on the dicing tape. In the pasting process, a sintering bonding sheet containing an adhesive component and sintering particles containing a conductive metal is pasted from the side opposite to the dicing tape relative to the semiconductor wafer on the dicing tape. In the cutting process, the dicing tape holding the semiconductor wafer is expanded, so that the semiconductor wafer and the sintering bonding sheet are cut together to form a semiconductor wafer segment including multiple semiconductor chips that are tightly attached to the sintering bonding material layer derived from the sintering bonding sheet. In the picking up process, the semiconductor chip with the sintering bonding material layer is picked up from the dicing tape. Alternatively, between the above-mentioned cutting step and the picking-up step, a step of attaching a wafer processing tape to the sintering bonding material layer side of a semiconductor wafer segment including a plurality of semiconductor chips that are closely attached to a sintering bonding material layer derived from a sintering bonding sheet, and peeling off the dicing tape from the semiconductor wafer segment is performed, and in the picking-up step, the semiconductor chip with the sintering bonding material layer is picked up from the wafer processing tape. In the temporary fixing step, the semiconductor chip with the sintering bonding material layer is temporarily fixed to the substrate with the aid of its sintering bonding material layer. In the sintering bonding step, the sintering bonding material layer sandwiched between the temporarily fixed semiconductor chip and the substrate undergoes a heating process to form a sintered layer, and the semiconductor chip is sinter-bonded to the substrate.

[0026] In the semiconductor device manufacturing method described in the second aspect of the present invention, in the pasting step, as described above, a sintering bonding sheet for supplying sintering bonding material is pasted to the semiconductor wafer after laser stealth dicing on the dicing tape. This structure is suitable for efficiently supplying sintering bonding material to each portion of the semiconductor wafer to be singulated into semiconductor chips at a time, that is, transferring and forming a sintering bonding material layer to each portion of the semiconductor wafer to be singulated into semiconductor chips.

[0027] Furthermore, in the pasting process of the semiconductor device manufacturing method described in the second aspect of the present invention, a sintering bonding sheet is pasted to a semiconductor wafer that has not been singulated into chips (i.e., a semiconductor wafer without gaps between chips). In this pasting process, the sintering bonding sheet for supplying the sintering bonding material can be pressed against the entire surface of the semiconductor wafer in the area where it is pasted to the semiconductor wafer. Therefore, the present semiconductor device manufacturing method is suitable for reducing the loss of the sintering bonding material supplied to the multiple semiconductor chips obtained in the process.

[0028] As described above, the semiconductor device manufacturing method according to the second aspect of the present invention is suitable for efficiently supplying the sinter bonding material to each semiconductor chip while reducing the loss of the sinter bonding material.

[0029] The semiconductor device manufacturing method provided by the third aspect of the present invention includes the following pasting process, singulation process, picking-up process, temporary fixing process and sintering and bonding process. In the pasting process, a sintering and bonding sheet is pasted from the side opposite to the dicing tape relative to the semiconductor wafer held on the dicing tape. The sintering and bonding sheet contains a binder component and sinterable particles containing a conductive metal. In the singulation process, the semiconductor wafer on the dicing tape is singulated together with the sintering and bonding sheet to form a semiconductor wafer segment containing a plurality of semiconductor chips that are closely attached to the sintering and bonding material layer derived from the sintering and bonding sheet. In the singulation process, the semiconductor wafer segment can be formed by blade cutting the semiconductor wafer and the sintering and bonding sheet thereon. Alternatively, in the singulation process, after a fragile region for cutting into a plurality of semiconductor chips is formed in the semiconductor wafer held on the dicing tape, the semiconductor wafer and the sintering and bonding sheet thereon can be cut by expanding the dicing tape that holds the semiconductor wafer to form a semiconductor wafer segment. In the picking process, the semiconductor chip and the sintering bonding material layer closely attached thereto are picked up together to obtain a semiconductor chip with a sintering bonding material layer. In the picking process, the semiconductor chip with the sintering bonding material layer is picked up from the dicing tape. Alternatively, between the above-mentioned singulation process and the picking process, a wafer processing tape is attached to the sintering bonding material layer side of the semiconductor wafer segment including a plurality of semiconductor chips closely attached to the sintering bonding material layer derived from the sintering bonding sheet, and the dicing tape is peeled off from the semiconductor wafer segment. In the picking process, the semiconductor chip with the sintering bonding material layer is picked up from the wafer processing tape. In the temporary fixing process, the semiconductor chip with the sintering bonding material layer is temporarily fixed to the substrate with the aid of its sintering bonding material layer. In the sintering bonding process, the sintering bonding material layer sandwiched between the temporarily fixed semiconductor chip and the substrate undergoes a heating process to form a sintered layer, and the semiconductor chip is sintered and bonded to the substrate.

[0030] In the semiconductor device manufacturing method described in the third aspect of the present invention, in the pasting step, as described above, a sintering bonding sheet for supplying a sintering bonding material is pasted to the semiconductor wafer on the dicing tape. This configuration is suitable for efficiently supplying a sintering bonding material to each portion of the semiconductor wafer to be singulated into semiconductor chips at once, that is, transferring and forming a sintering bonding material layer to each portion of the semiconductor wafer to be singulated into semiconductor chips.

[0031] Furthermore, in the pasting process of the semiconductor device manufacturing method described in the third aspect of the present invention, a sintering bonding sheet is pasted to a semiconductor wafer that has not been singulated into chips (i.e., a semiconductor wafer without gaps between chips). In this pasting process, the sintering bonding sheet for supplying the sintering bonding material can be pressed against the entire surface of the semiconductor wafer in the area where it is pasted to the semiconductor wafer. Therefore, the semiconductor device manufacturing method is suitable for reducing the loss of the sintering bonding material supplied to the multiple semiconductor chips obtained in the process.

[0032] As described above, the semiconductor device manufacturing method according to the third aspect of the present invention is suitable for efficiently supplying the sinter bonding material to each semiconductor chip while reducing the loss of the sinter bonding material.

[0033] In the first to third aspects of the present invention, the thickness of the sintered layer formed by the sintering bonding process is preferably in the range of 60 to 140% of the average thickness of the sintered layer, more preferably in the range of 80 to 120%, and more preferably in the range of 90 to 110%. The more uniform the thickness of the sintered layer, the easier it is to obtain high bonding reliability in the sintered layer. In addition, the average thickness of the sintered layer formed by the sintering bonding process is preferably 5 to 200 μm, more preferably 10 to 150 μm. This structure is preferred for alleviating the internal stress caused by thermal stress in the sintered layer and ensuring sufficient thermal shock reliability, while suppressing the cost associated with sintering bonding and thus the manufacturing cost of the semiconductor device.

[0034] The sinterable particles in the sintering bonding sheet used in the first to third aspects of the present invention preferably contain at least one selected from the group consisting of silver, copper, silver oxide and copper oxide. This structure is suitable for forming a strong sintered layer between the substrate to be sintered and the semiconductor chip. In addition, the binder component in the sintering bonding sheet is preferably a thermally decomposable polymer binder. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 A part of the steps in a method for manufacturing a semiconductor device according to one embodiment of the present invention is shown.

[0036] Figure 2 express Figure 1 The subsequent process of the indicated process.

[0037] Figure 3 express Figure 2 The subsequent process of the indicated process.

[0038] Figure 4 express Figure 3 The subsequent process of the indicated process.

[0039] Figure 5 A part of the steps in a method for manufacturing a semiconductor device according to one embodiment of the present invention is shown.

[0040] Figure 6 A part of the steps in a method for manufacturing a semiconductor device according to one embodiment of the present invention is shown.

[0041] Figure 7 A part of the steps in a method for manufacturing a semiconductor device according to one embodiment of the present invention is shown.

[0042] Figure 8 A part of the steps in a method for manufacturing a semiconductor device according to one embodiment of the present invention is shown.

[0043] Fig. 9 A part of the steps in a method for manufacturing a semiconductor device according to one embodiment of the present invention is shown.

[0044] Fig.10 express Fig. 9 The subsequent process of the indicated process.

[0045] Fig.11 A part of the steps in a method for manufacturing a semiconductor device according to one embodiment of the present invention is shown.

[0046] Fig.12 A part of the steps in a method for manufacturing a semiconductor device according to one embodiment of the present invention is shown.

[0047] Fig.13 A part of the steps in a method for manufacturing a semiconductor device according to one embodiment of the present invention is shown. DETAILED DESCRIPTION

[0048] Figure 1 to Figure 4 A semiconductor device manufacturing method according to an embodiment of the present invention is shown. The semiconductor device manufacturing method of this embodiment is a method for manufacturing a semiconductor device such as a power semiconductor device having a sintered bonding portion of a semiconductor chip, and includes the following steps of dividing, pasting, picking up, temporarily fixing, and sintering.

[0049] In the segmentation process, Figure 1 (a) and Figure 1 As shown in (b) of FIG. 8 , the semiconductor wafer W held on the dicing tape T1 is cut by a blade to form semiconductor wafer divided bodies 10 .

[0050] The dicing tape T1 has a laminated structure of, for example, a base material and an adhesive layer, and has an adhesive surface T1a formed by an adhesive layer on one side. The semiconductor wafer W has an element forming surface on one side where a semiconductor element is made and a back side opposite thereto. A planar electrode (not shown) serving as an external electrode is formed on the back side. As constituent materials for forming the wafer body of the semiconductor wafer W, semiconductor materials for power semiconductor devices such as silicon carbide (SiC) and gallium nitride (GaN) can be cited. The thickness of the semiconductor wafer W is, for example, 20 to 1000 μm.

[0051] Specifically, in this process, first, the adhesive surface T1a of the dicing tape T1 is attached to the element forming surface (lower surface in the figure) of the semiconductor wafer W. A ring frame R is attached to the peripheral portion of the adhesive surface T1a of the dicing tape T1. The ring frame R is a member that a transport mechanism such as a transport arm of a dicing device (not shown) mechanically abuts when transporting a workpiece in a state of being attached to the dicing tape T1.

[0052] In this process, while the semiconductor wafer W is held on the adhesive surface T1a of the dicing tape T1, a rotating blade (not shown) provided by the dicing device is driven to perform cutting processing on the semiconductor wafer W. The cutting processing is performed along the predetermined cutting line while water is continuously supplied to the rotating blade and the semiconductor wafer W. Figure 1 In (b), the cutting groove G formed by the rotary blade for cutting is schematically indicated by a thick line. The cutting depth of the cutting groove G can reach the inside of the dicing tape T1. By undergoing this dividing process, the semiconductor wafer W is singulated into chips on the dicing tape T1 to form a semiconductor wafer divided body 10 including a plurality of semiconductor chips 11. The distance between the semiconductor chips 11 of the semiconductor wafer divided body 10 formed by this operation is, for example, 10 to 500 μm.

[0053] In this embodiment, then Figure 1 As shown in (c), a sintering bonding sheet 20 is pasted to the semiconductor wafer split body 10 (pasting process). The sintering bonding sheet 20 is a sheet of a composition containing at least a binder component and sinterable particles containing a conductive metal, and is pasted to the semiconductor wafer split body 10 and / or its back side on the dicing tape T1 from the side opposite to the dicing tape T1. As a pressing means for pasting, for example, a pressure roller can be cited. The pasting temperature is, for example, in the range of room temperature to 200°C, and the load for pasting is, for example, 0.01 to 10 MPa. In this process, the sintering bonding material derived from the sintering bonding sheet 20 can be pressed against each of the semiconductor chips 11 in the semiconductor wafer split body 10, and the sintering bonding material layer 21 can be transferred at the same time.

[0054] The sinter-bonding sheet 20 is a sheet used for sinter-bonding objects to be bonded, and is a sheet body including a composition of at least a binder component and sinterable particles containing a conductive metal, as described above.

[0055] The sinterable particles in the sintering bonding sheet 20 are particles containing conductive metal elements and capable of sintering. As conductive metal elements, for example, gold, silver, copper, palladium, tin and nickel can be cited. As the constituent materials of such sinterable particles, for example, gold, silver, copper, palladium, tin, nickel and alloys of two or more metals selected from their groups can be cited. As the constituent materials of sinterable particles, metal oxides such as silver oxide, copper oxide, palladium oxide, and tin oxide can also be cited. In addition, the sinterable particles can be particles with a core-shell structure. For example, the sinterable particles can be particles of the following core-shell structure, that is, the particles of the core-shell structure have a core with copper as the main component and a shell with gold, silver, etc. as the main component and covering the core. In the present embodiment, the sinterable particles preferably include at least one selected from the group consisting of silver particles, copper particles, silver oxide particles and copper oxide particles. From the viewpoint that the formed sintered layer realizes high electrical conductivity and high thermal conductivity, as sinterable particles, silver particles and copper particles are preferably used. And, from the viewpoint of oxidation resistance, silver particles are easy to handle and are preferred. For example, in the sintering bonding of a semiconductor chip to a copper substrate with a silver plated layer, when a sintering material containing copper particles as sinterable particles is used, the sintering process needs to be performed in an inactive environment such as a nitrogen atmosphere. However, when a sintering material containing silver particles as sinterable particles is used, the sintering process can be properly performed even in an air atmosphere.

[0056] From the viewpoint of achieving a low sintering temperature for the sinterable particles and ensuring good sinterability, the average particle size of the sinterable particles used is preferably 2000nm or less, more preferably 800nm ​​or less, and more preferably 500nm or less. From the viewpoint of achieving good dispersibility for the sinterable particles in the sintering bonding sheet 20 and / or the composition used to form it, the average particle size of the sinterable particles is preferably 1nm or more, more preferably 10nm or more, more preferably 50nm or more, and more preferably 100nm or more. The average particle size of the sinterable particles can be measured by observation using a scanning electron microscope (SEM).

[0057] From the viewpoint of achieving highly reliable sintered bonding, the content of the sinterable particles in the sintered bonding sheet 20 is preferably 60 to 99 mass %, more preferably 65 to 98 mass %, more preferably 70 to 97 mass %, and even more preferably 70 to 95 mass %.

[0058] In the present embodiment, the binder component in the sintering bonding sheet 20 includes at least a thermally decomposable polymer binder and a low boiling point binder, and may further include other components such as a plasticizer. The thermally decomposable polymer binder is a binder component that can be thermally decomposed during the high-temperature heating process for sintering bonding, and is an element that helps to maintain the sheet shape of the sintering bonding sheet 20 until the heating process. In the present embodiment, from the perspective of guaranteeing the sheet shape retention function, the thermally decomposable polymer binder is a material that is solid at room temperature (23°C). Examples of such thermally decomposable polymer binders include polycarbonate resins and acrylic resins.

[0059] Examples of polycarbonate resins that are thermally decomposable polymer binders include: aliphatic polycarbonates that do not contain aromatic compounds such as benzene rings between the carbonate groups (-O-CO-O-) of the main chain and contain aliphatic chains; and aromatic polycarbonates that contain aromatic compounds between the carbonate groups (-O-CO-O-) of the main chain. Examples of aliphatic polycarbonates include polyethylene carbonate and polypropylene carbonate. Examples of aromatic polycarbonates include polycarbonates that contain a bisphenol A structure in the main chain.

[0060] Examples of acrylic resins that are heat-decomposable polymer binders include polymers of acrylic acid esters and / or methacrylic acid esters having a linear or branched alkyl group with 4 to 18 carbon atoms. In the following, "(meth)acrylic acid" means "acrylic acid" and / or "methacrylic acid", and "(meth)acrylate" means "acrylate" and / or "methacrylate". Examples of the alkyl group of (meth)acrylate used to form the acrylic resin that is a heat-decomposable polymer binder include methyl, ethyl, propyl, isopropyl, n-butyl, tert-butyl, isobutyl, amyl, isopentyl, hexyl, heptyl, cyclohexyl, 2-ethylhexyl, octyl, isooctyl, nonyl, isononyl, decyl, isodecyl, undecyl, lauryl, tridecyl, tetradecyl, stearyl, and octadecyl.

[0061] The acrylic resin of the thermally decomposable polymer binder can be a polymer containing monomer units derived from other monomers other than the above-mentioned (meth) acrylic acid ester. As such other monomers, for example, carboxyl-containing monomers, anhydride monomers, hydroxyl-containing monomers, sulfonic acid-containing monomers, and phosphoric acid-containing monomers can be cited. Specifically, as carboxyl-containing monomers, for example, acrylic acid, methacrylic acid, carboxyethyl acrylate, carboxypentyl acrylate, itaconic acid, maleic acid, fumaric acid, and crotonic acid can be cited. As anhydride monomers, for example, maleic anhydride and itaconic anhydride can be cited. As hydroxyl-containing monomers, for example, 2-hydroxyethyl (meth) acrylic acid, 2-hydroxypropyl (meth) acrylic acid, 4-hydroxybutyl (meth) acrylic acid, 6-hydroxyhexyl (meth) acrylic acid, 8-hydroxyoctyl (meth) acrylic acid, 10-hydroxydecyl (meth) acrylic acid, 12-hydroxylauryl (meth) acrylic acid, and 4-(hydroxymethyl)cyclohexylmethyl (meth) acrylic acid can be cited. Examples of the sulfonic acid group-containing monomer include styrene sulfonic acid, allyl sulfonic acid, 2-(meth)acrylamide-2-methylpropanesulfonic acid, (meth)acrylamidepropanesulfonic acid, (meth)acrylate sulfopropyl ester, and (meth)acryloyloxynaphthalenesulfonic acid. Examples of the phosphoric acid group-containing monomer include 2-hydroxyethylacryloyl phosphate.

[0062] The weight average molecular weight of the thermally decomposable polymer binder is preferably not less than 10000. The weight average molecular weight of the thermally decomposable polymer binder is a value measured by gel permeation chromatography (GPC) and calculated in terms of polystyrene.

[0063] From the viewpoint of appropriately exhibiting the sheet shape-retaining function, the content of the thermally decomposable polymer binder in the sintered bonding sheet 20 is preferably 0.5 to 10% by mass, more preferably 0.8 to 8% by mass, and even more preferably 1 to 6% by mass.

[0064] The low boiling point binder in the sinter bonding sheet 20 has a viscosity of 1×10 5 Liquid or semi-liquid adhesive with a viscosity of less than Pa·s. In this viscosity measurement, parallel plates with a diameter of 20 mm were used as a jig, the gap between the plates was set to 100 μm, and the shear rate in the rotational shear was set to 1 s. -1 .

[0065] As the above-mentioned low boiling point binder, for example, terpene alcohols, alcohols other than terpene alcohols, alkylene glycol alkyl ethers, and ethers other than alkylene glycol alkyl ethers can be cited. As terpene alcohols, for example, isobornyl cyclohexanol, citronellol, geraniol, nerol, carveol, and α-terpineol can be cited. As alcohols other than terpene alcohols, for example, amyl alcohol, hexanol, heptanol, octanol, 1-decanol, ethylene glycol, diethylene glycol, propylene glycol, butanediol, and 2,4-diethyl-1,5-pentanediol can be cited. Examples of the alkylene glycol alkyl ethers include ethylene glycol butyl ether, diethylene glycol methyl ether, diethylene glycol ethyl ether, diethylene glycol butyl ether, diethylene glycol isobutyl ether, diethylene glycol hexyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, diethylene glycol butyl methyl ether, diethylene glycol isopropyl methyl ether, triethylene glycol methyl ether, triethylene glycol dimethyl ether, triethylene glycol butyl methyl ether, propylene glycol propyl ether, dipropylene glycol methyl ether, dipropylene glycol ethyl ether, dipropylene glycol propyl ether, dipropylene glycol butyl ether, dipropylene glycol dimethyl ether, tripropylene glycol methyl ether, and tripropylene glycol dimethyl ether. As ethers other than alkylene glycol alkyl ethers, for example, ethylene glycol ethyl ether acetate, ethylene glycol butyl ether acetate, diethylene glycol ethyl ether acetate, diethylene glycol butyl ether acetate, and dipropylene glycol methyl ether acetate can be cited. As a component in the sintering bonding sheet 20, one low boiling point binder can be used, or two or more low boiling point binders can be used. As the low boiling point binder in the sintering bonding sheet 20, from the viewpoint of stability at room temperature, terpene alcohols are preferred, and isobornyl cyclohexanol is more preferred.

[0066] The thickness of the sintered bonding sheet 20 at 23°C is preferably 5 μm or more, more preferably 10 μm or more, and preferably 300 μm or less, more preferably 150 μm or less. The viscosity of the sintered bonding sheet 20 and / or the sintered bonding composition forming the sintered bonding sheet 20 at 70°C is, for example, 5×10 3 ~1×10 7 Pa·s, preferably 1×10 4 ~1×10 6 Pa·s.

[0067] The sintered bonding sheet 20 can be produced, for example, by mixing the above components in a solvent to prepare a varnish, applying the varnish on a separator as a substrate to form a coating film, and drying the coating film. As the solvent for preparing the varnish, an organic solvent or an alcohol solvent can be used.

[0068] In this embodiment, after the pasting process, Figure 1The inversion step as shown in (d) is performed. Specifically, in this step, a wafer processing tape T2 having an adhesive surface T2a is adhered to the semiconductor wafer segment 10 with the sintering bonding sheet 20, that is, the workpiece, and the dicing tape T1 is peeled off from the workpiece. The adhesive force of the adhesive surface T2a of the processing tape T2 is equal to or greater than the adhesive force of the adhesive surface T1a of the processing tape T1. In this step, for example, on one side of the sintering bonding sheet 20 in the semiconductor wafer segment 10 with the sintering bonding sheet 20, the wafer processing tape T2 is adhered with its adhesive surface T2a side, and then the dicing tape T1 is peeled off from the semiconductor wafer segment 10.

[0069] In the semiconductor device manufacturing method, next, Figure 2 As shown in the figure, the semiconductor chip 11 and the sintering bonding material layer 21 closely attached thereto are picked up from the wafer processing tape T2 together to obtain the semiconductor chip 11 with the sintering bonding material layer (pick-up process). In this process, specifically, for the semiconductor chip 11 with the sintering bonding material layer as the pickup object, the pin member 33 of the pickup mechanism is raised on the lower side of the wafer processing tape T2 in the figure and lifted up through the wafer processing tape T2, and then the semiconductor chip 11 is sucked and held by the suction collet C. The suction holding effect of the suction collet C can be used to pick up the semiconductor chip 11 with the sintering bonding material layer. The same is true in the pickup process described later.

[0070] Then, if Figure 3 As shown in (a), the semiconductor chip 11 with a sintered bonding material layer is temporarily fixed by pressing the sintered bonding material layer 21 onto the supporting substrate S (temporary fixing process). Specifically, for example, a chip mounter is used to temporarily fix the semiconductor chip 11 with a sintered bonding material layer onto the supporting substrate S by pressing the sintered bonding material layer 21 onto the supporting substrate S. As the supporting substrate S, for example, lead frames and insulating circuit substrates with wiring such as copper wiring on the surface can be cited. The chip mounting portion in the supporting substrate S can be a substrate surface of copper wiring, lead frames, etc., or a plated surface formed on the substrate surface. As the plating, for example, gold plating, silver plating, nickel plating, palladium plating and platinum plating can be cited. In this process, the temperature conditions for temporary fixing are, for example, in the range of room temperature to 300°C, the pressing load is, for example, 0.01 to 50 MPa, and the bonding time is, for example, 0.01 to 300 seconds.

[0071] Then, if Figure 3As shown in (b), a sintering layer 22 is formed by a sintering bonding material layer 21 sandwiched between a temporarily fixed semiconductor chip 11 and a substrate S, and the semiconductor chip 11 is sintered and bonded to the supporting substrate S (sintering bonding process). Specifically, by undergoing a predetermined high-temperature heating process, the low-boiling point binder in the sintering bonding material layer 21 is volatilized, the thermally decomposable polymer binder is thermally decomposed and volatilized, and the conductive metal of the sinterable particles is sintered. Thus, a sintering layer 22 is formed between the supporting substrate S and each semiconductor chip 11, and the semiconductor chip 11 is bonded to the supporting substrate S while being electrically connected to the supporting substrate S side. In this process, the temperature conditions for sintering bonding are, for example, in the range of 150 to 400°C, and preferably in the range of 250 to 350°C. The pressure used for sintering bonding is, for example, below 60 MPa, and preferably below 40 MPa. In addition, the bonding time of the sintering bond is, for example, 0.3 to 300 minutes, preferably 0.5 to 240 minutes. For example, within the range of these conditions, the temperature curve and pressure curve for implementing the sintering bond process are appropriately set. The sintering bond process as above can be carried out using a device that can heat and pressurize at the same time. As such a device, for example, a flip chip bonding machine and a parallel plate press can be cited. In addition, from the viewpoint of preventing oxidation of the metal involved in the sintering bond, this process is preferably carried out under a nitrogen atmosphere, under reduced pressure or under a reducing gas atmosphere.

[0072] In the present embodiment, the thickness of the sintered layer 22 formed by the sintering bonding process is preferably in the range of 60 to 140% of the average thickness of the sintered layer 22, more preferably in the range of 80 to 120%, and more preferably in the range of 90 to 110%. The more uniform the thickness of the sintered layer 22 is, the easier it is to obtain high bonding reliability in the sintered layer 22. In addition, the average thickness of the sintered layer 22 is preferably 5 to 200 μm, more preferably 10 to 150 μm. This configuration is preferred for alleviating the internal stress caused by thermal stress in the sintered layer 22 and ensuring sufficient thermal shock reliability while suppressing the cost associated with sintering bonding and, in turn, the manufacturing cost of the semiconductor device.

[0073] In the semiconductor device manufacturing method, next, Figure 4As shown in (a), the terminal portion (not shown) of the semiconductor chip 11 and the terminal portion (not shown) of the supporting substrate S are electrically connected by means of a bonding wire W as needed (wire bonding process). The connection between the terminal portion of the semiconductor chip 11, the terminal portion of the supporting substrate S and the bonding wire W is achieved by, for example, ultrasonic welding accompanied by heating. As the bonding wire W, for example, a gold wire, an aluminum wire or a copper wire can be used. The wire heating temperature in wire bonding is, for example, 80 to 250°C, preferably 80 to 220°C. In addition, the heating time is several seconds to several minutes.

[0074] Then, if Figure 4 As shown in (b), a sealing resin M for protecting the semiconductor chip 11 and the bonding lead W on the supporting substrate S is formed (sealing process). In this process, the sealing resin M is formed, for example, by a transfer molding technique using a mold. As a constituent material of the sealing resin M, for example, an epoxy resin can be used. In this process, the heating temperature for forming the sealing resin M is, for example, 165 to 185°C, and the heating time is, for example, 60 seconds to several minutes. In the case where the sealing resin M is not fully cured in this sealing process, a post-curing process for completely curing the sealing resin M is performed after this process.

[0075] As described above, a semiconductor device including a sintered bonded portion of a semiconductor chip can be manufactured.

[0076] In the semiconductor device manufacturing method, the following pick-up process and the subsequent inversion process may be performed instead of referring to Figure 1 (d) The inversion process described above and the reference Figure 2 The picking process described above.

[0077] In reference Figure 1 (c) After the above-mentioned pasting step is performed, that is, the sintering bonding sheet 20 is pasted to the semiconductor wafer divided body 10 on the dicing tape T1, as shown in FIG. Figure 5 As shown in (a), the semiconductor chip 11 and the sintering bonding material layer 21 closely attached thereto are picked up from the dicing tape T1 together to obtain the semiconductor chip 11 with the sintering bonding material layer (picking up process). In this picking up process, the suction barrel clamp C used holds the semiconductor chip 11 by sucking the semiconductor chip 11 with the sintering bonding material layer toward the sintering bonding material layer 21 side. Next, as Figure 5As shown in (b), the semiconductor chip 11 is transferred from the suction clamp C that has picked up the semiconductor chip 11 with the sintering bonding material layer to the other suction clamp C' (reversal process). The suction clamp C' holds the semiconductor chip 11 by sucking the semiconductor chip 11 with the sintering bonding material layer toward the chip side. The semiconductor chip 11 with the sintering bonding material layer is supplied to the reference Figure 3 (a) is the temporary fixing process described above.

[0078] In the semiconductor device manufacturing method, referring to Figure 1 (a) and Figure 1 (b) The segmentation process described above and the reference Figure 1 (c) between the pasting steps described above, such as Figure 6 As shown, a step of temporarily expanding the dicing tape T1 holding the divided semiconductor wafer body 10 may be performed.

[0079] In this expansion process, the expansion device is used, first Figure 6 As shown in (a) of FIG. 1 , the dicing tape T1 with the semiconductor wafer divided body 10 and the ring frame R on the adhesive surface T1a is fixed to the holding tool 31 of the expansion device. Figure 6 As shown in (b), the hollow cylindrical lifting member 32 of the expansion device abuts against the dicing tape T1 from the lower side thereof and rises, and the dicing tape T1 to which the semiconductor wafer segment 10 is attached is expanded in a manner of being stretched in two-dimensional directions including the radial direction and the circumferential direction of the semiconductor wafer segment 10. The temperature condition during expansion is, for example, -20 to 70°C. Thereafter, as Figure 6 As shown in (c), the lifting member 32 is lowered, and the expanded state of the dicing tape T1 is released. After expansion, the portion of the dicing tape T1 that is closer to the outside than the semiconductor wafer segment holding area can be heated to shrink. The heating temperature is, for example, 100 to 300° C. This structure is preferred for suppressing the narrowing of the spacing distance between the semiconductor chips 11 after expansion.

[0080] In the semiconductor device manufacturing method of the present invention, Figure 1 (c) The pasting process described above and the reference Figure 1 (d) is performed between the reversal steps described above. Figure 7 In addition, after going through the reference Figure 5 In the case of the process described above, Figure 1 (c) The pasting process described above and the reference Figure 5 (a) is performed between the picking steps described above. Figure 7The expansion process as shown.

[0081] In this expansion process, the expansion device is used, first Figure 7 As shown in (a) of FIG. 1 , the dicing tape T1 having the semiconductor wafer divided body 10 with the sintered bonding sheet 20 and the ring frame R on the bonding surface T1a is fixed to the holding tool 31 of the expansion device. Figure 7 As shown in (b), the hollow cylindrical lifting member 32 of the expansion device abuts against the dicing tape T1 from the lower side thereof and rises, and the dicing tape T1 to which the semiconductor wafer segment 10 is attached is expanded in a manner of being stretched in two-dimensional directions including the radial direction and the circumferential direction of the semiconductor wafer segment 10. The temperature condition during expansion is, for example, -20 to 70°C. Thereafter, as Figure 7 As shown in (c), the lifting member 32 descends and the expanded state of the dicing tape T1 is released. After expansion, the portion of the dicing tape T1 that is closer to the outside than the semiconductor wafer segment holding area can be heated to shrink. The heating temperature is, for example, 100 to 300°C. This structure is preferred for suppressing the narrowing of the spacing distance between the semiconductor chips 11 after expansion. By going through the expansion process as described above, a sufficient spacing distance can be ensured between the semiconductor chips 11 that are to be picked up before the picking process, so the picking process can be properly performed.

[0082] In the semiconductor device manufacturing method, Figure 8 Instead of referring to the segmentation process shown in Figure 1 (a) and Figure 1 (b) The segmentation step described above.

[0083] In this segmentation process, first Figure 8 As shown in (a) of FIG. 1 , the semiconductor wafer W held on the dicing tape T1 is subjected to invisible laser dicing, and a fragile region F for dicing into a plurality of semiconductor chips is formed in the semiconductor wafer W.

[0084] In the laser stealth dicing, for example, the semiconductor wafer W is irradiated with laser light focused on the inside of the semiconductor wafer W along the predetermined dividing line from the side opposite to the dicing tape T1, and abrasion based on multiphoton absorption is used to form a fragile region F in the semiconductor wafer W. Regarding the method of forming the fragile region F on the predetermined dividing line in the semiconductor wafer by laser irradiation, as described in detail in, for example, Japanese Patent Application Laid-Open No. 2002-192370, the laser irradiation conditions in the present embodiment are appropriately adjusted within the range of, for example, the following conditions.

[0085] <Laser irradiation conditions>

[0086] (A) Laser

[0087]

[0088] (B) Focusing lens

[0089] Magnification less than 100 times

[0090] NA 0.55

[0091] Transmittance to laser wavelength 100% or less

[0092] (C) The moving speed of the stage on which the semiconductor substrate is placed is 280 mm / sec or less

[0093] Before or after such stealth laser dicing, the semiconductor wafer W can be thinned by grinding the back side thereof. The semiconductor wafer W subjected to stealth laser dicing is in a state where it can be cut along the fragile region F while maintaining the expansion of the dicing zone T1.

[0094] In this segmentation process, Figure 8 As shown in (b), the dicing tape T1 with the semiconductor wafer W and the ring frame R subjected to the laser stealth dicing on the adhesive surface T1a is fixed to the holding tool 31 of the expansion device. Figure 8 (c) and Figure 8 As shown in (d) of FIG. 1 , the semiconductor wafer W is cut by temporarily expanding the dicing tape T1 holding the semiconductor wafer W subjected to the laser stealth dicing. Specifically, first, as Figure 8 As shown in (c), the hollow cylindrical lifting member 32 of the expansion device abuts against the dicing tape T1 from its lower side and rises, and the dicing tape T1 attached with the semiconductor wafer W is expanded in a manner of being stretched along two-dimensional directions including the radial and circumferential directions of the semiconductor wafer W. The temperature conditions during expansion are, for example, -20 to 70°C. Through this expansion, cracks are formed in the brittle region F in the semiconductor wafer W, and singulation into semiconductor chips 11 occurs. Thereafter, as Figure 8 As shown in (d), the lifting member 32 is lowered, and the expanded state of the dicing tape T1 is released. After expansion, the portion of the dicing tape T1 that is closer to the outside than the semiconductor wafer segment holding area can be heated to shrink. The heating temperature is, for example, 100 to 300° C. This configuration is preferred for suppressing the narrowing of the spacing distance between the semiconductor chips 11 after expansion.

[0095] By this dividing step, the semiconductor wafer divided body 10 can also be formed on the dicing tape T1. The distance between the semiconductor chips 11 of the semiconductor wafer divided body 10 formed in this way is, for example, 10 to 500 μm. The formed semiconductor wafer divided body 10 is supplied to the reference Figure 1 (c) The pasting step described above.

[0096] In the semiconductor device manufacturing method as described above, referring to Figure 1 (c) In the pasting process described above, a sintering bonding sheet 20 for supplying a sintering bonding material is pasted to the semiconductor wafer divided body 10 (including a plurality of singulated semiconductor chips 11) on the dicing tape T1. This configuration is suitable for efficiently supplying a sintering bonding material to each of the plurality of semiconductor chips 11 at once, that is, transferring and forming a sintering bonding material layer 21 for each of the plurality of semiconductor chips 11.

[0097] Furthermore, in the present semiconductor device manufacturing method, the chip-to-chip distance of the semiconductor wafer segment 10 (i.e., the semiconductor wafer W that has been singulated into chips while being maintained on the dicing tape T1) formed on the dicing tape T1 by the segmentation process is, as described above, for example, 10 to 500 μm. The chip-to-chip distance is, for example, shorter, using a value smaller than the thickness of the semiconductor chip. In the pasting process, a sintering bonding sheet 20 is pasted to the semiconductor wafer segment 10 (the sintering bonding sheet 20 is not pasted to a plurality of semiconductor chips that are arranged on a predetermined processing tape after the semiconductor wafer W has been singulated and that have large gaps between the chips). Therefore, the present semiconductor device manufacturing method is suitable for reducing the loss of sintering bonding material when the sintering bonding material is supplied to each of a plurality of semiconductor chips 11 at the same time.

[0098] As described above, the present semiconductor device manufacturing method is suitable for efficiently supplying the sinter-bonding material to each semiconductor chip 11 while reducing the loss of the sinter-bonding material.

[0099] Fig. 9 and Fig.10 A semiconductor device manufacturing method according to an embodiment of the present invention is shown. The semiconductor device manufacturing method of this embodiment is a method for manufacturing a semiconductor device such as a power semiconductor device having a sintered bonding portion of a semiconductor chip, and includes the following steps: a laser stealth cutting step, a pasting step, a cutting step, a picking step, a temporary fixing step, and a sintering bonding step.

[0100] In the laser invisible cutting process, first Fig. 9As shown in (a), after laser stealth cutting is performed on the semiconductor wafer W in a state where it is held on the dicing tape T1, a fragile region F for cutting into a plurality of semiconductor chips is formed in the semiconductor wafer W. Before or after such laser stealth cutting, the semiconductor wafer W can be thinned by grinding the back side (the upper surface in the figure in this embodiment). The semiconductor wafer W that has undergone laser stealth cutting is in a state where it can be cut along the fragile region F by maintaining the expansion of the dicing tape T1. The specific method and conditions for laser stealth cutting of the semiconductor wafer W are similar to those in reference. Figure 8 (a) is the same as described above.

[0101] In this embodiment, then Fig. 9 As shown in (b), a sintering bonding sheet 20 is pasted to the semiconductor wafer W (pasting process). As described above, the sintering bonding sheet 20 is a sheet of a composition comprising at least a binder component and sinterable particles containing a conductive metal, and is pasted from the side opposite to the dicing tape T1 relative to the semiconductor wafer W and / or its back side on the dicing tape T1. As a pressing means for pasting, for example, a pressure roller can be listed. The pasting temperature is, for example, in the range of room temperature to 200°C, and the load used for pasting is, for example, 0.01 to 10 MPa. In this process, the sintering bonding material can be efficiently supplied to each portion of the semiconductor wafer W to be singulated into a semiconductor chip, that is, the sintering bonding material layer can be transferred and formed for each portion of the semiconductor wafer W to be singulated into a semiconductor chip.

[0102] Then, if Fig.10 In this process, the expansion device is used to first Fig.10 As shown in (a) of FIG. 1 , the dicing tape T1 having the semiconductor wafer W with the sintered bonding sheet 20 and the ring frame R on the bonding surface T1a is fixed to the holding tool 31 of the expansion device. Fig.10 As shown in (b), the hollow cylindrical lifting member 32 of the expansion device abuts against the dicing tape T1 from its lower side and rises, and the dicing tape T1 attached with the semiconductor wafer W is expanded in a manner of being stretched along two-dimensional directions including the radial and circumferential directions of the semiconductor wafer W. The temperature conditions during expansion are, for example, -20 to 70°C. Through this expansion, cracks are formed in the brittle region F in the semiconductor wafer W, and singulation into semiconductor chips 11 occurs. Thereafter, as Fig.10As shown in (c), the lifting member 32 is lowered and the expanded state of the dicing tape T1 is released. As described above, in this cutting process, by temporarily expanding the dicing tape T1 holding the semiconductor wafer W, the semiconductor wafer W and the sintering bonding sheet 20 thereon can be cut together to form a semiconductor wafer segment 10 including a plurality of semiconductor chips 11 that are closely attached to the sintering bonding material layer 21 derived from the sintering bonding sheet 20. After the above-mentioned expansion, the portion of the dicing tape T1 that is closer to the outside than the semiconductor wafer segment holding area can be heated to shrink it. The heating temperature is, for example, 100 to 300°C. This configuration is preferred for suppressing the narrowing of the spacing distance between the semiconductor chips 11 after expansion.

[0103] In this embodiment, after the above-mentioned cutting process, the Figure 1 (d) In the above-described reversal process, refer to Figure 2 In the picking process described above, refer to Figure 3 (a) In the temporary fixing process described above, refer to Figure 3 (b) In the sintering bonding process described above, refer to Figure 4 (a) The wire bonding process described above, and the reference Figure 4 (b) The sealing process described above. In addition, in this embodiment, reference can be made to Figure 5 (a) In the above described picking process and reference Figure 5 (b) in the above-described inversion step, instead of referring to other embodiments Figure 1 (d) The inversion process described above and the reference Figure 2 The picking process described above.

[0104] As described above, a semiconductor device including a sintered bonded portion of a semiconductor chip can be manufactured.

[0105] In the semiconductor device manufacturing method of this embodiment, referring to Fig. 9 (b) In the pasting process described above, the sintering bonding sheet 20 for supplying the sintering bonding material is pasted to the semiconductor wafer W after the laser stealth dicing on the dicing tape T1. This structure is suitable for efficiently supplying the sintering bonding material to each part of the semiconductor wafer W to be singulated into semiconductor chips, that is, transferring and forming the sintering bonding material layer 21 to each part of the semiconductor wafer W to be singulated into semiconductor chips.

[0106] Furthermore, in the pasting process of the present embodiment, the sintering bonding sheet 20 is pasted to the semiconductor wafer W that has not been singulated into chips (i.e., the semiconductor wafer W without gaps between chips). In this pasting process, the sintering bonding sheet 20 for supplying the sintering bonding material can be pressed against the entire surface of the semiconductor wafer W in the region where it is pasted to the semiconductor wafer W. Therefore, the present semiconductor device manufacturing method is suitable for reducing the loss of the sintering bonding material supplied to the plurality of semiconductor chips 11 obtained in the process.

[0107] As described above, the present semiconductor device manufacturing method is suitable for efficiently supplying the sinter bonding material to each semiconductor chip 11 while reducing the loss of the sinter bonding material.

[0108] Fig.11 A part of the process of a semiconductor device manufacturing method according to an embodiment of the present invention is shown. The semiconductor device manufacturing method of this embodiment is a method for manufacturing a semiconductor device such as a power semiconductor device having a sintered bonding portion of a semiconductor chip, and includes the following pasting process, singulation process, pickup process, temporary fixing process and sintering bonding process.

[0109] During the pasting process, Fig.11 (a) and Fig.11 As shown in (b), a sintering bonding sheet 20 is pasted to the semiconductor wafer W held on the adhesive surface T1a of the dicing tape T1. As described above, the sintering bonding sheet 20 is a sheet of a composition containing at least a binder component and sinterable particles containing a conductive metal, and is pasted to the semiconductor wafer W and / or its back side on the dicing tape T1 from the side opposite to the dicing tape T1. As a pressing means for pasting, a pressure roller can be cited, for example. The pasting temperature is, for example, in the range of room temperature to 200°C, and the load for pasting is, for example, 0.01 to 10 MPa. In this process, the sintering bonding material can be efficiently supplied to each part of the semiconductor wafer W to be singulated into a semiconductor chip, that is, the sintering bonding material layer is transferred and formed for each part of the semiconductor wafer W to be singulated into a semiconductor chip. In addition, before this process, the semiconductor wafer W can be thinned by grinding its back side (the upper surface in the figure in this embodiment).

[0110] Then, if Fig.11The singulation process is performed as shown in (c). Specifically, while the semiconductor wafer W with the sintering bonding sheet 20 is maintained on the adhesive surface T1a of the dicing tape T1, a rotating blade (not shown) provided in the dicing device is driven to perform cutting processing on the semiconductor wafer W and the sintering bonding sheet 20 thereon. The cutting processing is performed along the predetermined cutting line while water is continuously supplied to the rotating blade and the semiconductor wafer W. Fig.11 In (c), the cutting groove G formed by the dicing rotary blade is schematically indicated by a thick line. The cutting depth of the cutting groove G can reach the inside of the dicing tape T1. By undergoing this singulation process, a semiconductor wafer divided body 10 including a plurality of semiconductor chips 11 in close contact with the sintering bonding material layer 21 derived from the sintering bonding sheet 20 is formed on the dicing tape T1.

[0111] In this embodiment, after the pasting process, Fig.11 The inversion step as shown in (d) is performed. Specifically, in this step, a wafer processing tape T2 having an adhesive surface T2a is adhered to the semiconductor wafer segment 10 with the sintering bonding sheet 20, that is, the workpiece, and the dicing tape T1 is peeled off from the workpiece. The adhesive force of the adhesive surface T2a of the processing tape T2 is equal to or greater than the adhesive force of the adhesive surface T1a of the processing tape T1. In this step, for example, on one side of the sintering bonding sheet 20 in the semiconductor wafer segment 10 with the sintering bonding sheet 20, the wafer processing tape T2 is adhered with its adhesive surface T2a side, and then the dicing tape T1 is peeled off from the semiconductor wafer segment 10.

[0112] In this embodiment, after the above-mentioned singulation process, the following steps are performed with reference to other embodiments. Figure 2 In the picking process described above, refer to Figure 3 (a) In the temporary fixing process described above, refer to Figure 3 (b) In the sintering bonding process described above, refer to Figure 4 (a) The wire bonding process described above, and the reference Figure 4 (b) The sealing process described above.

[0113] In this embodiment, the following picking-up process and the subsequent inversion process may be performed. Fig.11 (d) The inversion process described above and Figure 2 The picking process shown.

[0114] First, refer to Fig.11 (c) After the singulation process described above, Fig.12As shown in (a), the semiconductor chip 11 and the sintering bonding material layer 21 closely attached thereto are picked up from the dicing tape T1 together to obtain the semiconductor chip 11 with the sintering bonding material layer (picking up process). In this picking up process, the suction barrel clamp C used holds the semiconductor chip 11 by sucking the semiconductor chip 11 with the sintering bonding material layer toward the sintering bonding material layer 21 side. Next, as Fig.12 As shown in (b), the semiconductor chip 11 is transferred from the suction clamp C that has picked up the semiconductor chip 11 with the sintering bonding material layer to the other suction clamp C' (reversal process). The suction clamp C' holds the semiconductor chip 11 by sucking the semiconductor chip 11 with the sintering bonding material layer toward the chip side. The semiconductor chip 11 with the sintering bonding material layer is supplied to the reference Figure 3 (a) is the temporary fixing process described above.

[0115] In this embodiment, the following singulation process can be performed by laser stealth dicing, instead of referring to Fig.11 (c) The singulation step using the above-mentioned blade dicing described above.

[0116] First, if Fig.13 As shown in (a), after the semiconductor wafer W is subjected to the laser stealth dicing while being held on the dicing tape T1, a fragile region F for cutting into a plurality of semiconductor chips is formed in the semiconductor wafer W. The semiconductor wafer W subjected to the laser stealth dicing is in a state where it can be cut along the fragile region F by maintaining the expansion of the dicing tape T1. The specific method and conditions for the laser stealth dicing of the semiconductor wafer W are similar to those in the reference. Figure 8 (a) is the same as described above.

[0117] Then, if Fig.13 As shown in (b) of FIG. 1 , the dicing tape T1 having the semiconductor wafer W with the sintered bonding sheet 20 and the ring frame R on the bonding surface T1a is fixed to the holding tool 31 of the expansion device. Fig.13 As shown in (c), the hollow cylindrical lifting member 32 of the expansion device abuts against the dicing tape T1 from its lower side and rises, and the dicing tape T1 attached with the semiconductor wafer W is expanded in a manner of being stretched along two-dimensional directions including the radial and circumferential directions of the semiconductor wafer W. The temperature conditions during expansion are, for example, -20 to 70°C. Through this expansion, cracks are formed in the brittle region F in the semiconductor wafer W, and singulation into semiconductor chips 11 occurs. Thereafter, as Fig.13As shown in (d), the lifting member 32 is lowered and the expanded state in the dicing tape T1 is released. As described above, in this singulation process, by temporarily expanding the dicing tape T1 holding the semiconductor wafer W, the semiconductor wafer W and the sintering bonding sheet 20 thereon can be cut together to form a semiconductor wafer segment 10 including a plurality of semiconductor chips 11 that are closely attached to the sintering bonding material layer 21 derived from the sintering bonding sheet 20. After the above-mentioned expansion, the portion of the dicing tape T1 that is closer to the outside than the semiconductor wafer segment holding area can be heated to shrink it. The heating temperature is, for example, 100 to 300°C. This configuration is preferred for suppressing the narrowing of the spacing distance between the semiconductor chips 11 after expansion.

[0118] As described above, a semiconductor device including a sintered bonded portion of a semiconductor chip can be manufactured.

[0119] In the semiconductor device manufacturing method of this embodiment, referring to Fig.11 (b) In the pasting process described above, as described above, the sintering bonding sheet 20 for supplying the sintering bonding material is pasted to the semiconductor wafer W on the dicing tape T1. This structure is suitable for efficiently supplying the sintering bonding material to each portion of the semiconductor wafer W to be singulated into the semiconductor chip 11, that is, transferring and forming the sintering bonding material layer to each portion of the semiconductor wafer W to be singulated into the semiconductor chip.

[0120] Furthermore, in the above-mentioned pasting process of the present semiconductor device manufacturing method, the sintering bonding sheet 20 is pasted to the semiconductor wafer W that has not been singulated into chips (that is, the semiconductor wafer W without gaps between chips). In this pasting process, the sintering bonding sheet 20 for supplying the sintering bonding material can be pressed against the entire surface of the semiconductor wafer W in the area where it is pasted to the semiconductor wafer W. Therefore, the present semiconductor device manufacturing method is suitable for reducing the loss of the sintering bonding material supplied to the plurality of semiconductor chips 11 obtained in the process.

[0121] As described above, the present semiconductor device manufacturing method is suitable for efficiently supplying the sinter bonding material to each semiconductor chip 11 while reducing the loss of the sinter bonding material.

[0122] Description of Reference Numerals

[0123] W Semiconductor Wafer

[0124] G Cutting groove

[0125] F Vulnerable Area

[0126] 10 Semiconductor wafer separation unit

[0127] 11. Semiconductor Chip

[0128] 20 Sintering bonding sheet

[0129] 21 Sintering bonding material layer

[0130] 22 Sintering layer

[0131] T1 Cutting Tape

[0132] T2 Wafer Processing Tape

[0133] S Support substrate (substrate)

Claims

1. A method for manufacturing a semiconductor device, comprising the following steps: A dividing step of forming a semiconductor wafer divided body including a plurality of semiconductor chips from the semiconductor wafer held on a dicing tape; A pasting step of pasting a sintering bonding sheet containing a pyrolyzable polymer binder component and sintering particles containing a conductive metal to the semiconductor wafer segment on the dicing tape from a side opposite to the dicing tape, and transferring a sintering bonding material layer from the sintering bonding sheet to each of the semiconductor chips; A picking-up step of picking up the semiconductor chip and the sintering bonding material layer closely attached thereto together to obtain a semiconductor chip with the sintering bonding material layer; A temporary fixing step of temporarily fixing the semiconductor chip with the sintering bonding material layer to the substrate via the sintering bonding material layer; as well as The bonding step is a step of bonding the semiconductor chip to the substrate by subjecting the sintering bonding material layer interposed between the temporarily fixed semiconductor chip and the substrate to a heating process to form a sintered layer.

2. The method for manufacturing a semiconductor device according to claim 1, wherein: In the dividing step, the semiconductor wafer divided bodies are formed by dicing the semiconductor wafer with a blade.

3. The method for manufacturing a semiconductor device according to claim 1 or 2, wherein: The method further includes, between the dividing step and the pasting step, temporarily expanding the dicing tape holding the divided semiconductor wafer bodies.

4. The method for manufacturing a semiconductor device according to claim 1 or 2, wherein: The method further includes, between the pasting step and the picking-up step, temporarily expanding the dicing tape holding the divided semiconductor wafer bodies.

5. The method for manufacturing a semiconductor device according to claim 1, wherein: In the dividing step, after a fragile region for dividing into a plurality of semiconductor chips is formed in the semiconductor wafer held on a dicing tape, the semiconductor wafer is divided by expanding the dicing tape holding the semiconductor wafer to form the semiconductor wafer divided bodies.

6. The method for manufacturing a semiconductor device according to claim 1 or 2, wherein: In the pickup step, the semiconductor chip with the sinter-bonding material layer is picked up from the dicing tape.

7. The method for manufacturing a semiconductor device according to claim 1 or 2, wherein: Between the pasting step and the picking-up step, the following steps are included: pasting a wafer processing tape to the sintering bonding sheet side of the semiconductor wafer segment with the sintering bonding sheet, and peeling the dicing tape from the semiconductor wafer segment, In the pickup step, the semiconductor chip with the sinter-bonding material layer is picked up from the wafer processing tape.

8. The method for manufacturing a semiconductor device according to claim 4, wherein: Between the expansion step and the pick-up step, the following steps are included: a step of attaching a wafer processing tape to the sintering bonding material layer side of the semiconductor wafer segment including a plurality of semiconductor chips closely attached to the sintering bonding material layer derived from the sintering bonding sheet, and a step of peeling off the dicing tape from the semiconductor wafer segment; In the pickup step, the semiconductor chip with the sinter-bonding material layer is picked up from the wafer processing tape.

9. A method for manufacturing a semiconductor device, comprising the following steps: A step of forming a fragile region for cutting into a plurality of semiconductor chips in a semiconductor wafer held on a dicing tape; a pasting step of pasting a sintering bonding sheet containing a pyrolyzable polymer binder component and sinterable particles containing a conductive metal to the semiconductor wafer on the dicing tape from a side opposite to the dicing tape; A cutting step of expanding the dicing tape holding the semiconductor wafer to cut the semiconductor wafer together with the sintered bonding sheet to form a semiconductor wafer divided body including a plurality of semiconductor chips in close contact with a sintered bonding material layer derived from the sintered bonding sheet; A picking-up step of picking up the semiconductor chip and the sintering bonding material layer closely attached thereto together to obtain a semiconductor chip with the sintering bonding material layer; A temporary fixing step of temporarily fixing the semiconductor chip with the sintering bonding material layer to the substrate via the sintering bonding material layer; as well as In the bonding step, the sintering bonding material layer interposed between the temporarily fixed semiconductor chip and the substrate is subjected to a heating process to form a sintered layer, thereby bonding the semiconductor chip to the substrate.

10. A method for manufacturing a semiconductor device, comprising the following steps: a sticking step of sticking a sintering bonding sheet containing a pyrolyzable polymer binder component and sinterable particles containing a conductive metal to the semiconductor wafer held on the dicing tape from a side opposite to the dicing tape; A singulation step of singulating the semiconductor wafer on the dicing tape together with the sintering bonding sheet to form semiconductor wafer divided bodies including a plurality of semiconductor chips in close contact with a sintering bonding material layer derived from the sintering bonding sheet; A picking-up step of picking up the semiconductor chip and the sintering bonding material layer closely attached thereto together to obtain a semiconductor chip with the sintering bonding material layer; A temporary fixing step of temporarily fixing the semiconductor chip with the sintering bonding material layer to the substrate via the sintering bonding material layer; as well as The bonding step is a step of bonding the semiconductor chip to the substrate by subjecting the sintering bonding material layer interposed between the temporarily fixed semiconductor chip and the substrate to a heating process to form a sintered layer.

11. The method for manufacturing a semiconductor device according to claim 10, wherein: In the singulation step, the semiconductor wafer divided bodies are formed by dicing the semiconductor wafer and the sintered bonding sheet thereon with a blade.

12. The method for manufacturing a semiconductor device according to claim 10, wherein: In the singulation process, after a fragile area for cutting into a plurality of semiconductor chips is formed in the semiconductor wafer which is held on the dicing tape, the semiconductor wafer and the sintered bonding sheet thereon are cut by expanding the dicing tape which holds the semiconductor wafer, thereby forming the semiconductor wafer divided body.

13. The method for manufacturing a semiconductor device according to any one of claims 9 to 12, wherein: In the pickup step, the semiconductor chip with the sinter-bonding material layer is picked up from the dicing tape.

14. The method for manufacturing a semiconductor device according to any one of claims 9 to 12, wherein: Prior to the picking up step, the following steps are included: a step of attaching a wafer processing tape to the sintering bonding material layer side of the semiconductor wafer segment including a plurality of semiconductor chips closely attached to the sintering bonding material layer derived from the sintering bonding sheet, and a step of peeling off the dicing tape from the semiconductor wafer segment; In the pickup step, the semiconductor chip with the sinter-bonding material layer is picked up from the wafer processing tape.

15. The method for manufacturing a semiconductor device according to claim 1 or 2, wherein: The thickness of the sintered layer is in the range of 60 to 140% of the average thickness of the sintered layer.

16. The method for manufacturing a semiconductor device according to claim 1 or 2, wherein: The average thickness of the sintered layer is 5 to 200 μm.

17. The method for manufacturing a semiconductor device according to claim 1 or 2, wherein: The sinterable particles include at least one selected from the group consisting of silver, copper, silver oxide, and copper oxide.

18. The method for manufacturing a semiconductor device according to claim 1 or 2, wherein: The semiconductor device is a power semiconductor device.

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