Method of manufacturing semiconductor device

Abstract

To provide a semiconductor device that can stably operate.SOLUTION: A method of manufacturing a semiconductor device includes a first film deposition stage of forming a first electrode layer on a substrate reverse surface facing the side opposed to a device surface where a circuit part is formed between outer surfaces of a base material. The method also includes a second film deposition stage of forming a second electrode layer on the top surface of a film-deposited member. The method further includes a joining stage of joining the first electrode layer and second electrode layer together. The method furthermore includes a film-deposited member removal stage of removing the film-deposited member from the second electrode layer.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] An embodiment of the present invention relates to a method for manufacturing a semiconductor device. [Background technology]

[0002] In semiconductor devices, the thickness of the substrate may be thinned to improve the characteristics of the semiconductor device. Also, in semiconductor devices, the amount of heat generated by the circuit portion formed on the substrate tends to be large. As a result, the temperature of the semiconductor device tends to increase, and if the temperature of the semiconductor device becomes too high, there is a risk that the operation of the semiconductor device will become unstable. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2014-17333 A Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present invention is to provide a semiconductor device that can operate stably. [Means for solving the problem]

[0005] A method for manufacturing a semiconductor device according to an embodiment includes a first film formation step of forming a first electrode layer on the back surface of the substrate, the back surface facing the opposite side to the device surface on which the circuit portion is formed, a second film formation step of forming a second electrode layer on the surface of a film-formed member, a bonding step of bonding the first electrode layer and the second electrode layer, and a film-formed member removal step of removing the film-formed member from the second electrode layer. [Brief description of the drawings]

[0006] [Figure 1] 1 is a schematic cross-sectional view showing a semiconductor device according to a first embodiment. [Diagram 2]3 is a flowchart showing a method for manufacturing the semiconductor device according to the first embodiment. [Diagram 3] 5 is a schematic cross-sectional view showing a device surface forming step according to the first embodiment. FIG. [Figure 4] FIG. 4 is a schematic cross-sectional view showing a first attaching step in the first embodiment. [Diagram 5] FIG. 4 is a schematic cross-sectional view showing a first film forming step according to the first embodiment. [Figure 6] FIG. 4 is a schematic cross-sectional view showing a second film forming step in the first embodiment. [Figure 7] 5A to 5C are schematic cross-sectional views showing a bonding step in the first embodiment. [Figure 8] 5A to 5C are schematic cross-sectional views illustrating a film-formed member removing step in the first embodiment. [Figure 9] FIG. 4 is a schematic cross-sectional view showing a second attaching step in the first embodiment. [Figure 10] 10A to 10C are first schematic cross-sectional views showing a supporting substrate removing step according to the first embodiment. [Figure 11] 11 is a second schematic cross-sectional view showing the supporting substrate removing step of the first embodiment. FIG. [Figure 12] FIG. 4 is a first schematic cross-sectional view showing a singulation step according to the first embodiment. [Figure 13] FIG. 4 is a second schematic cross-sectional view showing the singulation step of the first embodiment. [Figure 14] 10 is a flowchart showing a method for manufacturing a semiconductor device according to a second embodiment. [Figure 15] FIG. 11 is a schematic cross-sectional view showing a second film forming step according to the second embodiment. [Figure 16] 13A to 13C are schematic cross-sectional views illustrating a film-formation member removing step according to a second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0007] Hereinafter, a method for manufacturing a semiconductor device according to an embodiment will be described with reference to the drawings.

[0008] In the following description, in order to indicate the positional relationship of each component and each layer constituting the semiconductor device, the upper side of each drawing will be referred to as the "upper side", the lower side of each drawing will be referred to as the "lower side", and the up-down direction of each drawing will be referred to as the "upper direction". Note that "upper side", "lower side", and "up-down direction" are not terms that indicate a relationship with the direction of gravity. In the following description, the surface facing upward among the outer surfaces of each component and each layer constituting the semiconductor device will be referred to as the front side, and the surface facing downward will be referred to as the back side.

[0009] (First embodiment) 1 is a schematic cross-sectional view of a semiconductor device 1 according to the present embodiment. The semiconductor device 1 according to the present embodiment is, for example, a semiconductor device such as a MOSFET or an IGBT (Insulated Gate Bipolar Transistor). The semiconductor device 1 according to the present embodiment includes a rectangular plate-shaped semiconductor chip 10T, a circuit section 12, a front surface electrode section 15, and a back surface electrode section 30.

[0010] The semiconductor chip 10T is made of a semiconductor material. In this embodiment, the semiconductor material constituting the semiconductor chip 10T may be, for example, silicon (Si), silicon carbide (SiC), gallium arsenide (GaAs), gallium nitride (GaN), or the like, but is not limited thereto.

[0011] The circuit section 12 is formed on a device surface 10a which is the surface of the semiconductor chip 10T. The circuit section 12 is composed of, for example, a plurality of devices such as semiconductor elements constituting MOSFETs, and a circuit pattern electrically connecting each device.

[0012] The surface electrode portion 15 is formed on the surface 12a of the circuit portion 12. For example, when the semiconductor device 1 is a MOSFET, the surface electrode portion 15 includes a gate electrode and a source electrode of the MOSFET. The surface electrode portion 15 includes a material having electrical conductivity. Examples of materials that can be used for the surface electrode portion 15 include, but are not limited to, metals such as copper, aluminum, nickel, silver, and gold, and alloys containing at least one of these metals.

[0013] The back electrode unit 30 is formed on the back surface 10b of the substrate, which is the back surface of the semiconductor chip 10T. For example, when the semiconductor device 1 is a MOSFET, the back electrode unit 30 is a drain electrode of the MOSFET. The back electrode unit 30 includes a material having electrical conductivity. The material constituting the back electrode unit 30 may be, for example, a metal such as copper, aluminum, nickel, silver, or gold, or an alloy containing at least one of these metals, but is not limited thereto. In this embodiment, the back electrode unit 30 is made of copper. The back electrode unit 30 has a first electrode layer 31 and a second electrode layer 32.

[0014] The first electrode layer 31 is formed on the back surface 10b of the substrate of the semiconductor chip 10T. In this embodiment, the first electrode layer 31 is made of copper. The second electrode layer 32 is formed on the back surface 31b of the first electrode layer 31. The second electrode layer 32 is joined to the first electrode layer 31. In this embodiment, the second electrode layer 32 is made of copper. The thickness of the second electrode layer 32 is thicker than the thickness of the first electrode layer 31. In this embodiment, the thickness of the second electrode layer 32 is preferably in the range of 10 μm or more and 50 μm or less. In this embodiment, the thickness of the second electrode layer 32 is about 20 μm. The thickness of the second electrode layer 32 may be thinner than 10 μm or thicker than 50 μm.

[0015] 2 is a flowchart showing a method for manufacturing the semiconductor device 1 of this embodiment. The method for manufacturing the semiconductor device 1 of this embodiment includes a device surface forming step S01, a first bonding step S02, a grinding step S03, a first film forming step S04, a second film forming step S05, a bonding step S06, a film-formed member removing step S07, a second bonding step S08, a support substrate removing step S09, a singulation step S10, and a pick-up step S11. In the following description, "workers, etc." includes workers and assembly devices that perform the work of each process. The work of each process may be performed only by the workers, only by the assembly device, or by both the workers and the assembly device.

[0016] As shown in FIG. 3, the device surface forming step S01 is a step of forming a circuit part 12 and a front surface electrode part 15 on the device surface 10a of the substrate 10. First, an operator forms a plurality of circuit parts 12 on the device surface 10a, which is the surface of the disk-shaped substrate 10 (semiconductor wafer) made of a semiconductor material. The device surface 10a is the surface facing the upper side of the outer surface of the substrate 10. The circuit parts 12 are formed at intervals from each other. The plurality of circuit parts 12 are formed side by side in the left-right direction of FIG. 3. Although not shown, the plurality of circuit parts 12 may be formed side by side in a direction perpendicular to the paper surface of FIG. 3. In this case, the circuit parts 12 are arranged side by side in the left-right direction of FIG. 3 and in the direction perpendicular to the paper surface of FIG. 3. In the following description, in the step before the grinding step S03, the surface facing the opposite side to the device surface 10a of the outer surface of the substrate 10 is the initial back surface 10f.

[0017] Next, an operator or the like forms a front surface electrode portion 15 on the front surface 12a of each circuit portion 12. In this embodiment, the front surface electrode portion 15 is formed by a physical vapor deposition method such as sputtering. When the front surface electrode portion 15 is formed on the front surface 12a of each circuit portion 12, the device surface forming step S01 is completed.

[0018] As shown in FIG. 4, the first attachment step S02 is a step of attaching the support substrate 20 to the device surface 10a of the base material 10 with an adhesive 25. The first attachment step S02 is a step prior to the first film forming step S04. An operator or the like first applies uncured adhesive 25 to the device surface 10a. The adhesive 25 is also applied to the surface of each front electrode portion 15, between the front electrode portions 15, and between the circuit portions 12. As the adhesive 25, for example, an acrylic adhesive, an epoxy adhesive, or a silicone adhesive can be used.

[0019] Next, the worker or the like bonds the device surface 10a of the base material 10 and the back surface 20b of the support substrate 20 with the adhesive 25. In this embodiment, the support substrate 20 is a plate-shaped member made of, for example, glass and silicon. In this embodiment, the support substrate 20 is translucent. A release layer 22 is formed on the back surface 20b of the support substrate 20. In this embodiment, the release layer 22 contains carbon. The release layer 22 is black. Next, the worker or the like hardens the adhesive 25 to bond the support substrate 20 to the device surface 10a. As a result, the base material 10 is supported by the support substrate 20. When the support substrate 20 is bonded to the device surface 10a, the first bonding step S02 is completed.

[0020] As shown in FIG. 5, the grinding step S03 is a step of forming a substrate back surface 10b by grinding a lower portion of the substrate 10 to reduce the thickness of the substrate 10. An operator grinds the lower portion of the substrate 10 while the substrate 10 is supported by the support substrate 20. When the lower portion of the substrate 10 is ground, the substrate 10 becomes thinner. That is, in the grinding step S03, the substrate 10 is thinned. In addition, the substrate back surface 10b of the substrate 10 is formed by grinding the lower portion of the substrate 10. The substrate back surface 10b is a surface facing downward among the outer surfaces of the substrate 10. The substrate back surface 10b is a surface facing the opposite side to the device surface 10a. When the substrate back surface 10b is formed, the grinding step S03 ends.

[0021] The first film formation step S04 is a step of forming a first electrode layer 31 on the back surface 10b of the base material 10. The first film formation step S04 is performed in a state in which the base material 10 is supported by the support substrate 20. In this embodiment, the first electrode layer 31 is formed by physical vapor deposition. More specifically, the first electrode layer 31 is formed by sputtering. The first electrode layer 31 may be formed by other physical vapor deposition methods such as thermal evaporation, or may be formed by chemical vapor deposition. As described above, in this embodiment, the first electrode layer 31 is made of copper. The first electrode layer 31 is formed with a uniform thickness over the entire back surface 10b of the base material. The thickness of the first electrode layer 31 is, for example, about 1 μm. The thickness of the first electrode layer 31 may be smaller than 1 μm or larger than 1 μm. When the first electrode layer 31 is formed on the back surface 10b of the base material, the first film formation step S04 is completed. Although not shown in the drawings, in this embodiment, the first electrode layer 31 is formed on the back surface 10b of the base material via a laminate film made of, for example, titanium (Ti) and copper. This makes it possible to suppress the copper constituting the first electrode layer 31 from diffusing into the base material 10.

[0022] As shown in FIG. 6, the second film forming step S05 is a step of forming a second electrode layer 32 on the surface 40a of the film-formed member 40. In this embodiment, the film-formed member 40 is made of a semiconductor material. Examples of the semiconductor material constituting the film-formed member 40 include, but are not limited to, silicon, silicon carbide, gallium arsenide, and gallium nitride. The film-formed member 40 may be made of other materials such as metal. In this embodiment, the film-formed member 40 is disk-shaped. The shape of the film-formed member 40 may be other shapes such as a cylindrical shape. In the second film forming step S05, the worker first forms an intermediate layer 42 on the surface 40a of the film-formed member 40. The intermediate layer 42 is made of aluminum and a material containing aluminum atoms such as alumina (Al2O3). In this embodiment, the intermediate layer 42 is made of alumina.

[0023] Next, the worker or the like forms the second electrode layer 32 on the surface 42a of the intermediate layer 42. In the second film forming step S05, the second electrode layer 32 is formed on the surface 40a of the film-formed member 40 via the intermediate layer 42. In this embodiment, the second electrode layer 32 is formed by plating. More specifically, a laminated film (not shown) made of titanium and copper is formed as a seed layer on the surface 42a of the intermediate layer 42 by sputtering, and then the second electrode layer 32 is formed on the laminated film. The laminated film may be removed as necessary to expose the second electrode layer 32 after removing the film-formed member 40 from the second electrode layer 32 in the film-formed member removing step S07. The thickness of the second electrode layer 32 is preferably in the range of 10 μm or more and 50 μm or less. In this embodiment, the thickness of the second electrode layer 32 is about 20 μm. The thickness of the second electrode layer 32 is thicker than the thickness of the first electrode layer 31. As described above, in this embodiment, the second electrode layer 32 is made of copper. Therefore, the first electrode layer 31 and the second electrode layer 32 are made of the same material. When the second electrode layer 32 is formed on the surface 40a of the film-formed member 40, the second film-formation step S05 is completed.

[0024] The bonding step S06 is a step of bonding the first electrode layer 31 and the second electrode layer 32 to form the back electrode part 30. The bonding step S06 is performed in a vacuum inside a chamber (not shown). As shown in FIG. 6, the worker or the like moves the film-formed member 40 with the surface 40a facing upward from the lower side to the upper side of the base material 10, and presses the film-formed member 40 against the base material 10. As a result, as shown in FIG. 7, the surface 32a of the second electrode layer 32 is pressed against the back surface 31b of the first electrode layer 31. Next, the worker or the like heats at least one of the first electrode layer 31 and the second electrode layer 32 while pressing the surface 32a of the second electrode layer 32 against the back surface 31b of the first electrode layer 31. As a result, the surface 32a of the second electrode layer 32 and the back surface 31b of the first electrode layer 31 are bonded to each other. That is, the first electrode layer 31 and the second electrode layer 32 are bonded to each other. When the first electrode layer 31 and the second electrode layer 32 are bonded to each other, the back electrode unit 30 is formed. When the back electrode unit 30 is formed, the bonding step S06 is completed.

[0025] According to this embodiment, as shown in FIG. 2, the manufacturing method of the semiconductor device 1 includes a first attachment step S02 in which the support substrate 20 is attached to the device surface 10a of the substrate 10 by the adhesive 25 before the first film-forming step S04. Therefore, the substrate 10 thinned in the grinding step S03 can be stably supported by the support substrate 20. Therefore, in the first film-forming step S04, the thinned substrate 10 can be prevented from deforming in the vertical direction. Therefore, in the first film-forming step S04, the uniformity of the thickness of the first electrode layer 31 formed on the substrate back surface 10b can be improved, and the bonding strength between the first electrode layer 31 and the second electrode layer 32 can be prevented from varying. This can increase the strength of the back electrode portion 30.

[0026] As shown in FIG. 8, the film-formed member removing step S07 is a step of removing the film-formed member 40 from the second electrode layer 32. First, an operator or the like immerses at least the intermediate layer 42 in water stored in a bathtub (not shown). When the intermediate layer 42 is immersed in water, the water penetrates into the interface between the intermediate layer 42 and the second electrode layer 32. This can reduce the bonding strength between the intermediate layer 42 and the second electrode layer 32. This is considered to be due to the following phenomenon. First, the intermediate layer 42 containing aluminum atoms undergoes a hydration reaction with the penetrated water, and alumina hydrate crystals grow on the surface 42a of the intermediate layer 42. Therefore, the surface roughness of the surface 42a of the intermediate layer 42 increases, and the contact area between the surface 42a of the intermediate layer 42 and the back surface 32b of the second electrode layer 32 decreases. This reduces the bonding strength between the intermediate layer 42 and the second electrode layer 32. The intermediate layer 42 and the film-formed member 40 may be immersed in the water, or in addition to the intermediate layer 42 and the film-formed member 40, the portion from the support substrate 20 to the second electrode layer 32 may also be immersed in the water.

[0027] Next, the worker holds the support substrate 20 with one jig or the like (not shown) while holding the film-formed member 40 with the other jig or the like (not shown), and moves the other jig downward with respect to the one jig. As described above, since the bonding strength between the intermediate layer 42 and the second electrode layer 32 is reduced, the intermediate layer 42 can be peeled off from the second electrode layer 32 by moving the other jig downward with respect to the one jig. This allows the worker to remove the intermediate layer 42 and the film-formed member 40 from the second electrode layer 32. That is, in the film-formed member removing step S07, at least the intermediate layer 42 is immersed in water, and then the film-formed member 40 is removed from the second electrode layer 32.

[0028] According to this embodiment, in the film-formed member removing step S07, as described above, the intermediate layer 42 is immersed in water to reduce the bonding strength between the intermediate layer 42 and the second electrode layer 32, so that the intermediate layer 42 can be easily peeled off from the second electrode layer 32. This allows the film-formed member 40 to be easily removed from the second electrode layer 32. For example, when a mixed acid solution such as nitric acid and hydrofluoric acid is permeated into the intermediate layer 42 to deteriorate the intermediate layer 42 and reduce the bonding strength between the intermediate layer 42 and the second electrode layer 32, if the mixed acid solution adheres to the adhesive 25, the adhesive 25 may deteriorate. Therefore, there is a risk that the adhesive strength between the support substrate 20 and the base material 10 may decrease. In contrast, in this embodiment, the bonding strength between the intermediate layer 42 and the second electrode layer 32 is reduced by water, so that the adhesive 25 does not deteriorate even if water adheres to the adhesive 25. Therefore, in this embodiment, it is possible to suppress a decrease in the adhesive strength between the support substrate 20 and the base material 10.

[0029] Furthermore, according to the present embodiment, as described above, the bonding strength between the intermediate layer 42 and the second electrode layer 32 is reduced by water without using a mixed acid solution such as nitric acid and hydrofluoric acid. This makes it possible to prevent the mixed acid solution from adhering to the circuit portion 12 and the front electrode portion 15, thereby preventing the circuit portion 12 and the front electrode portion 15 from deteriorating. This makes it possible to suppress a decrease in the yield of the semiconductor device 1 and to increase the stability of the operation of the semiconductor device 1.

[0030] In this embodiment, the water is warm water. In this embodiment, the temperature of the water is 50° C. or more and 100° C. or less. Therefore, according to this embodiment, the reaction between the intermediate layer 42 and the water can be favorably promoted. Therefore, the bonding strength between the intermediate layer 42 and the second electrode layer 32 can be stably reduced, so that the film-formed member 40 can be easily removed from the second electrode layer 32. The temperature of the water is preferably high, and the temperature of the water is preferably close to 100° C. When the film-formed member 40 is removed from the second electrode layer 32, the film-formed member removing step S07 ends. In addition, the method of removing the film-formed member 40 from the second electrode layer 32 in the film-formed member removing step S07 is not limited to the method of this embodiment. For example, the film-formed member 40 may be removed from the second electrode layer 32 by grinding the film-formed member 40 by grinding. In this case, the intermediate layer 42 may be removed from the second electrode layer 32 by grinding the intermediate layer 42 by grinding.

[0031] 9, the second attachment step S08 is a step of attaching a dicing tape 50 to the back surface 32b of the second electrode layer 32. The dicing tape 50 fixes the individual semiconductor chips 10T when the base material 10 is diced in the singulation step S10 described later. The dicing tape 50 is attached to the back surface 32b of the second electrode layer 32. That is, the dicing tape 50 is attached to the back surface 30b of the back surface electrode portion 30. When an operator or the like attaches the dicing tape 50 to the back surface 32b of the second electrode layer 32, the second attachment step S08 is completed.

[0032] According to this embodiment, as described above, in the film-forming member removal step S07, the bonding strength between the intermediate layer 42 and the second electrode layer 32 can be reduced by water, so that the deterioration of the adhesive 25 can be suppressed. This makes it possible to suppress a decrease in the adhesive force between the support substrate 20 and the base material 10. Therefore, in the second attachment step S08, the base material 10 can be stably supported by the support substrate 20, so that the dicing tape 50 can be easily attached to the back surface 30b of the back surface electrode portion 30. This makes it possible to suppress an increase in the number of steps in the second attachment step S08.

[0033] According to this embodiment, as shown in FIG. 2, the manufacturing method of the semiconductor device 1 includes a first attachment step S02 in which the support substrate 20 is attached to the device surface 10a of the substrate 10 by the adhesive 25 before the first film formation step S04. Therefore, the substrate 10 thinned in the grinding step S03 can be stably supported by the support substrate 20. Therefore, in each of the steps of the bonding step S06, the film-formed member removing step S07, and the second attachment step S08, which are steps subsequent to the first film formation step S04, the shape of the substrate 10 in the vertical direction and the position of the substrate 10 in the vertical direction can be stabilized. Therefore, in the bonding step S06, the first electrode layer 31 and the second electrode layer 32 can be easily bonded. Also, in the film-formed member removing step S07, the film-formed member 40 can be easily removed from the second electrode layer 32. Furthermore, in the second attachment step S08, the dicing tape 50 can be easily attached to the back surface 30b of the back surface electrode portion 30. Therefore, the steps of the bonding step S06, the film-formation member removing step S07, and the second attaching step S08 can be simplified, and the number of steps required for manufacturing the semiconductor substrate 1 can be prevented from increasing.

[0034] The support substrate removing step S09 is a step of removing the support substrate 20 from the base material 10. As shown in FIG. 2, the support substrate removing step S09 is a step performed after the film-formed member removing step S07. As shown in FIG. 10, first, an operator or the like irradiates the support substrate 20 with a laser beam L while scanning a laser 95 arranged above the support substrate 20. As described above, since the support substrate 20 has translucency, the laser beam L passes through the inside of the support substrate 20 and is irradiated to the peeling layer 22. As described above, since the peeling layer 22 is black, the peeling layer 22 absorbs the laser beam L. This causes the temperature of the peeling layer 22 to rise, and the peeling layer 22 is separated from the support substrate 20. Thereafter, the adhesive 25 may be removed by peeling it off with an adhesive tape, or may be removed by dissolving it with a solvent.

[0035] Next, as shown in Fig. 11, the worker holds the support substrate 20 with one jig or the like (not shown) while holding the dicing tape 50 with the other jig or the like (not shown), and moves one jig upward with respect to the other jig. As described above, the adhesive strength between the adhesive 25 and each of the base material 10 and the front surface electrode portion 15 is reduced, so that the adhesive 25 can be easily peeled off from each of the base material 10 and the front surface electrode portion 15 by moving one jig upward with respect to the other jig. This allows the worker to easily remove the support substrate 20 and the adhesive 25 from the base material 10.

[0036] In the support substrate removal step S09, the adhesive 25 may be deteriorated by permeating a solvent into the adhesive 25, and the adhesive strength between the adhesive 25 and the substrate 10 and the front electrode portion 15 may be reduced, and then the support substrate 20 may be removed from the substrate 10. Alternatively, a sharp tool may be inserted between the substrate 10 and the support substrate 20 to peel off the adhesive 25 from the substrate 10, thereby removing the support substrate 20 from the substrate 10. In addition, in the support substrate removal step S09, after removing the support substrate 20 from the substrate 10, it is preferable to remove the adhesive 25 remaining on the device surface 10a and the front electrode portion 15 by adhering a tape (not shown) to the device surface 10a and the front electrode portion 15 and then peeling off the tape. This allows, for example, a stable electrical connection between the front electrode portion 15 and an external electrode (not shown) connected to the front electrode portion 15 when the semiconductor device 1 is used. Therefore, the stability of the operation of the semiconductor device 1 can be improved.

[0037] According to this embodiment, the manufacturing method of the semiconductor device 1 includes a supporting substrate removing step S09 for removing the supporting substrate 20 from the base material 10 after the film-formed member removing step S07. Therefore, in the film-formed member removing step S07, the base material 10 can be supported by the supporting substrate 20, and as described above, the intermediate layer 42 can be easily peeled off from the second electrode layer 32 by holding the supporting substrate 20 with one jig or the like and moving the film-formed member 40 downward with the other jig or the like. This simplifies the operation of removing the film-formed member 40 from the second electrode layer 32, and thus prevents an increase in the number of steps in the film-formed member removing step S07.

[0038] As shown in FIG. 12, the singulation step S10 is a step of singulating the substrate 10. The worker or the like singulates the substrate 10 and the back electrode portion 30 to divide the substrate 10 into a plurality of semiconductor chips 10T. In this embodiment, the worker or the like cuts the substrate 10 and the back electrode portion 30 with a dicing device 90 having a blade 91. At this time, the circuit portion 12 and the front electrode portion 15 are formed on the device surface 10a of each semiconductor chip 10T. In addition, the back electrode portion 30 is formed on the substrate back surface 10b of each semiconductor chip 10T. Thus, when the substrate 10 is singulated, a plurality of semiconductor devices 1 (see FIG. 1) are formed. Note that the dicing tape 50 is not cut in the singulation step S10. Therefore, each semiconductor device 1 is fixed by the dicing tape 50. Note that the substrate 10 and the back electrode portion 30 may be cut with a laser dicing device. When the base material 10 is singulated, the singulation step S10 is completed.

[0039] The pick-up step S11 is a step of individually removing the semiconductor devices 1 fixed to the dicing tape 50 from the dicing tape 50. As shown in FIG. 13, the worker first performs a process to weaken the adhesive strength of the adhesive layer (not shown) on the surface 50a of the dicing tape 50. The worker weakens the adhesive strength of the adhesive layer of the dicing tape 50 by, for example, irradiating the adhesive layer with ultraviolet light or heating the adhesive layer. Next, the worker pushes one semiconductor device 1 upward from the lower side of the dicing tape 50 with a member such as a pin (not shown), and applies negative pressure to the device surface 10a of the semiconductor device 1 by a removal device (not shown) to adsorb the semiconductor device 1 to the removal device, thereby individually removing the semiconductor device 1 from the dicing tape 50. When all the semiconductor devices 1 are removed from the dicing tape 50, the pick-up step S11 is completed. As shown in FIG. 2, when the pick-up step S11 is completed, the manufacturing process of the semiconductor device 1 is completed, and multiple semiconductor devices 1 are manufactured.

[0040] According to this embodiment, the manufacturing method of the semiconductor device 1 includes a first film forming step S04 of forming a first electrode layer 31 on the back surface 10b of the base material 10, a second film forming step S05 of forming a second electrode layer 32 on the front surface 40a of the film-forming member 40, a bonding step S06 of bonding the first electrode layer 31 and the second electrode layer 32, and a film-forming member removing step S07 of removing the film-forming member 40 from the second electrode layer 32. Thus, the back electrode section 30 can be formed by the first electrode layer 31 and the second electrode layer 32 bonded to each other. Therefore, the thickness of the back electrode section 30 can be made thicker than when the back electrode section 30 is formed by only one of the first electrode layer 31 or the second electrode layer 32. This can reduce the thermal resistance of the back electrode section 30, and therefore the amount of heat dissipated from the circuit section 12 to the outside of the semiconductor device 1 through the back electrode section 30 can be increased. Therefore, the temperature of the circuit section 12 can be prevented from becoming too high, and therefore the stability of the operation of the semiconductor device 1 can be improved.

[0041] Moreover, according to the present embodiment, as described above, the thickness of the back electrode portion 30 can be increased, and therefore the strength of the back electrode portion 30 can be increased. Therefore, the strength of the semiconductor device 1 can be increased. This makes it possible to suppress damage to the semiconductor device 1 due to stress applied to the semiconductor device 1 when removing the semiconductor device 1 from the dicing tape 50 in the pick-up process S11. Therefore, the yield of the semiconductor device 1 can be increased. Also, as described above, the strength of the semiconductor device 1 can be increased, and therefore it is possible to suppress damage to the semiconductor device 1 due to stress, such as thermal stress, applied to the semiconductor device 1 during use of the semiconductor device 1. Therefore, the stability of the operation of the semiconductor device 1 can be increased.

[0042] According to this embodiment, in the first film formation step S04, the first electrode layer 31 is formed by physical vapor deposition, and in the second film formation step S05, the second electrode layer 32 is formed by plating. Therefore, since the second electrode layer 32 is formed by plating, the number of steps required to form the second electrode layer 32 to a thickness of, for example, 10 μm or more can be reduced compared to when the second electrode layer 32 is formed by physical vapor deposition. Therefore, the number of steps required to form the back electrode portion 30 can be reduced compared to when the entire back electrode portion 30 is formed by physical vapor deposition.

[0043] Moreover, according to the present embodiment, in the second film-forming step S05, the second electrode layer 32 is formed by plating on the film-forming member 40, which is a member separate from the base material 10. This makes it possible to prevent the chemical solution used in the plating from adhering to the circuit unit 12 and the front electrode unit 15 formed on the device surface 10a of the base material 10. This makes it possible to prevent the circuit unit 12 and the front electrode unit 15 from being deteriorated by the chemical solution, thereby making it possible to prevent a decrease in the yield of the semiconductor device 1. Furthermore, since it is possible to prevent the circuit unit 12 and the front electrode unit 15 from being deteriorated, it is possible to improve the stability of the operation of the semiconductor device 1.

[0044] Further, according to the present embodiment, as described above, in the second film forming step S05, the second electrode layer 32 is formed on the film-formed member 40, which is a member separate from the base material 10, by plating, so that the above-mentioned chemical solution can be prevented from adhering to the adhesive 25. Therefore, the adhesive 25 can be prevented from deteriorating, so that the adhesive strength between the support substrate 20 and the base material 10 can be suppressed from decreasing. As a result, in each of the bonding step S06, the film-formed member removing step S07, and the second attaching step S08, the shape of the base material 10 in the vertical direction and the position of the base material 10 in the vertical direction can be stabilized. Therefore, as described above, the work in each of the bonding step S06, the film-formed member removing step S07, and the second attaching step S08 can be simplified, so that the number of steps for manufacturing the semiconductor substrate 1 can be suppressed from increasing.

[0045] According to this embodiment, the material constituting the first electrode layer 31 and the material constituting the second electrode layer 32 are the same material. Therefore, it is easier to increase the bonding strength between the first electrode layer 31 and the second electrode layer 32 compared to the case where the material constituting the first electrode layer 31 and the material constituting the second electrode layer 32 are different materials. As a result, the strength of the back electrode portion 30 can be more suitably increased, and the strength of the semiconductor device 1 can be more suitably increased. Therefore, in the pick-up step S11, the semiconductor device 1 can be more suitably prevented from being damaged by the stress applied to the semiconductor device 1 when the semiconductor device 1 is removed from the dicing tape 50. Therefore, the yield of the semiconductor device 1 can be more suitably increased. In addition, when the semiconductor device 1 is used, the semiconductor device 1 can be more suitably prevented from being damaged by the stress, such as thermal stress, applied to the semiconductor device 1. Therefore, the stability of the operation of the semiconductor device 1 can be more suitably increased.

[0046] Second embodiment FIG. 14 is a flowchart showing a method for manufacturing the semiconductor device 1 of this embodiment. The method for manufacturing the semiconductor device 1 of this embodiment includes a device surface forming step S01, a first attaching step S02, a grinding step S03, a first film forming step S04, a second film forming step S205, a bonding step S06, a film-formed member removing step S207, a second attaching step S08, a support substrate removing step S09, a singulation step S10, and a pick-up step S11. The work performed in the second film forming step S205 and the film-formed member removing step S207 of this embodiment is different from the work performed in the second film forming step S05 and the film-formed member removing step S07 of the first embodiment described above. The work of the other steps of the method for manufacturing the semiconductor device 1 of this embodiment is the same as the work of the other steps of the method for manufacturing the semiconductor device 1 of the first embodiment described above. In the following description, the same reference numerals are used for the components that are the same as those of the first embodiment described above, and the description thereof will be omitted.

[0047] As shown in FIG. 15, the second film forming step S205 is a step of forming the second electrode layer 32 on the surface 40a of the film-formed member 40. In this embodiment, the second electrode layer 32 is directly formed on the surface 40a of the film-formed member 40. The second electrode layer 32 is formed by plating. The thickness of the second electrode layer 32 is preferably in the range of 10 μm or more and 50 μm or less. In this embodiment, the thickness of the second electrode layer 32 is about 20 μm. The thickness of the second electrode layer 32 is thicker than the thickness of the first electrode layer 31. When the second electrode layer 32 is formed on the surface 40a of the film-formed member 40, the second film forming step S205 is completed. The other configurations of the film-formed member 40 and the second electrode layer 32 of this embodiment are the same as the other configurations of the film-formed member 40 and the second electrode layer 32 of the first embodiment described above.

[0048] 16, the film-formed member removing step S207 is a step of removing the film-formed member 40 from the second electrode layer 32. In this embodiment, an operator or the like uses a grinding device 297 to grind the film-formed member 40 to remove it from the second electrode layer 32. In this embodiment, the grinding device 297 is a surface grinding machine that grinds an object to be ground with a rotating disc-shaped grindstone. When the film-formed member 40 is removed from the second electrode layer 32, the film-formed member removing step S207 ends.

[0049] According to this embodiment, as shown in FIG. 16, the back electrode section 30 can be configured by the first electrode layer 31 and the second electrode layer 32 bonded to each other. Therefore, as in the above-described first embodiment, the thickness of the back electrode section 30 can be made thicker than when the back electrode section 30 is configured by only one of the first electrode layer 31 or the second electrode layer 32. This can reduce the thermal resistance of the back electrode section 30, thereby increasing the amount of heat dissipated from the circuit section 12 to the outside of the semiconductor device 1 via the back electrode section 30. Therefore, the temperature of the circuit section 12 can be prevented from becoming too high, thereby improving the stability of the operation of the semiconductor device 1.

[0050] Furthermore, according to this embodiment, as described above, the thickness of the back surface electrode portion 30 can be increased, and therefore the strength of the back surface electrode portion 30 can be increased. Therefore, the strength of the semiconductor device 1 can be increased. As a result, similar to the above-described first embodiment, damage to the semiconductor device 1 can be suppressed in the pick-up process S11. Therefore, the yield of the semiconductor device 1 can be increased. Furthermore, damage to the semiconductor device 1 can be suppressed when the semiconductor device 1 is in use. Therefore, the stability of the operation of the semiconductor device 1 can be increased.

[0051] According to at least one of the embodiments described above, a semiconductor device capable of stably operating can be provided by having a first film formation process for forming a first electrode layer on the back surface of the substrate opposite the device surface of the substrate, a second film formation process for forming a second electrode layer on the surface of a film-formed member, a bonding process for bonding the first electrode layer and the second electrode layer, and a film-formed member removal process for removing the film-formed member from the second electrode layer.

[0052] The method for manufacturing a semiconductor device according to the embodiment includes the following additional aspects. (Appendix 1) a first film formation step of forming a first electrode layer on a back surface of the substrate, the back surface facing the opposite side to a device surface on which a circuit portion is formed, among the outer surfaces of the substrate; a second film-forming step of forming a second electrode layer on a surface of the film-forming member; a bonding step of bonding the first electrode layer and the second electrode layer; and removing the film-formed member from the second electrode layer. A method for manufacturing a semiconductor device. (Appendix 2) In the second film-forming step, the second electrode layer is formed on the surface of the film-forming member via an intermediate layer containing aluminum atoms, In the film-formed member removing step, after immersing at least the intermediate layer in water, the film-formed member is removed from the second electrode layer. 2. A method for manufacturing the semiconductor device according to claim 1. (Appendix 3) The temperature of the water is 50°C or more and 100°C or less. 3. A method for manufacturing the semiconductor device according to claim 2. (Appendix 4) In the first film formation step, the first electrode layer is formed by physical vapor deposition; In the second film formation step, the second electrode layer is formed by plating. 4. A method for manufacturing a semiconductor device according to claim 1. (Appendix 5) the first electrode layer and the second electrode layer are made of the same material; 5. A method for manufacturing a semiconductor device according to claim 1. (Appendix 6) A first bonding step of bonding a support substrate to the device surface of the base material with an adhesive prior to the first film forming step. 6. A method for manufacturing a semiconductor device according to any one of claims 1 to 5. (Appendix 7) After the film-formed member removing step, a support substrate removing step of removing the support substrate from the base material; a singulation step of singulating the base material; having 7. A method for manufacturing the semiconductor device according to claim 6.

[0053] Although some embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope of the invention and its equivalents described in the claims, as well as in the scope and spirit of the invention. [Explanation of symbols]

[0054] 1...semiconductor device, 10...substrate, 10a...device surface, 10b...back surface of substrate, 12...circuit portion, 25...adhesive, 31...first electrode layer, 32...second electrode layer, 40...film-formed member, 42...intermediate layer, 50...dicing tape, S02...first attachment step, S04...first film-formation step, S05, S205...second film-formation step, S06...bonding step, S07, S207...film-formed member removal step, S09...support substrate removal step, S10...single step

Claims

1. a first film formation step of forming a first electrode layer on a back surface of the substrate, the back surface facing the opposite side to a device surface on which a circuit portion is formed, among the outer surfaces of the substrate; a second film-forming step of forming a second electrode layer on a surface of the film-forming member; a bonding step of bonding the first electrode layer and the second electrode layer; and removing the film-formed member from the second electrode layer. A method for manufacturing a semiconductor device.

2. In the second film-forming step, the second electrode layer is formed on the surface of the film-forming member via an intermediate layer containing aluminum atoms, In the film-formed member removing step, after immersing at least the intermediate layer in water, the film-formed member is removed from the second electrode layer. The method for manufacturing a semiconductor device according to claim 1 .

3. The temperature of the water is 50° C. or more and 100° C. or less. The method for manufacturing a semiconductor device according to claim 2 .

4. In the first film formation step, the first electrode layer is formed by physical vapor deposition, In the second film formation step, the second electrode layer is formed by plating. The method for manufacturing a semiconductor device according to claim 1 .

5. a material constituting the first electrode layer and a material constituting the second electrode layer are the same material; The method for manufacturing a semiconductor device according to claim 1 .

6. a first bonding step of bonding a support substrate to the device surface of the base material with an adhesive prior to the first film forming step; The method for manufacturing a semiconductor device according to claim 1 .

7. After the film-formed member removing step, a support substrate removing step of removing the support substrate from the base material; a singulation step of singulating the base material; having The method for manufacturing a semiconductor device according to claim 6 .

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