Method for manufacturing semiconductor device

Abstract

A method of manufacturing a semiconductor device according to this embodiment includes a first film formation step of forming a first electrode layer on a base material rear surface facing a side opposite a device surface on the outer surfaces of the base material on which a circuit part is formed. The method includes a second film formation step of forming a second electrode layer on a surface of a film formation target member. The method includes a joining step of joining the first electrode layer and the second electrode layer. The method includes a film formation target member removal step for removing the film formation target member from the second electrode layer.

Description

Semiconductor device manufacturing method

[0001] This application claims priority to Japanese Patent Application No. 2023-124034, filed on July 31, 2023, the contents of which are incorporated herein by reference.

[0002] In semiconductor devices, the thickness of the substrate is sometimes reduced to improve the characteristics of the semiconductor device. Furthermore, in semiconductor devices, the amount of heat generated by the circuit portion formed on the substrate tends to increase. As a result, the temperature of the semiconductor device tends to rise, 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.

[0003] JP 2014-17333 A

[0004] The problem to be solved by the present invention is to provide a semiconductor device that can operate stably.

[0005] The method for manufacturing a semiconductor device according to the 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-forming member, a bonding step of bonding the first electrode layer and the second electrode layer, and a film-forming member removal step of removing the film-forming member from the second electrode layer.

[0006] 1 is a schematic cross-sectional view showing a semiconductor device according to a first embodiment; a flowchart showing a manufacturing method for a semiconductor device according to the first embodiment; a schematic cross-sectional view showing a device surface forming step according to the first embodiment; a schematic cross-sectional view showing a first bonding step according to the first embodiment; a schematic cross-sectional view showing a first film forming step according to the first embodiment; a schematic cross-sectional view showing a second film forming step according to the first embodiment; a schematic cross-sectional view showing a bonding step according to the first embodiment; a schematic cross-sectional view showing a film formation member removing step according to the first embodiment; a schematic cross-sectional view showing a second bonding step according to the first embodiment; a first schematic cross-sectional view showing a support substrate removing step according to the first embodiment; a second schematic cross-sectional view showing a support substrate removing step according to the first embodiment; a first schematic cross-sectional view showing a singulation step according to the first embodiment; a second schematic cross-sectional view showing the singulation step according to the first embodiment; a flowchart showing a manufacturing method for a semiconductor device according to a second embodiment; a schematic cross-sectional view showing a second film forming step according to the second embodiment; a schematic cross-sectional view showing a film formation member removing step according to the second embodiment.

[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 "up-down direction." Note that the terms "upper side," "lower side," and "up-down direction" do not 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] 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 unit 12, a front electrode unit 15, and a back electrode unit 30.

[0010] The semiconductor chip 10T is made of a semiconductor material. In this embodiment, examples of the semiconductor material that can be used to form the semiconductor chip 10T include, but are not limited to, silicon (Si), silicon carbide (SiC), gallium arsenide (GaAs), and gallium nitride (GaN).

[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 a plurality of devices, such as semiconductor elements constituting MOSFETs, and circuit patterns that electrically connect the devices.

[0012] The surface electrode portion 15 is formed on the surface 12a of the circuit portion 12. For example, if 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 an electrically conductive material. Examples of materials that can be used to form 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, if the semiconductor device 1 is a MOSFET, the back electrode unit 30 is the drain electrode of the MOSFET. The back electrode unit 30 includes an electrically conductive material. Materials that can be used for the back electrode unit 30 include, but are not limited to, metals such as copper, aluminum, nickel, silver, and gold, and alloys containing at least one of these metals. 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 bonded 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 approximately 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 manufacturing method of the semiconductor device 1 of this embodiment. The manufacturing method of 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-forming 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 equipment, etc., who perform the work in each step. The work in each step may be performed by workers alone, by assembly equipment alone, or by both workers and assembly equipment.

[0016] As shown in FIG. 3 , the device surface forming step S01 is a step of forming a circuit portion 12 and a surface electrode portion 15 on the device surface 10a of the substrate 10. First, an operator forms a plurality of circuit portions 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 upward on the outer surface of the substrate 10. The circuit portions 12 are formed spaced apart from one another. The plurality of circuit portions 12 are formed side by side in the left-right direction of FIG. 3 . Although not shown, the plurality of circuit portions 12 may also be formed side by side in a direction perpendicular to the plane of FIG. 3 . In this case, the circuit portions 12 are arranged side by side in both the left-right direction of FIG. 3 and the direction perpendicular to the plane of FIG. 3 . In the following description, in the steps prior to the grinding step S03, the surface of the outer surface of the substrate 10 facing opposite the device surface 10a is the initial back surface 10f.

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

[0018] As shown in Fig. 4, the first attaching 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 attaching step S02 is a step prior to the first film-forming step S04. An operator first applies uncured adhesive 25 to the device surface 10a. The adhesive 25 is also applied to the surface of each surface electrode portion 15, between the surface electrode portions 15, and between the circuit portions 12. For example, an acrylic adhesive, an epoxy adhesive, or a silicone adhesive can be used as the adhesive 25.

[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 together via 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 and bonds 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 thinning the thickness of the substrate 10 by grinding the lower portion of the substrate 10 to form a substrate back surface 10b. The worker 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. Furthermore, by grinding the lower portion of the substrate 10, the substrate back surface 10b of the substrate 10 is formed. The substrate back surface 10b is the surface facing downward among the outer surfaces of the substrate 10. The substrate back surface 10b is the surface facing opposite to the device surface 10a. When the substrate back surface 10b is formed, the grinding step S03 ends.

[0021] The first film-forming step S04 is a step of forming a first electrode layer 31 on the rear surface 10b of the substrate 10. The first film-forming step S04 is performed while the substrate 10 is supported on 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 to a uniform thickness over the entire rear surface 10b of the substrate. The thickness of the first electrode layer 31 is, for example, approximately 1 μm. The thickness of the first electrode layer 31 may be smaller than 1 μm or larger than 1 μm. Once the first electrode layer 31 is formed on the rear surface 10b of the substrate, the first film-forming step S04 is completed. Although not shown in the drawings, in this embodiment, the first electrode layer 31 is formed on the rear surface 10b of the substrate via a laminated film made of, for example, titanium (Ti) and copper, which can prevent copper constituting the first electrode layer 31 from diffusing into the substrate 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-forming member 40. In this embodiment, the film-forming member 40 is made of a semiconductor material. Examples of semiconductor materials that can be used to form the film-forming member 40 include, but are not limited to, silicon, silicon carbide, gallium arsenide, and gallium nitride. The film-forming member 40 may also be made of other materials, such as metal. In this embodiment, the film-forming member 40 is disk-shaped. The film-forming member 40 may also have 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-forming member 40. The intermediate layer 42 is made of aluminum and alumina (Al ２ O ３ In the present embodiment, the intermediate layer 42 is made of alumina.

[0023] Next, a worker 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-forming 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) composed 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. In the film-forming member removing step S07, the laminated film may be removed as needed to expose the second electrode layer 32 after removing the film-forming member 40 from the second electrode layer 32. The thickness of the second electrode layer 32 is preferably in the range of 10 μm to 50 μm. In this embodiment, the thickness of the second electrode layer 32 is approximately 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 portion 30. The bonding step S06 is performed in a vacuum inside a chamber (not shown). As shown in FIG. 6 , an operator moves the film-forming member 40, with the surface 40a facing upward, from the lower side of the substrate 10 to the upper side, and presses the film-forming member 40 against the substrate 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 operator 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. In other words, 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 portion 30 is formed. When the back electrode portion 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 a support substrate 20 is attached to the device surface 10a of the substrate 10 using an 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, vertical deformation of the thinned substrate 10 can be suppressed in the first film-forming step S04. Therefore, the thickness of the first electrode layer 31 formed on the substrate back surface 10b can be made more uniform in the first film-forming step S04, thereby suppressing variations in the bonding strength between the first electrode layer 31 and the second electrode layer 32. This increases the strength of the back electrode portion 30.

[0026] As shown in FIG. 8 , the film-forming member removal step S07 is a step of removing the film-forming member 40 from the second electrode layer 32. First, an operator immerses at least the intermediate layer 42 in water stored in a bathtub (not shown). When the intermediate layer 42 is immersed in water, water penetrates into the interface between the intermediate layer 42 and the second electrode layer 32. This reduces the bonding strength between the intermediate layer 42 and the second electrode layer 32. This is believed to be due to the following phenomenon. First, the intermediate layer 42 containing aluminum atoms undergoes a hydration reaction with the penetrated water, causing alumina hydrate crystals to grow on the surface 42 a of the intermediate layer 42. Therefore, the surface roughness of the surface 42 a of the intermediate layer 42 increases, thereby reducing the contact area between the surface 42 a of the intermediate layer 42 and the back surface 32 b of the second electrode layer 32. This reduces the bonding strength between the intermediate layer 42 and the second electrode layer 32. The intermediate layer 42 and the film-forming member 40 may be immersed in the water, or the portion from the support substrate 20 to the second electrode layer 32 in addition to the intermediate layer 42 and the film-forming member 40 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 relative to the one jig. As described above, because the bonding strength between the intermediate layer 42 and the second electrode layer 32 is reduced, the worker can peel the intermediate layer 42 from the second electrode layer 32 by moving the other jig downward relative 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 removal 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-forming member removal step S07, as described above, the intermediate layer 42 is immersed in water, thereby reducing the bond strength between the intermediate layer 42 and the second electrode layer 32. This allows the intermediate layer 42 to be easily peeled off from the second electrode layer 32. This allows the film-forming member 40 to be easily removed from the second electrode layer 32. For example, if a mixed acid solution such as nitric acid and hydrofluoric acid is penetrated into the intermediate layer 42 to deteriorate the intermediate layer 42 and reduce the bond strength between the intermediate layer 42 and the second electrode layer 32, the adhesive 25 may be deteriorated if the mixed acid solution adheres to the adhesive 25. This may reduce the adhesive strength between the support substrate 20 and the base material 10. In contrast, in this embodiment, the bond strength between the intermediate layer 42 and the second electrode layer 32 is reduced by water, so the adhesive 25 does not deteriorate even if water adheres to the adhesive 25. Therefore, this embodiment can prevent 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 prevents the mixed acid solution from adhering to the circuit portion 12 and the surface electrode portion 15, thereby preventing deterioration of the circuit portion 12 and the surface electrode portion 15. This prevents a decrease in the yield of the semiconductor device 1 and improves the operational stability 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 higher and 100°C or lower. Therefore, according to this embodiment, the reaction between the intermediate layer 42 and water can be favorably promoted. Therefore, the bonding strength between the intermediate layer 42 and the second electrode layer 32 can be stably reduced, making it easy to remove the film-forming member 40 from the second electrode layer 32. The water temperature is preferably high, preferably close to 100°C. The film-forming member removing step S07 ends when the film-forming member 40 is removed from the second electrode layer 32. The method for removing the film-forming member 40 from the second electrode layer 32 in the film-forming member removing step S07 is not limited to the method described in this embodiment. For example, the film-forming member 40 may be removed from the second electrode layer 32 by grinding the film-forming member 40. In this case, the intermediate layer 42 may be removed from the second electrode layer 32 by grinding the intermediate layer 42.

[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 secures the individual semiconductor chips 10T when the base material 10 is diced in the singulation step S10, which will be described later. The dicing tape 50 is attached to the back surface 32b of the second electrode layer 32. In other words, 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, thereby suppressing deterioration of the adhesive 25. This suppresses a decrease in the adhesive strength 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, making it possible to easily attach the dicing tape 50 to the back surface 30b of the back surface electrode portion 30. This suppresses an increase in the number of steps required for 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 attaching step S02, in which a support substrate 20 is attached to the device surface 10a of the substrate 10 using an adhesive 25, prior to 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, the shape and position of the substrate 10 in the vertical direction can be stabilized in each of the steps subsequent to the first film-forming step S04, namely, the bonding step S06, the film-forming member removal step S07, and the second attaching step S08. Therefore, the first electrode layer 31 and the second electrode layer 32 can be easily bonded in the bonding step S06. Furthermore, the film-forming member 40 can be easily removed from the second electrode layer 32 in the film-forming member removal step S07. Furthermore, the dicing tape 50 can be easily attached to the back surface 30b of the back electrode portion 30 in the second attaching step S08. Therefore, the operations of the bonding step S06, the film formation member removing step S07, and the second attaching step S08 can be simplified, and an increase in the number of steps for manufacturing the semiconductor substrate 1 can be suppressed.

[0034] The support substrate removal step S09 is a step of removing the support substrate 20 from the base material 10. As shown in FIG. 2 , the support substrate removal step S09 is a step performed after the film-forming member removal 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 disposed above the support substrate 20. As described above, since the support substrate 20 is translucent, the laser beam L passes through the support substrate 20 and is irradiated onto the release layer 22. As described above, since the release layer 22 is black, the release layer 22 absorbs the laser beam L. This increases the temperature of the release layer 22, causing it to separate from the support substrate 20. Thereafter, the adhesive 25 may be removed by peeling it off with adhesive tape or by dissolving it in a solvent.

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

[0036] In the support substrate removal step S09, the support substrate 20 may be removed from the substrate 10 after a solvent has penetrated the adhesive 25 to deteriorate the adhesive 25 and reduce the adhesive strength between the adhesive 25 and the substrate 10 and the surface electrode portion 15. Alternatively, the support substrate 20 may be removed from the substrate 10 by inserting a sharp tool between the substrate 10 and the support substrate 20 and peeling the adhesive 25 from the substrate 10. In the support substrate removal step S09, after removing the support substrate 20 from the substrate 10, it is preferable to adhere tape (not shown) to the device surface 10a and the surface electrode portion 15 and then peel off the tape to remove the adhesive 25 remaining on the device surface 10a and the surface electrode portion 15. This allows, for example, stable electrical connection between the surface electrode portion 15 and an external electrode (not shown) connected to the surface electrode portion 15 during use of the semiconductor device 1. This improves the operational stability of the semiconductor device 1.

[0037] According to this embodiment, the manufacturing method of the semiconductor device 1 includes a support substrate removing step S09, which removes the support substrate 20 from the base material 10 after the film-forming member removing step S07. Therefore, in the film-forming member removing step S07, the base material 10 can be supported by the support substrate 20. As described above, by holding the support substrate 20 with one jig or the like while moving the film-forming member 40 downward with the other jig or the like, the intermediate layer 42 can be easily peeled off from the second electrode layer 32. This simplifies the process of removing the film-forming member 40 from the second electrode layer 32, thereby preventing an increase in the number of steps in the film-forming member removing step S07.

[0038] As shown in FIG. 12 , the singulation process S10 is a process for singulating the substrate 10. The worker or the like singulates the substrate 10 and divides it into multiple semiconductor chips 10T by cutting the substrate 10 and the back electrode portion 30. In this embodiment, the worker or the like cuts the substrate 10 and the back electrode portion 30 using a dicing device 90 having a blade 91. At this time, a circuit portion 12 and a front electrode portion 15 are formed on the device surface 10a of each semiconductor chip 10T. Furthermore, a back electrode portion 30 is formed on the substrate back surface 10b of each semiconductor chip 10T. Thus, when the substrate 10 is singulated, multiple semiconductor devices 1 (see FIG. 1 ) are formed. Note that the dicing tape 50 is not cut in the singulation process 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 using a laser dicing device. When the substrate 10 is singulated, the singulation step S10 is completed.

[0039] The pick-up process S11 is a process for individually removing multiple semiconductor devices 1 fixed to the dicing tape 50 from the dicing tape 50. As shown in FIG. 13 , a worker first performs a process to weaken the adhesive strength of the adhesive layer (not shown) on the surface 50 a 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 below the dicing tape 50 using a member such as a pin (not shown), and then applies negative pressure to the device surface 10 a of the semiconductor device 1 using a removal device (not shown) to adsorb it to the removal device, thereby individually removing the semiconductor device 1 from the dicing tape 50. The pick-up process S11 is completed when all semiconductor devices 1 are removed from the dicing tape 50. As shown in FIG. 2 , when the pick-up process 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 together, and a film-forming member removal step S07 of removing the film-forming member 40 from the second electrode layer 32. Thus, the back surface electrode 30 can be formed by the bonded first electrode layer 31 and the second electrode layer 32. Therefore, the thickness of the back surface electrode 30 can be increased compared to when the back surface electrode 30 is formed by only one of the first electrode layer 31 and the second electrode layer 32. This reduces the thermal resistance of the back surface electrode 30, thereby increasing the amount of heat dissipated from the circuit unit 12 to the outside of the semiconductor device 1 via the back surface electrode 30. This prevents the temperature of the circuit unit 12 from becoming too high, thereby improving the operational stability of the semiconductor device 1.

[0041] Furthermore, according to this embodiment, as described above, the thickness of the back surface electrode portion 30 can be increased, thereby increasing the strength of the back surface electrode portion 30. Therefore, the strength of the semiconductor device 1 can be increased. This makes it possible to prevent the semiconductor device 1 from being damaged by stress applied to the semiconductor device 1 when removing the semiconductor device 1 from the dicing tape 50 in the pickup step S11. Therefore, the yield of the semiconductor device 1 can be increased. Furthermore, as described above, the strength of the semiconductor device 1 can be increased, thereby making it possible to prevent the semiconductor device 1 from being damaged by stress, such as thermal stress, applied to the semiconductor device 1 during use. Therefore, the operational stability of the semiconductor device 1 can be improved.

[0042] According to this embodiment, in the first film-forming step S04, the first electrode layer 31 is formed by physical vapor deposition, and in the second film-forming 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] Furthermore, according to this 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 separate member from the substrate 10. This prevents the chemical solution used in the plating from adhering to the circuit unit 12 and the surface electrode unit 15 formed on the device surface 10a of the substrate 10. This prevents the circuit unit 12 and the surface electrode unit 15 from being deteriorated by the chemical solution, thereby preventing a decrease in the yield of the semiconductor device 1. Furthermore, preventing the circuit unit 12 and the surface electrode unit 15 from being deteriorated improves the operational stability of the semiconductor device 1.

[0044] Furthermore, according to the present embodiment, as described above, 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 separate member from the base material 10, thereby preventing the chemical solution from adhering to the adhesive 25. This prevents the adhesive 25 from deteriorating, thereby suppressing a decrease in the adhesive strength between the support substrate 20 and the base material 10. This stabilizes the shape and position of the base material 10 in the vertical direction in each of the bonding step S06, the film-forming member removal step S07, and the second attaching step S08. Therefore, as described above, the operations in each of the bonding step S06, the film-forming member removal step S07, and the second attaching step S08 can be simplified, thereby suppressing an increase in the number of steps required to manufacture the semiconductor substrate 1.

[0045] According to this embodiment, the first electrode layer 31 and the second electrode layer 32 are made of the same material. Therefore, the bonding strength between the first electrode layer 31 and the second electrode layer 32 is easier to increase compared to when the first electrode layer 31 and the second electrode layer 32 are made of different materials. This more effectively increases the strength of the back electrode portion 30, thereby more effectively increasing the strength of the semiconductor device 1. Therefore, in the pickup step S11, 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 can be more effectively prevented. This can more effectively increase the yield of the semiconductor device 1. Furthermore, damage to the semiconductor device 1 due to stress, such as thermal stress, applied to the semiconductor device 1 during use can be more effectively prevented. This can more effectively improve the operational stability of the semiconductor device 1.

[0046] Second Embodiment FIG. 14 is a flowchart showing a method for manufacturing a semiconductor device 1 according to this embodiment. The method for manufacturing a semiconductor device 1 according to 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 S205, a bonding step S06, a film formation member removing step S207, a second bonding step S08, a support substrate removing step S09, a singulation step S10, and a pickup step S11. The operations performed in the second film forming step S205 and the film formation member removing step S207 according to this embodiment are different from the operations performed in the second film forming step S05 and the film formation member removing step S07 according to the first embodiment. The operations performed in the other steps of the method for manufacturing a semiconductor device 1 according to this embodiment are similar to the operations performed in the other steps of the method for manufacturing a semiconductor device 1 according to the first embodiment. In the following description, components identical to those in the first embodiment are designated by the same reference numerals, and their description will be omitted.

[0047] As shown in FIG. 15 , the second film formation process S205 is a process of forming a second electrode layer 32 on the surface 40a of the film formation target member 40. In this embodiment, the second electrode layer 32 is formed directly on the surface 40a of the film formation target 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 to 50 μm. In this embodiment, the thickness of the second electrode layer 32 is approximately 20 μm. The thickness of the second electrode layer 32 is thicker than the thickness of the first electrode layer 31. Once the second electrode layer 32 is formed on the surface 40a of the film formation target member 40, the second film formation process S205 is completed. Note that other configurations of the film formation target member 40 and the second electrode layer 32 of this embodiment are similar to those of the film formation target member 40 and the second electrode layer 32 of the first embodiment described above.

[0048] 16 , the film-forming member removal step S207 is a step of removing the film-forming 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-forming member 40 to remove it from the second electrode layer 32. In this embodiment, the grinding device 297 is a surface grinder that grinds the workpiece with a rotating disc-shaped grinding wheel. When the film-forming member 40 is removed from the second electrode layer 32, the film-forming member removal step S207 ends.

[0049] 16 , the back surface electrode unit 30 can be configured by a first electrode layer 31 and a second electrode layer 32 bonded to each other. Therefore, as in the first embodiment described above, the thickness of the back surface electrode unit 30 can be increased compared to when the back surface electrode unit 30 is configured by only one of the first electrode layer 31 and the second electrode layer 32. This reduces the thermal resistance of the back surface electrode unit 30, thereby increasing the amount of heat dissipated from the circuit unit 12 to the outside of the semiconductor device 1 via the back surface electrode unit 30. Therefore, the temperature of the circuit unit 12 can be prevented from becoming too high, thereby improving the operational stability 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, thereby increasing the strength of the back surface electrode portion 30. Therefore, the strength of the semiconductor device 1 can be increased. As a result, similar to the first embodiment described above, damage to the semiconductor device 1 can be suppressed in the pick-up step 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 operational stability of the semiconductor device 1 can be improved.

[0051] According to at least one of the embodiments described above, a semiconductor device capable of stable operation 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] A method for manufacturing a semiconductor device according to an embodiment includes the following additional aspects: (Supplementary Note 1) A method for manufacturing a semiconductor device, comprising: a first film formation step of forming a first electrode layer on a back surface of the substrate, the back surface facing away from a device surface on which a circuit portion is formed, of an outer surface of the substrate; a second film formation step of forming a second electrode layer on a surface of a film-forming member; a bonding step of bonding the first electrode layer and the second electrode layer; and a film-forming member removal step of removing the film-forming member from the second electrode layer. (Supplementary Note 2) The method for manufacturing a semiconductor device according to Supplementary Note 1, wherein in the second film formation step, the second electrode layer is formed on the surface of the film-forming member via an intermediate layer containing aluminum atoms; and in the film-forming member removal step, the film-forming member is removed from the second electrode layer after immersing at least the intermediate layer in water. (Supplementary Note 3) The method for manufacturing a semiconductor device according to Supplementary Note 2, wherein the temperature of the water is 50°C or higher and 100°C or lower. (Supplementary Note 4) The method for manufacturing a semiconductor device according to any one of Supplementary Notes 1 to 3, wherein in the first film formation step, the first electrode layer is formed by physical vapor deposition, and in the second film formation step, the second electrode layer is formed by plating. (Supplementary Note 5) The method for manufacturing a semiconductor device according to any one of Supplementary Notes 1 to 4, wherein a material constituting the first electrode layer and a material constituting the second electrode layer are the same material. (Supplementary Note 6) The method for manufacturing a semiconductor device according to any one of Supplementary Notes 1 to 5, comprising a first attaching step of attaching a support substrate to the device surface of the base material with an adhesive, before the first film formation step. (Supplementary Note 7) The method for manufacturing a semiconductor device according to Supplementary Note 6, comprising, after the film formation member removing step, a support substrate removing step of removing the support substrate from the base material, and a singulation step of singulating the base material.

[0053] Although several 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 within the scope and spirit of the invention, as well as within the scope of the invention described in the claims and their equivalents.

Claims

1. A method for manufacturing a semiconductor device, comprising: a first film formation process for forming a first electrode layer on the back surface of the substrate, the back surface facing away from the device surface on which a circuit portion is formed; a second film formation process for forming a second electrode layer on the surface of a member to be filmed; a bonding process for bonding the first electrode layer and the second electrode layer; and a film-formed member removal process for removing the member to be filmed from the second electrode layer.

2. The method for manufacturing a semiconductor device as described in claim 1, wherein, 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, and, in the film-forming member removal step, the film-forming member is removed from the second electrode layer after at least the intermediate layer is immersed in water.

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

4. A method for manufacturing a semiconductor device according to any one of claims 1 to 3, wherein in the first film formation step, the first electrode layer is formed by physical vapor deposition, and in the second film formation step, the second electrode layer is formed by plating.

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

6. The method for manufacturing a semiconductor device according to claim 1, further comprising a first attachment step of attaching a support substrate to the device surface of the base material with an adhesive prior to the first film formation step.

7. The method for manufacturing a semiconductor device according to claim 6, further comprising, after the film-formed member removing step, a support substrate removing step of removing the support substrate from the base material, and a singulating step of singulating the base material.

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