Semiconductor device manufacturing method

Abstract

To provide a manufacturing method of a semiconductor device which can protect a back surface of a semiconductor wafer in a plating treatment after a rib is formed on the semiconductor wafer.SOLUTION: A manufacturing method of a semiconductor device comprises the steps of: forming a rib being convex in one direction heading to a second principal surface from a first principal surface in the thickness direction of a semiconductor wafer along the outer periphery of the semiconductor wafer on the second principal surface of the semiconductor wafer by partially removing the second principal surface side of the semiconductor wafer having the first principal surface and the second principal surface; removing the rib from the semiconductor wafer by cutting the semiconductor wafer in the thickness direction of the semiconductor wafer on the inner side in the plan view with respect to the region where the rib is formed; attaching the first tape to the second principal surface of the semiconductor wafer after the rib is removed from the semiconductor wafer; and performing plating on the first principal surface of the semiconductor wafer in such a state that a first tape is attached to the second principal surface of the semiconductor wafer.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a method for manufacturing a semiconductor device. [Background technology]

[0002] Patent Document 1 discloses a method for manufacturing a semiconductor device, which includes a step of cutting the semiconductor wafer from the back surface of the semiconductor wafer, a reinforcing member fixing step of fixing a reinforcing member made of a framed dicing tape to the back surface of the semiconductor wafer, and a step of plating the semiconductor wafer while supporting the semiconductor wafer via the reinforcing member. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 4333650 Summary of the Invention [Problem to be solved by the invention]

[0004] In the conventional technology, it has been difficult to adequately protect the back surface of a semiconductor wafer during plating treatment after ribs are formed on the wafer.

[0005] The present disclosure is intended to solve such problems, and has an object to provide a method for manufacturing a semiconductor device that can protect the back surface of a semiconductor wafer during plating processing after ribs are formed on the semiconductor wafer. [Means for solving the problem]

[0006] In one aspect, a method for manufacturing a semiconductor device according to the present disclosure includes partially removing a second main surface side of a semiconductor wafer having a first main surface and a second main surface, forming a rib that is convex in one direction from the first main surface to the second main surface in the thickness direction of the semiconductor wafer along the outer periphery of the semiconductor wafer on the second main surface of the semiconductor wafer, cutting the semiconductor wafer in the thickness direction of the semiconductor wafer on the inner side in a plan view from the region where the rib is formed to remove the rib from the semiconductor wafer, attaching a first tape to the second main surface of the semiconductor wafer after the rib has been removed from the semiconductor wafer, and plating the first main surface of the semiconductor wafer with the first tape attached to the second main surface of the semiconductor wafer. stomach , Prior to cutting the semiconductor wafer, a second tape is attached to an area of ​​the second main surface of the semiconductor wafer where the ribs are not formed, and the semiconductor wafer is cut with the second tape attached to the area of ​​the second main surface of the semiconductor wafer where the ribs are not formed, and in attaching the first tape to the second main surface of the semiconductor wafer, the first tape is attached to the second main surface of the semiconductor wafer via the second tape. A method for manufacturing a semiconductor device. Effect of the Invention

[0007] The present disclosure provides a method for manufacturing a semiconductor device that can protect the back surface of a semiconductor wafer during plating processing after ribs are formed on the semiconductor wafer. [Brief description of the drawings]

[0008] [Figure 1] 3 is a flowchart of a method for manufacturing the semiconductor device according to the first embodiment. [Diagram 2] 1A to 1C are diagrams illustrating a state during manufacturing in the manufacturing method of the semiconductor device according to the first embodiment. [Diagram 3] 1A to 1C are diagrams illustrating a state during manufacturing in the manufacturing method of the semiconductor device according to the first embodiment. [Figure 4] 1A to 1C are diagrams illustrating a state during manufacturing in the manufacturing method of the semiconductor device according to the first embodiment. [Diagram 5] 1A to 1C are diagrams illustrating a state during manufacturing in the manufacturing method of the semiconductor device according to the first embodiment. [Figure 6] 1A to 1C are diagrams illustrating a state during manufacturing in the manufacturing method of the semiconductor device according to the first embodiment. [Figure 7]It is a diagram showing a state during the manufacturing process of the semiconductor device of Embodiment 1. [Figure 8] It is a diagram showing a state during the manufacturing process of the semiconductor device of Embodiment 1. [Figure 9] It is a diagram showing a state during the manufacturing process of the semiconductor device of Embodiment 1. [Figure 10] It is a diagram showing a state during the manufacturing process of the semiconductor device of Embodiment 1. [Figure 11] It is a diagram showing a state during the manufacturing process of a modification of the manufacturing method of the semiconductor device of Embodiment 1. [Figure 12] It is a diagram showing a state during the manufacturing process of a modification of the manufacturing method of the semiconductor device of Embodiment 1. [Figure 13] It is a diagram showing a state during the manufacturing process of the semiconductor device of Embodiment 1. [Figure 14] It is a diagram showing a state during the manufacturing process of the semiconductor device of Embodiment 1. [Figure 15] It is a diagram showing a state during the manufacturing process of the semiconductor device of Embodiment 2. [Figure 16] It is a diagram showing a state during the manufacturing process of the semiconductor device of Embodiment 2. [Figure 17] It is a diagram showing a state during the manufacturing process of the semiconductor device of Embodiment 3. [Figure 18] It is a diagram showing a state during the manufacturing process of the semiconductor device of Embodiment 3.

Embodiments for Carrying Out the Invention

[0009] <A. Embodiment 1> FIG. 1 is a flowchart of the manufacturing method of the semiconductor device of the present embodiment. FIGS. 2 to 10 respectively show schematic cross-sectional views of a semiconductor wafer in the manufacturing method of the semiconductor device of the present embodiment.

[0010] In the method for manufacturing a semiconductor device according to the present embodiment, first, in step S1, a pattern region 2 is formed on the front surface 1a side of a semiconductor wafer 1 having a front surface 1a which is one main surface and a back surface 1b which is the other main surface, as shown in Fig. 2. The semiconductor wafer 1 is, for example, a wafer of a Si semiconductor, a SiC semiconductor, or a GaN semiconductor.

[0011] The pattern region 2 is a region having, for example, a base region, an emitter region, a gate oxide film, a gate electrode, an emitter electrode, etc., and is a region in which the structure on the front surface 1a side of the semiconductor device manufactured by the semiconductor device manufacturing method of this embodiment is formed.

[0012] The material of the electrodes in the pattern region 2 may be any material that allows plating to be performed on the surface of the electrodes in the plating process in step S8 described below. For example, when a nickel film is to be deposited in plating, the material of the electrodes in the pattern region 2 may be any material that allows a nickel film to be deposited on the surface of the electrodes. The material of the electrodes in the pattern region 2 is, for example, aluminum (Al) or aluminum with added silicon (AlSi). When AlSi is used as the electrode material, aluminum spikes are suppressed.

[0013] Next, in a protective tape application process of step S2, as shown in Fig. 3, a protective tape 3 for protecting the pattern region 2 is applied to the front surface 1a of the semiconductor wafer 1. This protects the pattern region 2 in a later process. The adhesive of the protective tape 3 is, for example, an ultraviolet-responsive adhesive. If the adhesive of the protective tape 3 is an ultraviolet-responsive adhesive, the amount of adhesive remaining on the front surface 1a of the semiconductor wafer 1 can be reduced when the protective tape 3 is peeled off from the front surface 1a of the semiconductor wafer 1 in step S7 described below.

[0014] Next, in step S3, while the semiconductor wafer 1 is supported via the protective tape 3, the semiconductor wafer 1 is ground from the back surface 1b side, and the back surface 1b side of the semiconductor wafer 1 is partially removed. In step S3, the central portion of the semiconductor wafer 1 in a plan view is ground and made thin (see FIG. 4). In step S3, the outer periphery of the semiconductor wafer 1 is left thicker than the central portion of the semiconductor wafer 1. As a result, ribs 10 are formed on the back surface 1b of the semiconductor wafer 1 along the outer periphery of the semiconductor wafer 1, which are convex from the front surface 1a toward the back surface 1b.

[0015] In a semiconductor wafer 1 having ribs 10, ribs 10 act as reinforcing members, so that even if the central portion of semiconductor wafer 1 in plan view is ground and thinned, a decrease in strength of semiconductor wafer 1 is suppressed.

[0016] The thickness of the central portion of the semiconductor wafer 1 in plan view after step S3 is adjusted based on the withstand voltage of the semiconductor device to be manufactured, etc. The thickness of the central portion of the semiconductor wafer 1 in plan view after step S3 is, for example, 60 μm to 200 μm.

[0017] Next, in the back surface side structure forming process of step S4, as shown in FIG. 5, a back surface structure region 4 is formed on the back surface 1b side of the semiconductor wafer 1. In forming the back surface structure region 4, for example, an ion implantation process, a laser annealing process, and a deposition process for forming an electrode are performed. The ion implantation process and the laser annealing process are for forming an impurity diffusion layer. The deposition process for forming the electrode is, for example, sputtering. The back surface structure region 4 has an electrode, and the electrode is, for example, an electrode in which aluminum, titanium, and nickel are stacked.

[0018] Next, in the ring cutting process of step S5, as shown in FIG. 6, the semiconductor wafer 1 is cut in the thickness direction of the semiconductor wafer 1 on the inner side in a planar view from the area where the ribs 10 are formed, thereby dividing the outer periphery of the semiconductor wafer 1 and the central part of the semiconductor wafer 1, and removing the ribs 10 from the semiconductor wafer 1.

[0019] When the tape 6 (see FIG. 7) is attached to the back surface 1b of the semiconductor wafer 1 in step S6 described later without performing step S5, if the tape 6 cannot follow the bend between the inner circumferential surface of the rib 10 and the area of ​​the back surface 1b of the semiconductor wafer 1 where the rib 10 is not provided, the adhesion area between the rib 10 and the tape 6 becomes narrow. In the plating process of step S8 described later, the tape 6 expands and contracts due to heat applied to the tape 6, and the adhesion between the rib 10 and the tape 6 cannot be maintained, and the rib 10 and the tape 6 are peeled off. As a result, the back surface 1b of the semiconductor wafer 1 is contaminated with the plating solution in step S8. In addition, the plating solution that has entered the gap between the tape 6 and the back surface 1b contaminates the semiconductor wafer 1 or the semiconductor manufacturing equipment in the process after step S8. In the manufacturing method of the semiconductor device of the present embodiment, these problems can be avoided by performing step S5.

[0020] In step S5, the semiconductor wafer 1 is cut with the protective tape 3 still attached, thereby preventing the semiconductor wafer 1 from cracking or chipping during cutting.

[0021] Before step S5, the protective tape 3 may be peeled off from the semiconductor wafer 1, and then step S5 may be performed.

[0022] Before step S5, the protective tape 3 may be peeled off from the semiconductor wafer 1 and another tape may be attached to the front surface 1a of the semiconductor wafer 1, and then step S5 may be performed by supporting the semiconductor wafer 1 via the other tape. Compared to the case where the protective tape 3 is peeled off from the semiconductor wafer 1 and the other tape is attached to the front surface 1a of the semiconductor wafer 1, by cutting the semiconductor wafer 1 with the protective tape 3 still attached, the cost of peeling off the protective tape 3 and attaching the other tape can be reduced.

[0023] The ring cut process in step S5 may be performed by blade dicing or laser dicing. When the semiconductor wafer 1 is cut with the protective tape 3 attached, the protective tape 3 may not be suitable for supporting the semiconductor wafer 1 when performing the blade dicing. Even in such a case, the semiconductor wafer 1 can be cut by laser dicing.

[0024] When cutting the semiconductor wafer 1 in step S5, the semiconductor wafer 1 may be cut from the front surface 1a to the back surface 1b of the semiconductor wafer 1, or may be cut from the back surface 1b to the front surface 1a of the semiconductor wafer 1. When the semiconductor wafer 1 is cut from the back surface 1b to the front surface 1a as shown in Fig. 13, burrs 9 or dross are generated on the front surface 1a side. If the burrs 9 or dross are generated on the front surface 1a side, it is possible to avoid a decrease in the degree of adhesion between the tape 6 (see Figs. 7 and 14) and the semiconductor wafer 1 due to the burrs 9 or dross in the mounting process in step S6 described later.

[0025] Next, in a mounting process of step S6, a tape 6 supported by a ring frame 5 is attached to the back surface 1b of the semiconductor wafer 1, and the semiconductor wafer 1 is mounted on the tape 6, as shown in FIG.

[0026] The ring frame 5 is an annular frame. It is preferable that the ring frame 5 does not or is unlikely to react with the plating solution in the plating process in step S8 described below. The ring frame 5 is, for example, a ring frame made of metal and processed to form a passivation film on the surface. The ring frame 5 is, for example, a ring frame made of a resin-based material.

[0027] The tape 6 is, for example, an adhesive tape having an adhesive on the side to be attached to the semiconductor wafer 1. Since the rib 10 has been removed from the semiconductor wafer 1 in step S5 and the back surface 1b of the semiconductor wafer 1 has a high flatness, the semiconductor wafer 1 and the tape 6 are firmly attached to each other, and a gap is unlikely to be formed between the semiconductor wafer 1 and the tape 6. Therefore, the tape 6 can effectively protect the back surface 1b of the semiconductor wafer 1, and for example, in the plating process of step S8 described later, the back surface 1b of the semiconductor wafer 1 can be prevented from being contaminated by a plating solution. In addition, since a gap is unlikely to be formed between the tape 6 and the back surface 1b, the plating solution that has entered the gap between the tape 6 and the back surface 1b can be prevented from contaminating the semiconductor wafer 1 or semiconductor manufacturing equipment in the process after step S8.

[0028] The adhesive of the tape 6 is, for example, an adhesive that is resistant to an acidic or alkaline plating solution and has ultraviolet light responsiveness.

[0029] Next, in the protective tape peeling process of step S7, the protective tape 3 is peeled off from the front surface 1a of the semiconductor wafer 1, as shown in Fig. 8. If the adhesive of the protective tape 3 is an ultraviolet responsive adhesive, the protective tape 3 is irradiated with ultraviolet light to reduce the adhesive strength of the protective tape 3, and then the protective tape 3 is peeled off. As described above, the protective tape 3 may be peeled off from the semiconductor wafer 1 before the ring cutting process of step S5, if necessary.

[0030] Next, in the plating process of step S8, as shown in FIG. 9, a plating film 7 is formed on the front surface 1a of the semiconductor wafer 1. In step S8, the semiconductor wafer 1 fixed to the tape 6 is immersed in a plating solution to form the plating film 7. At this time, the rear surface 1b of the semiconductor wafer 1 is protected by the tape 6, and contamination of the rear surface structure region 4 with the plating solution is significantly suppressed. The plating film 7 is, for example, a film in which a nickel plating film and a gold plating film are laminated. In this case, the nickel plating film and the gold plating film are formed at a temperature of, for example, about 80°C.

[0031] The nickel plating film is formed to a thickness of, for example, 2 to 8 μm in order to improve the reliability of chip mounting in a later process.

[0032] 9, in the plating process of step S8, a plating film 7 is formed on the electrodes of the pattern region 2. The plating film 7 may be formed on the entire pattern region 2, or may be formed on selective regions of the pattern region 2. The plating film 7 may also be formed on the entire front surface 1a of the semiconductor wafer 1.

[0033] Next, in a dicing process of step S9, the semiconductor wafer 1 is diced. As a result, a semiconductor chip 100 is obtained, which is an example of a semiconductor device manufactured by the semiconductor device manufacturing method of the present embodiment, as shown in Fig. 10. The semiconductor chip 100 is, for example, any one of a diode, a MOSFET (Metal Oxide Semiconductor Field Effect Transistor), an IGBT (Insulated Gate Bipolar Transistor), or an RC-IGBT (Reverse-Conducting IGBT).

[0034] After step S8 is completed, step S9 may be performed with tape 6 still attached to semiconductor wafer 1. That is, tape 6 may be used as a dicing tape in the dicing process of step S9. By performing step S9 with tape 6 still attached to semiconductor wafer 1, manufacturing efficiency can be improved.

[0035] As described above, in the method for manufacturing a semiconductor device according to the present embodiment, by partially removing the back surface 1b side of the semiconductor wafer 1, a rib 10 that protrudes in one direction from the front surface 1a toward the back surface 1b in the thickness direction of the semiconductor wafer 1 is formed along the outer periphery of the semiconductor wafer 1 on the back surface 1b of the semiconductor wafer 1. The semiconductor wafer 1 is cut in the thickness direction of the semiconductor wafer 1 inside in a plan view rather than the region where the rib 10 is formed to remove the rib 10 from the semiconductor wafer 1. After the rib 10 is removed from the semiconductor wafer 1, a tape 6 is attached to the back surface 1b of the semiconductor wafer 1, and plating is performed on the front surface 1a of the semiconductor wafer 1 in a state where the tape 6 is attached to the back surface 1b of the semiconductor wafer 1. By removing the rib 10 from the semiconductor wafer 1 and then attaching the tape 6 to the back surface 1b of the semiconductor wafer 1, the back surface 1b of the semiconductor wafer 1 can be protected in the plating process after the rib 10 is formed on the semiconductor wafer 1.

[0036] When cutting the semiconductor wafer 1 to remove the rib 10 from the semiconductor wafer 1, by cutting the semiconductor wafer 1 from the back surface 1b toward the front surface 1a, a decrease in the adhesion between the back surface 1b of the semiconductor wafer 1 and the tape 6 due to burrs or dross generated in the cutting can be suppressed.

[0037] After processing the front surface 1a side of the semiconductor wafer 1 in step S1, a protective tape 3 is attached to the front surface 1a of the semiconductor wafer 1. In a state where the protective tape 3 is attached to the front surface 1a of the semiconductor wafer 1, by forming the rib 10 in step S3 and removing the rib in step S5, breakage of the semiconductor wafer 1 can be suppressed.

[0038] After forming the rib 10 in step S3 and before removing the rib 10 in step S5, by processing the back surface 1b side of the semiconductor wafer 1 in step S4, breakage of the semiconductor wafer 1 in step S4 can be suppressed.

[0039] <A-1. Modification Example> Before the ring cutting process of step S5, the back surface protective tape 8 may be attached to the back surface 1b of the part thinned in step S3, that is, the back surface 1b at a location other than the rib 10. In this case, in the ring cutting process of step S5, as shown in FIG. 11, the semiconductor wafer 1 is cut in a region where the rib 10 is not formed on the back surface 1b of the semiconductor wafer 1 and where the back surface protective tape 8 is attached to the back surface 1b, with the protective tape 3 attached to the front surface 1a and the back surface protective tape 8 attached to the back surface 1b. After the semiconductor wafer 1 is ring cut with the back surface protective tape 8 attached to the back surface 1b, the tape 6 is attached to the back surface 1b of the semiconductor wafer 1 via the back surface protective tape 8. By attaching the back surface protective tape 8 to the back surface 1b before cutting the semiconductor wafer 1, even if a burr is generated on the back surface 1b side when the semiconductor wafer 1 is cut, the adhesion between the back surface protective tape 8 and the semiconductor wafer 1 at the burr portion is maintained, so that the plating solution can be prevented from penetrating between the back surface 1b of the semiconductor wafer 1 and the back surface protective tape 8 from the burr portion.

[0040] Also, before the ring cutting process in step S5, the back surface protection tape 8 may be attached to a selective region of the back surface 1b of the part thinned in step S3, that is, the portion of the back surface 1b other than the rib 10, and in step S5, the region of the semiconductor wafer 1 where the rib 10 is not formed on the back surface 1b and where the back surface protection tape 8 is not attached to the back surface 1b may be cut. In this case, the back surface protection tape 8 is attached to the inside of the rib 10 with a gap required for dicing between the back surface protection tape 8 and the rib 10. As shown in FIG. 12, the semiconductor wafer 1 is cut in a region on the inside of the rib 10, outside the region where the back surface protection tape 8 is attached, and where the back surface protection tape 8 is not attached to the back surface 1b. After the semiconductor wafer 1 is ring cut with the back surface protection tape 8 attached to the back surface 1b, the tape 6 is attached to the back surface 1b of the semiconductor wafer 1 via the back surface protection tape 8. By cutting the semiconductor wafer 1 in an area where the back surface protective tape 8 is not attached to the back surface 1b, the back surface protective tape 8 can protect the back surface 1b of the semiconductor wafer 1 without being affected by burrs or dross generated during ring cutting, and contamination of the back surface 1b of the semiconductor wafer 1 with the plating solution in step S8 is suppressed.

[0041] If the back surface protective tape 8 is attached to the back surface 1b of the semiconductor wafer 1 except for the rib 10 and the tape 6 supported by the ring frame 5 is attached to the back surface 1b of the semiconductor wafer 1 via the back surface protective tape 8 without performing step S5, the area of ​​the back surface 1b of the semiconductor wafer 1 to which the back surface protective tape 8 is attached is protected in step S8. However, in this case, there is a problem that the semiconductor wafer 1 or the semiconductor manufacturing equipment is contaminated in the process after step S8 due to the plating solution that has entered the gap between the semiconductor wafer 1 and the tape 6. As in this modified example, such a problem can be suppressed by performing step S5 after attaching the back surface protective tape 8 to the back surface 1b of the semiconductor wafer 1, and then attaching the back surface 1b of the semiconductor wafer 1 to the tape 6 supported by the ring frame 5 via the back surface protective tape 8.

[0042] <B. Embodiment 2> Compared with the method for manufacturing a semiconductor device according to Embodiment 1, this embodiment is different in that in the back grinding step of Step S3, rib 11 or rib 12 is formed instead of rib 10. Also, in this embodiment, Step S5 is not performed, that is, without removing rib 11 or rib 12 from semiconductor wafer 1, in Step S6, tape 6 supported by ring frame 5 is attached to the back surface 1b of semiconductor wafer 1. The method for manufacturing a semiconductor device according to this embodiment is the same as the method for manufacturing a semiconductor device according to Embodiment 1 in other respects.

[0043] Rib 11 and rib 12 are ribs formed on the back surface 1b of semiconductor wafer 1 along the outer periphery of semiconductor wafer 1 and convex in the direction from the front surface 1a toward the back surface 1b.

[0044] The inner peripheral surface 11b (see FIG. 15) or inner peripheral surface 12b (see FIG. 16) of rib 11 formed in Step S3 of this embodiment has an inclination such that it is located more outward on the X-direction side. Here, the X-direction side represents the direction from the front surface 1a toward the back surface 1b in the thickness direction of semiconductor wafer 1.

[0045] When rib 11 is formed on semiconductor wafer 1, in Step S6, tape 6 is attached to the region where rib 11 is not provided among the inner peripheral surface 11b of rib 11 and the back surface 1b of semiconductor wafer 1. When rib 12 is formed on semiconductor wafer 1, in Step S6, tape 6 is attached to the region where rib 12 is not provided among the inner peripheral surface 12b of rib 12 and the back surface 1b of semiconductor wafer 1. Since the inner peripheral surface 11b of rib 11 or the inner peripheral surface 12b of rib 12 has an inclination such that it is located more outward on the X-direction side, tape 6 can more easily follow the shape of the back surface 1b of semiconductor wafer 1, and the degree of adhesion between the back surface 1b of semiconductor wafer 1 and tape 6 is increased. Thereby, in the plating step of Step S8, the back surface 1b of semiconductor wafer 1 is better protected.

[0046] As shown in FIG. 15, there is a bend 11c between the inner peripheral surface 11b of the rib 11 and the region on the back surface 1b of the semiconductor wafer 1 where the rib 11 is not formed. In order for the tape 6 to easily follow the shape of the back surface 1b of the semiconductor wafer 1, it is preferable that the angle θ of the bend 11c is small. For example, the angle θ of the bend 11c is 30 degrees or less. The angle θ is, for example, 5 degrees or more and 30 degrees or less.

[0047] As shown in FIG. 16, the inner peripheral surface 12b of the rib 12 has a concave curved shape with respect to the direction orthogonal to the circumferential direction in the plan view of the semiconductor wafer 1. By having a large radius of curvature of the concave curved shape, the degree of adhesion between the back surface 1b of the semiconductor wafer 1 and the tape 6 increases, and it becomes difficult to form a gap between the back surface 1b of the semiconductor wafer 1 and the tape 6. Thereby, in the plating step of step S8, the back surface 1b of the semiconductor wafer 1 is better protected. The radius of curvature of the concave curved shape is, for example, equal to or greater than the height H of the rib 12.

[0048] There is no bend between the inner peripheral surface 12b of the rib 12 and the region on the back surface 1b of the semiconductor wafer 1 where the rib 12 is not formed, and the inner peripheral surface 12b of the rib 12 and the region on the back surface 1b of the semiconductor wafer 1 where the rib 12 is not formed are smoothly connected, so that the degree of adhesion between the back surface 1b of the semiconductor wafer 1 and the tape 6 becomes higher.

[0049] By forming the rib 10 in step S3 and removing the rib in step S5 with the protective tape 3 attached to the front surface 1a of the semiconductor wafer 1, breakage of the semiconductor wafer 1 can be suppressed.

[0050] <B-1. Modification Example> Instead of forming rib 11 or rib 12 in the back grinding step of step S3, rib 10 is formed in the back grinding step of step S3 in the same manner as in Embodiment 1. After processing the back surface 1b side of the semiconductor wafer 1 in the back surface side structure forming step of step S4, rib 11 or rib 12, which is the portion of rib 10 that is not removed, may be formed by partially removing the inner peripheral surface side of rib 10. In this case, the strength of the semiconductor wafer 1 can be kept higher when processing the back surface 1b side of the semiconductor wafer 1 in step S4.

[0051] <C. Embodiment 3> The method for manufacturing a semiconductor device according to the present embodiment is different from the method for manufacturing a semiconductor device according to Embodiment 2 in that, in step S6, before attaching the tape 6 to the semiconductor wafer 1, the tape 6 is processed to provide a partially thin region on the tape 6. The method for manufacturing a semiconductor device according to the present embodiment is the same as the method for manufacturing a semiconductor device according to Embodiment 2 in other respects. Hereinafter, a case where the rib provided on the semiconductor wafer 1 is rib 11 will be assumed for description, but the same applies when the rib provided on the semiconductor wafer 1 is rib 12.

[0052] In step S6 of the present embodiment, before attaching the tape 6 to the inner peripheral surface 11b of rib 11 and the region of the back surface 1b of the semiconductor wafer 1 where rib 11 is not provided, the tape 6 is processed to provide a partially thin region on the tape 6 so that the tape 6 can follow the shape of the region of the inner peripheral surface 11b of rib 11 and the region of the back surface 1b of the semiconductor wafer 1 where rib 11 is not provided. For example, the tape 6 is processed to partially thin the tape 6 along the region to be attached to rib 11.

[0053] For example, after making a cut 6a in the tape 6 along the region to be attached to rib 11, the tape 6 is attached to the inner peripheral surface 11b of rib 11 and the region of the back surface 1b of the semiconductor wafer 1 where rib 11 is not provided (see FIG. 17).

[0054] For example, tape 6 is cut along the area to be attached to rib 11 to form groove 6b, and then tape 6 is attached to the inner surface 11b of rib 11 and the area of ​​the back surface 1b of semiconductor wafer 1 where rib 11 is not provided (see Figure 18).

[0055] The notches 6a or grooves 6b are provided, for example, in an annular region of the tape 6 that is about 1 to 3 mm inward from a position corresponding to the outer periphery of the semiconductor wafer 1. This allows the tape 6 to easily follow the shape of the ribs 11 of the semiconductor wafer 1, making it difficult for gaps to form between the tape 6 and the semiconductor wafer 1, and thus better protecting the back surface 1b of the semiconductor wafer 1 in the plating process in step S8.

[0056] By pulling the tape 6 having partially thin regions in an in-plane direction and attaching the tape 6 to the regions on the back surface 1b of the semiconductor wafer 1 where the ribs 11 are not provided and to the inner surfaces 11b of the ribs 11, it is possible to make it more difficult for gaps to occur between the semiconductor wafer 1 and the tape 6.

[0057] Since the tape 6 can easily follow the shape of the rib 11 of the semiconductor wafer 1, restrictions on the shape of the rib 11 are reduced, and the shape of the rib 11 can be made to be one that can more easily maintain the rigidity of the semiconductor wafer 1. For example, the angle θ of the bend 11c between the inner peripheral surface 11b of the rib 11 and a region of the back surface 1b of the semiconductor wafer 1 where the rib 11 is not formed can be made larger.

[0058] It should be noted that the embodiments can be freely combined, and each embodiment can be modified or omitted as appropriate. [Explanation of symbols]

[0059] 1 semiconductor wafer, 1a front surface, 1b back surface, 2 pattern area, 3 protective tape, 4 back surface structure area, 5 ring frame, 6 tape, 6a notch, 6b groove, 7 plating film, 8 back surface protective tape, 9 burrs, 10, 11 rib, 11b inner surface, 11c bend, 12 rib, 12b inner surface, 100 semiconductor chip.

Claims

1. a rib is formed on the second main surface of the semiconductor wafer along an outer periphery of the semiconductor wafer, the rib being convex in one direction from the first main surface to the second main surface in a thickness direction of the semiconductor wafer, by partially removing the second main surface side of the semiconductor wafer having a first main surface and a second main surface; cutting the semiconductor wafer in a thickness direction of the semiconductor wafer on the inner side in a plan view from a region in which the ribs are formed, thereby removing the ribs from the semiconductor wafer; after the ribs are removed from the semiconductor wafer, applying a first tape to the second main surface of the semiconductor wafer; With the first tape attached to the second main surface of the semiconductor wafer, plating is performed on the first main surface of the semiconductor wafer; before the cutting of the semiconductor wafer, a second tape is attached to an area of ​​the second main surface of the semiconductor wafer where the ribs are not formed; cutting the semiconductor wafer in a state where the second tape is attached to the area of ​​the second main surface of the semiconductor wafer where the ribs are not formed; In the bonding of the first tape to the second main surface of the semiconductor wafer, the first tape is bonded to the second main surface of the semiconductor wafer via the second tape. A method for manufacturing a semiconductor device.

2. 2. The method of manufacturing a semiconductor device according to claim 1, In the cutting of the semiconductor wafer, the semiconductor wafer is cut from the second main surface toward the first main surface. A method for manufacturing a semiconductor device.

3. 3. The method for manufacturing a semiconductor device according to claim 1, further comprising the steps of: In the cutting of the semiconductor wafer, a region of the semiconductor wafer where the ribs are not formed on the second main surface and where the second tape is attached to the second main surface is cut. A method for manufacturing a semiconductor device.

4. 3. The method for manufacturing a semiconductor device according to claim 1, further comprising the steps of: the joining of the second tape to the region of the second main surface of the semiconductor wafer where the ribs are not formed is joining of the second tape to a selective region of the region of the second main surface of the semiconductor wafer where the ribs are not formed, In the cutting of the semiconductor wafer, a region of the semiconductor wafer where the ribs are not formed on the second main surface and where the second tape is not attached to the second main surface is cut. A method for manufacturing a semiconductor device.

5. 5. A method for manufacturing a semiconductor device according to claim 1, comprising the steps of: Processing the first main surface side of the semiconductor wafer; a third tape is attached to the first main surface of the semiconductor wafer after the processing is performed on the first main surface side of the semiconductor wafer; forming the rib and removing the rib with the third tape attached to the first main surface of the semiconductor wafer; A method for manufacturing a semiconductor device.

6. 6. A method for manufacturing a semiconductor device according to claim 1, comprising the steps of: after the formation of the rib and before the removal of the rib, processing is performed on the second main surface side of the semiconductor wafer; A method for manufacturing a semiconductor device.

7. 7. A method for manufacturing a semiconductor device according to claim 1, comprising the steps of: The first tape is a tape supported by an annular frame. A method for manufacturing a semiconductor device.

8. a first rib that is convex in one direction from the first main surface to the second main surface in a thickness direction of the semiconductor wafer along an outer periphery of the semiconductor wafer is formed on the second main surface of the semiconductor wafer by partially removing the second main surface side of the semiconductor wafer having a first main surface and a second main surface; The inner circumferential surface of the first rib is located further outward in the one direction, a first tape is attached to the inner peripheral surface of the first rib and to an area of ​​the second main surface of the semiconductor wafer where the first rib is not provided; plating the first main surface of the semiconductor wafer while the first tape is attached to the inner peripheral surface of the first rib and to an area of ​​the second main surface of the semiconductor wafer where the first rib is not provided; the first tape being a tape supported by an annular frame; a bend is formed between the inner peripheral surface of the first rib and a region of the second main surface of the semiconductor wafer where the first rib is not formed, and the angle of the bend is 30 degrees or less; A method for manufacturing a semiconductor device.

9. By partially removing the second main surface side of a semiconductor wafer having a first main surface and a second main surface, a first rib is formed on the second main surface of the semiconductor wafer along the outer periphery of the semiconductor wafer, the first rib being convex in one direction in the thickness direction of the semiconductor wafer from the first main surface toward the second main surface, The inner circumferential surface of the first rib is located further outward in the one direction, a first tape is attached to the inner peripheral surface of the first rib and to an area of ​​the second main surface of the semiconductor wafer where the first rib is not provided; plating the first main surface of the semiconductor wafer while the first tape is attached to the inner peripheral surface of the first rib and to an area of ​​the second main surface of the semiconductor wafer where the first rib is not provided; the first tape being a tape supported by an annular frame; the inner peripheral surface of the first rib has a concave curved shape in a direction perpendicular to the circumferential direction of the semiconductor wafer; A method for manufacturing a semiconductor device.

10. 10. The method of manufacturing a semiconductor device according to claim 9, a radius of curvature of the concave curved shape of the inner peripheral surface of the first rib in a direction perpendicular to the circumferential direction of the semiconductor wafer is equal to or greater than a height of the first rib; A method for manufacturing a semiconductor device.

11. By partially removing the second main surface side of a semiconductor wafer having a first main surface and a second main surface, a first rib is formed on the second main surface of the semiconductor wafer along the outer periphery of the semiconductor wafer, the first rib being convex in one direction in the thickness direction of the semiconductor wafer from the first main surface toward the second main surface; The inner circumferential surface of the first rib is located further outward in the one direction, a first tape is attached to the inner peripheral surface of the first rib and to an area of ​​the second main surface of the semiconductor wafer where the first rib is not provided; plating the first main surface of the semiconductor wafer while the first tape is attached to the inner peripheral surface of the first rib and to an area of ​​the second main surface of the semiconductor wafer where the first rib is not provided; the first tape being a tape supported by an annular frame; There is no bending between an inner peripheral surface of the first rib and a region of the second main surface of the semiconductor wafer where the first rib is not formed, and the inner peripheral surface of the first rib and the region of the second main surface of the semiconductor wafer where the first rib is not formed are smoothly connected. A method for manufacturing a semiconductor device.

12. By partially removing the second main surface side of a semiconductor wafer having a first main surface and a second main surface, a first rib is formed on the second main surface of the semiconductor wafer along the outer periphery of the semiconductor wafer, the first rib being convex in one direction in the thickness direction of the semiconductor wafer from the first main surface toward the second main surface, The inner circumferential surface of the first rib is located further outward in the one direction, a first tape is attached to the inner peripheral surface of the first rib and to an area of ​​the second main surface of the semiconductor wafer where the first rib is not provided; plating the first main surface of the semiconductor wafer while the first tape is attached to the inner peripheral surface of the first rib and to an area of ​​the second main surface of the semiconductor wafer where the first rib is not provided; the first tape being a tape supported by an annular frame; before attaching the first tape to the inner peripheral surface of the first rib and to the region of the second main surface of the semiconductor wafer where the first rib is not provided, the first tape is processed to provide a partially thin region in the first tape so that the first tape can conform to the shape of the inner peripheral surface of the first rib and to the shape of the region of the second main surface of the semiconductor wafer where the first rib is not provided; A method for manufacturing a semiconductor device.

13. By partially removing the second main surface side of a semiconductor wafer having a first main surface and a second main surface, a first rib is formed on the second main surface of the semiconductor wafer along the outer periphery of the semiconductor wafer, the first rib being convex in one direction in the thickness direction of the semiconductor wafer from the first main surface toward the second main surface; The inner circumferential surface of the first rib is located further outward in the one direction, a first tape is attached to the inner peripheral surface of the first rib and to an area of ​​the second main surface of the semiconductor wafer where the first rib is not provided; plating the first main surface of the semiconductor wafer while the first tape is attached to the inner peripheral surface of the first rib and to an area of ​​the second main surface of the semiconductor wafer where the first rib is not provided; the first tape being a tape supported by an annular frame; before attaching the first tape to the inner peripheral surface of the first rib and to an area of ​​the second main surface of the semiconductor wafer where the first rib is not provided, the first tape is processed to partially thin the first tape along the area to be attached to the first rib; A method for manufacturing a semiconductor device.

14. By partially removing the second main surface side of a semiconductor wafer having a first main surface and a second main surface, a first rib is formed on the second main surface of the semiconductor wafer along the outer periphery of the semiconductor wafer, the first rib being convex in one direction in the thickness direction of the semiconductor wafer from the first main surface toward the second main surface, The inner circumferential surface of the first rib is located further outward in the one direction, a first tape is attached to the inner peripheral surface of the first rib and to an area of ​​the second main surface of the semiconductor wafer where the first rib is not provided; plating the first main surface of the semiconductor wafer while the first tape is attached to the inner peripheral surface of the first rib and to an area of ​​the second main surface of the semiconductor wafer where the first rib is not provided; the first tape being a tape supported by an annular frame; before attaching the first tape to the inner peripheral surface of the first rib and to an area of ​​the second main surface of the semiconductor wafer where the first rib is not provided, making a cut in the first tape along the area to be attached to the first rib or cutting the first tape along the area to be attached to the first rib; A method for manufacturing a semiconductor device.

15. By partially removing the second main surface side of a semiconductor wafer having a first main surface and a second main surface, a first rib is formed on the second main surface of the semiconductor wafer along the outer periphery of the semiconductor wafer, the first rib being convex in one direction in the thickness direction of the semiconductor wafer from the first main surface toward the second main surface; The inner circumferential surface of the first rib is located further outward in the one direction, a first tape is attached to the inner peripheral surface of the first rib and to an area of ​​the second main surface of the semiconductor wafer where the first rib is not provided; plating the first main surface of the semiconductor wafer while the first tape is attached to the inner peripheral surface of the first rib and to an area of ​​the second main surface of the semiconductor wafer where the first rib is not provided; the first tape being a tape supported by an annular frame; while pulling the first tape in an in-plane direction, attaching the first tape to an inner peripheral surface of the first rib and to an area of ​​the second main surface of the semiconductor wafer where the first rib is not provided; A method for manufacturing a semiconductor device.

16. 16. A method for manufacturing a semiconductor device according to claim 8, comprising the steps of: Processing the first main surface side of the semiconductor wafer; a third tape is attached to the first main surface of the semiconductor wafer after the processing is performed on the first main surface side of the semiconductor wafer; forming the first rib with the third tape attached to the first main surface of the semiconductor wafer; A method for manufacturing a semiconductor device.

17. 17. A method for manufacturing a semiconductor device according to claim 8, comprising the steps of: After the first rib is formed, the second main surface of the semiconductor wafer is processed. A method for manufacturing a semiconductor device.

18. By partially removing the second main surface side of a semiconductor wafer having a first main surface and a second main surface, a first rib is formed on the second main surface of the semiconductor wafer along the outer periphery of the semiconductor wafer, the first rib being convex in one direction in the thickness direction of the semiconductor wafer from the first main surface toward the second main surface, The inner circumferential surface of the first rib is located further outward in the one direction, a first tape is attached to the inner peripheral surface of the first rib and to an area of ​​the second main surface of the semiconductor wafer where the first rib is not provided; plating the first main surface of the semiconductor wafer while the first tape is attached to the inner peripheral surface of the first rib and to an area of ​​the second main surface of the semiconductor wafer where the first rib is not provided; the first tape being a tape supported by an annular frame; a second rib that is convex in the one direction along an outer periphery of the semiconductor wafer is formed on the second main surface of the semiconductor wafer by partially removing the second main surface side of the semiconductor wafer; After the formation of the second rib, processing is performed on the second main surface side of the semiconductor wafer; After the processing of the second main surface side of the semiconductor wafer is performed, an inner peripheral surface side of the second rib is partially removed to form the first rib, which is a portion of the second rib that has not been removed. A method for manufacturing a semiconductor device.

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