JP7645827B2 - Method for manufacturing semiconductor device - Google Patents

Description

This disclosure relates to a method for manufacturing a semiconductor device.

Patent Document 1 discloses a method for manufacturing a semiconductor device that includes a process for cutting the semiconductor wafer from the rear surface of the semiconductor wafer, a reinforcing member fixing process for fixing a reinforcing member made of a framed dicing tape to the rear surface of the semiconductor wafer, and a process for plating the semiconductor wafer while supporting the semiconductor wafer via the reinforcing member.

Patent No. 4333650

In conventional technology, it was difficult to adequately protect the back surface of a semiconductor wafer during plating after ribs were formed on the wafer.

The present disclosure is intended to solve these problems, and aims 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.

In one aspect, the method for manufacturing a semiconductor device disclosed herein includes the steps of partially removing a second main surface side of a semiconductor wafer having a first main surface and a second main surface, forming a rib on the second main surface of the semiconductor wafer 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 an outer periphery of the semiconductor wafer, cutting the semiconductor wafer in the thickness direction of the semiconductor wafer inside, in a plan view, an area 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, plating the first main surface of the semiconductor wafer with the first tape attached to the second main surface of the semiconductor wafer, attaching a second tape to an area of the second main surface of the semiconductor wafer where the rib is not formed before cutting the semiconductor wafer, cutting the semiconductor wafer with the second tape attached to the area of the second main surface of the semiconductor wafer where the rib is not formed, and attaching the first tape to the second main surface of the semiconductor wafer via the second tape .

This 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.

2 is a flowchart of a method for manufacturing a semiconductor device according to the first embodiment. 1A to 1C are diagrams showing a state during manufacturing in the manufacturing method of a semiconductor device according to a first embodiment; 1A to 1C are diagrams showing a state during manufacturing in the manufacturing method of a semiconductor device according to a first embodiment; 1A to 1C are diagrams showing a state during manufacturing in the manufacturing method of a semiconductor device according to a first embodiment; 1A to 1C are diagrams showing a state during manufacturing in the manufacturing method of a semiconductor device according to a first embodiment; 1A to 1C are diagrams showing a state during manufacturing in the manufacturing method of a semiconductor device according to a first embodiment; 1A to 1C are diagrams showing a state during manufacturing in the manufacturing method of a semiconductor device according to a first embodiment; 1A to 1C are diagrams showing a state during manufacturing in the manufacturing method of a semiconductor device according to a first embodiment; 1A to 1C are diagrams showing a state during manufacturing in the manufacturing method of a semiconductor device according to a first embodiment; 1A to 1C are diagrams showing a state during manufacturing in the manufacturing method of a semiconductor device according to a first embodiment; 11A to 11C are diagrams showing a state during manufacturing in a modified example of the manufacturing method of the semiconductor device according to 11A to 11C are diagrams showing a state during manufacturing in a modified example of the manufacturing method of the semiconductor device according to 1A to 1C are diagrams showing a state during manufacturing in the manufacturing method of a semiconductor device according to a first embodiment; 1A to 1C are diagrams showing a state during manufacturing in the manufacturing method of a semiconductor device according to a first embodiment; 13A to 13C are diagrams showing a state during manufacturing in a manufacturing method of a semiconductor device according to a second embodiment; 13A to 13C are diagrams showing a state during manufacturing in a manufacturing method of a semiconductor device according to a second embodiment; 13A to 13C are diagrams showing a state during manufacturing in a manufacturing method of a semiconductor device according to a third embodiment; 13A to 13C are diagrams showing a state during manufacturing in a manufacturing method of a semiconductor device according to a third embodiment;

<A. First embodiment>
Fig. 1 is a flow chart of the method for manufacturing a semiconductor device according to the present embodiment. Fig. 2 to Fig. 10 each show a schematic cross-sectional view of a semiconductor wafer in the method for manufacturing a semiconductor device according to the present embodiment.

In the method for manufacturing a semiconductor device according to the present embodiment, first, in step S1, as shown in FIG. 2, 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. The semiconductor wafer 1 is, for example, a wafer of a Si semiconductor, a SiC semiconductor, or a GaN semiconductor.

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.

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 may be, for example, aluminum (Al) or aluminum with added silicon (AlSi). When AlSi is used as the electrode material, aluminum spikes are suppressed.

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

Next, in step S3, while supporting the semiconductor wafer 1 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 thinner (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, a rib 10 is formed on the back surface 1b of the semiconductor wafer 1, which is convex from the front surface 1a toward the back surface 1b along the outer periphery of the semiconductor wafer 1.

In a semiconductor wafer 1 having ribs 10, the ribs 10 act as reinforcing members, so even if the central portion of the semiconductor wafer 1 in a plan view is ground and thinned, the strength of the semiconductor wafer 1 is not reduced.

The thickness of the central portion of the semiconductor wafer 1 in a planar view after step S3 is adjusted based on the withstand voltage of the semiconductor device being manufactured. The thickness of the central portion of the semiconductor wafer 1 in a planar view after step S3 is, for example, 60 μm to 200 μm.

Next, in the back side structure formation process of step S4, as shown in FIG. 5, a back side structure region 4 is formed on the back side 1b of the semiconductor wafer 1. In forming the back side 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 side structure region 4 has an electrode, and the electrode is, for example, an electrode in which aluminum, titanium, and nickel are stacked.

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 plan view from the area where the rib 10 is formed, to separate the peripheral portion of the semiconductor wafer 1 from the central portion of the semiconductor wafer 1, and the rib 10 is removed from the semiconductor wafer 1.

If 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 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 will be narrowed. 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 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 this embodiment, these problems can be avoided by performing step S5.

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.

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

Prior to step S5, the protective tape 3 may be peeled off from the semiconductor wafer 1, a different tape may be attached to the front surface 1a of the semiconductor wafer 1, and the semiconductor wafer 1 may be supported via the different tape before step S5 is performed. Compared to the case where the protective tape 3 is peeled off from the semiconductor wafer 1 and the different tape is attached to the front surface 1a of the semiconductor wafer 1, the cost of peeling off the protective tape 3 and attaching the different tape can be reduced by cutting the semiconductor wafer 1 with the protective tape 3 still attached.

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

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 from the back surface 1b to the front surface 1a of the semiconductor wafer 1. When cutting the semiconductor wafer 1 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, a decrease in the degree of adhesion between the tape 6 (see FIG. 7 and FIG. 14) and the semiconductor wafer 1 due to the burrs 9 or dross can be avoided in the mounting process of step S6 described later.

Next, in the mounting process of step S6, as shown in FIG. 7, 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.

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 coating on the surface. The ring frame 5 is also, for example, a ring frame made of a resin-based material.

The tape 6 is, for example, an adhesive tape with an adhesive on the side to be attached to the semiconductor wafer 1. In step S5, the ribs 10 are removed from the semiconductor wafer 1, and the back surface 1b of the semiconductor wafer 1 is highly flat, so that the semiconductor wafer 1 and the tape 6 are firmly attached to each other, and gaps are unlikely to form 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 the plating solution. In addition, because gaps are unlikely to form 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 processes after step S8.

The adhesive of the tape 6 is, for example, an adhesive that is resistant to acidic or alkaline plating solutions and is responsive to ultraviolet light.

Next, in the protective tape peeling process of step S7, as shown in FIG. 8, the protective tape 3 is peeled off from the front surface 1a of the semiconductor wafer 1. 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 prior to the ring cutting process of step S5, if necessary.

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 that 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.

The nickel plating film is formed to a thickness of, for example, 2 to 8 μm to improve the reliability of chip mounting in subsequent processes.

In the plating process of step S8, as shown in FIG. 9, 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 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.

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

After step S8 is completed, step S9 may be performed with tape 6 still attached to semiconductor wafer 1. In other words, 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.

As described above, in the manufacturing method of the semiconductor device of this embodiment, the back surface 1b side of the semiconductor wafer 1 is partially removed to form the rib 10 that is convex in one direction from the front surface 1a to the back surface 1b 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 on the inner side in a plan view from the area where the rib 10 is formed to remove the rib 10 from the semiconductor wafer 1, and after the rib 10 is removed from the semiconductor wafer 1, the tape 6 is attached to the back surface 1b of the semiconductor wafer 1, and the front surface 1a of the semiconductor wafer 1 is plated with the tape 6 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.

When cutting the semiconductor wafer 1 to remove the ribs 10 from the semiconductor wafer 1, the semiconductor wafer 1 is cut from the back surface 1b toward the front surface 1a, thereby preventing a decrease in the degree of adhesion between the back surface 1b of the semiconductor wafer 1 and the tape 6 due to burrs or dross generated during the cutting process.

After processing the front surface 1a of the semiconductor wafer 1 in step S1, protective tape 3 is applied to the front surface 1a of the semiconductor wafer 1, and with the protective tape 3 applied to the front surface 1a of the semiconductor wafer 1, ribs 10 are formed in step S3 and the ribs are removed in step S5, thereby preventing damage to the semiconductor wafer 1.

After forming the ribs 10 in step S3, by processing the back surface 1b of the semiconductor wafer 1 in step S4 before removing the ribs 10 in step S5, damage to the semiconductor wafer 1 in step S4 can be suppressed.

<A-1. Modified Examples>
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.

In addition, before the ring cutting process in step S5, the back surface protective tape 8 may be attached to a selective area of the back surface 1b of the part thinned in step S3, that is, the area of the back surface 1b other than the rib 10, and in step S5, the area of the semiconductor wafer 1 where the rib 10 is not formed on the back surface 1b and where the back surface protective tape 8 is not attached to the back surface 1b may be cut. In this case, the back surface protective tape 8 is attached to the inside of the rib 10 with a gap required for dicing between the back surface protective tape 8 and the rib 10. As shown in FIG. 12, the semiconductor wafer 1 is cut in an area that is inside the rib 10 and outside the area where the back surface protective tape 8 is attached, and where the back surface protective tape 8 is not 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 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 during ring cutting, and contamination of the back surface 1b of the semiconductor wafer 1 with the plating solution in step S8 is suppressed.

After the back surface protective tape 8 is applied to the back surface 1b of the semiconductor wafer 1 at a location other than the rib 10, if the tape 6 supported by the ring frame 5 is applied 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 applied is protected in step S8. However, in this case, there is a problem that the plating solution that has entered the gap between the semiconductor wafer 1 and the tape 6 causes contamination of the semiconductor wafer 1 or the semiconductor manufacturing equipment in the process after step S8. As in this modified example, such a problem can be suppressed by performing step S5 after applying the back surface protective tape 8 to the back surface 1b of the semiconductor wafer 1, and then applying 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.

<B. Second embodiment>
This embodiment differs from the semiconductor device manufacturing method of the first embodiment in that in the back grinding process of step S3, ribs 11 or 12 are formed instead of ribs 10. Also, in this embodiment, step S5 is not performed, that is, ribs 11 or 12 are not removed from semiconductor wafer 1, and tape 6 supported by ring frame 5 is attached to back surface 1b of semiconductor wafer 1 in step S6. The semiconductor device manufacturing method of this embodiment is otherwise similar to that of the first embodiment.

Ribs 11 and 12 are formed on the back surface 1b of semiconductor wafer 1 so as to be convex along the outer periphery of semiconductor wafer 1 in the direction from front surface 1a to back surface 1b.

In this embodiment, the inner peripheral surface 11b (see FIG. 15) or the inner peripheral surface 12b (see FIG. 16) of the rib 11 formed in step S3 has an inclination that is positioned further outward in the X-direction. Here, the X-direction side refers to the direction from the front surface 1a toward the back surface 1b in the thickness direction of the semiconductor wafer 1.

When ribs 11 are formed on the semiconductor wafer 1, in step S6, tape 6 is applied to the inner circumferential surface 11b of the rib 11 and the area of the back surface 1b of the semiconductor wafer 1 where the ribs 11 are not provided. When ribs 12 are formed on the semiconductor wafer 1, in step S6, tape 6 is applied to the inner circumferential surface 12b of the rib 12 and the area of the back surface 1b of the semiconductor wafer 1 where the ribs 12 are not provided. By having the inner circumferential surface 11b of the rib 11 or the inner circumferential surface 12b of the rib 12 inclined so as to be positioned further outward in the X-direction, the tape 6 can easily follow the shape of the back surface 1b of the semiconductor wafer 1, and the degree of adhesion between the back surface 1b of the semiconductor wafer 1 and the tape 6 is increased. As a result, the back surface 1b of the semiconductor wafer 1 is better protected in the plating process of step S8.

As shown in FIG. 15, there is a bend 11c between the inner surface 11b of the rib 11 and an area of the back surface 1b of the semiconductor wafer 1 where the rib 11 is not formed. To allow 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.

As shown in FIG. 16, the inner peripheral surface 12b of the rib 12 has a concave curved shape in a direction perpendicular to the circumferential direction in a plan view of the semiconductor wafer 1. The large radius of curvature of the concave curved shape increases the degree of adhesion between the back surface 1b of the semiconductor wafer 1 and the tape 6, making it less likely that a gap will form between the back surface 1b of the semiconductor wafer 1 and the tape 6. This provides better protection for the back surface 1b of the semiconductor wafer 1 in the plating process of step S8. The radius of curvature of the concave curved shape is, for example, equal to or greater than the height H of the rib 12.

There is no bending between the inner circumferential surface 12b of the rib 12 and the area of the back surface 1b of the semiconductor wafer 1 where the rib 12 is not formed, and the inner circumferential surface 12b of the rib 12 and the area of the back surface 1b of the semiconductor wafer 1 where the rib 12 is not formed are smoothly connected, which increases the degree of adhesion between the back surface 1b of the semiconductor wafer 1 and the tape 6.

By forming the ribs 10 in step S3 and removing the ribs in step S5 while the protective tape 3 is attached to the front surface 1a of the semiconductor wafer 1, damage to the semiconductor wafer 1 can be suppressed.

<B-1. Modified Examples>
Instead of forming rib 11 or rib 12 in the back grinding step of step S3, rib 10 may be formed in the back grinding step of step S3 as in the first embodiment, and after processing the back surface 1b side of semiconductor wafer 1 in the back surface side structure forming step of step S4, the inner peripheral surface side of rib 10 may be partially removed to form rib 11 or rib 12 which is the portion of rib 10 that was not removed. In this case, the strength of semiconductor wafer 1 can be maintained higher when processing the back surface 1b side of semiconductor wafer 1 in step S4.

<C. Third embodiment>
The method for manufacturing a semiconductor device according to the present embodiment differs from the method for manufacturing a semiconductor device according to the second embodiment in that in step S6, tape 6 is processed to provide a partially thin region on tape 6 before tape 6 is attached to semiconductor wafer 1. In other respects, the method for manufacturing a semiconductor device according to the present embodiment is similar to the method for manufacturing a semiconductor device according to the second embodiment. The following description will be given assuming that the rib provided on semiconductor wafer 1 is rib 11, but the same applies when the rib provided on semiconductor wafer 1 is rib 12.

In step S6 of this embodiment, before the tape 6 is applied to the inner circumferential surface 11b of the rib 11 and the area of the back surface 1b of the semiconductor wafer 1 where the rib 11 is not provided, the tape 6 is processed to provide a partially thin area so that the tape 6 can follow the shape of the inner circumferential surface 11b of the rib 11 and the area of the back surface 1b of the semiconductor wafer 1 where the rib 11 is not provided. For example, the tape 6 is processed to partially thin the tape 6 along the area where the tape 6 is applied to the rib 11.

For example, cuts 6a are made in the tape 6 along the areas to be attached to the ribs 11, and then the tape 6 is attached to the inner surface 11b of the ribs 11 and to areas of the back surface 1b of the semiconductor wafer 1 where the ribs 11 are not provided (see FIG. 17).

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

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 on the tape 6 that corresponds to the outer periphery of the semiconductor wafer 1. This makes it easier for the tape 6 to conform to the shape of the ribs 11 of the semiconductor wafer 1, making it less likely for gaps to form between the tape 6 and the semiconductor wafer 1, and providing better protection for the back surface 1b of the semiconductor wafer 1 in the plating process of step S8.

By pulling the tape 6, which has a partially thin area, in the in-plane direction, and attaching the tape 6 to the area on the back surface 1b of the semiconductor wafer 1 where the ribs 11 are not provided and to the inner surface 11b of the ribs 11, it is possible to make it less likely that gaps will occur between the semiconductor wafer 1 and the tape 6.

As the tape 6 can more easily follow the shape of the ribs 11 of the semiconductor wafer 1, there are fewer restrictions on the shape of the ribs 11, and the shape of the ribs 11 can be made to better maintain the rigidity of the semiconductor wafer 1. For example, the angle θ of the bend 11c between the inner surface 11b of the ribs 11 and the area of the back surface 1b of the semiconductor wafer 1 where the ribs 11 are not formed can be made larger.

The embodiments can be freely combined, modified, or omitted as appropriate.

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 (18)

a semiconductor wafer having a first main surface and a second main surface, the second main surface side of the semiconductor wafer being partially removed to form a rib 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 toward the second main surface in a thickness direction of the semiconductor wafer;
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;
applying a first tape to the second main surface of the semiconductor wafer after the ribs have been removed from 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. 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. 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. 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 rib is 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 rib is 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. 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 on the first main surface side of the semiconductor wafer is performed;
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. 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. 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. 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. 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;
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. 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. 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;
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. 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;
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. 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;
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. 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;
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. 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;
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. 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 on the first main surface side of the semiconductor wafer is performed;
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. 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. 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 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 on 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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