JP2003273052A - Back side grinding method and method of manufacturing semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a back side grinding method and a method of manufacturing a semiconductor device, where dispersion of thickness in a chip is reduced, after conducting the back grinding of a semiconductor wafer. <P>SOLUTION: The back side grinding method has the steps of forming bumps 19 on the semiconductor wafer 10 using a resist pattern 22 as a mask, adhering a protective tape 15 on the bumps and the resist pattern, performing vacuum chucking on the protective tape by a vacuum chuck cup to hold semiconductor wafer 10, and pressing the back side of the semiconductor wafer 10 held by the vacuum chuck cup against the surface of a rotating rotational grinder, to grind the back side of the semiconductor wafer. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a backside grinding method and a semiconductor device manufacturing method in which variations in thickness within a chip after backside grinding of a semiconductor wafer are reduced.

[0002]

2. Description of the Related Art A conventional method of manufacturing a semiconductor device will be described below. First, an interlayer insulating film is deposited on a silicon substrate, and an Al alloy film is deposited on this interlayer insulating film by a sputtering method. Then, by patterning this Al alloy film, an Al alloy pad and A are formed on the interlayer insulating film.
l alloy wiring is formed. Next, a passivation film is deposited on the Al alloy pad and the interlayer insulating film, and the passivation film is etched. As a result, an opening located above the Al alloy pad is formed in the passivation film, and the surface of the Al alloy pad is exposed by this opening. Then, an under bump metal film is formed by a sputtering method in the opening and on the entire surface including the passivation film.

Next, a resist pattern having an opening in a bump forming region located on the Al alloy pad is formed on the under bump metal film. Then, gold bumps are formed on the under bump metal film by metal plating using this resist pattern as a mask. Next, the resist pattern is peeled off, and the under bump metal film is etched by using the gold bump as a mask.

Through these steps, a semiconductor wafer as shown in FIG. 8 is manufactured. Note that FIG. 8 is a plan view showing a conventional semiconductor device. This semiconductor device has a plurality of product chips 112 formed on a semiconductor wafer 111. The product chip 112 is formed in the effective chip area on the wafer surface. This effective chip area is a range where good chips can be obtained. No chip is formed in the invalid chip region 110 where the area for one product chip cannot be secured in the outer peripheral portion of the wafer. The width from the outer peripheral portion of the wafer to the central portion of the wafer in the region where such chips are not formed varies depending on the size of the product chip 112, but is, for example, about 10 mm.

A plurality of gold bumps (not shown) are formed on the product chip 112 by the method described above. No bump is formed in the invalid chip region 110. Further, semiconductor chips and the like are formed on the product chip 112.

Next, a conventional backside grinding method for the bumped wafer shown in FIG. 8 will be described with reference to FIG. FIG. 9 is a partial cross-sectional view showing a state in which a protective tape that protects the front surface of the wafer is attached to the wafer when the back surface of the bumped wafer is ground.

First, a protective tape 115 is adhered to the surface of the wafer on which the gold bumps 116 are formed. At this time, a step portion 1 is formed on the outer periphery of the protective tape 115, and the step portion 1 is about 10 mm at the shortest.

Next, the suction surface of the vacuum suction disk of the back surface grinding apparatus is brought into contact with the protective tape 115, and the wafer 111 with bumps is vacuum suctioned and held on the suction surface of the vacuum suction disk.
Then, the back surface of the wafer with bumps 111 is pressed against the surface of the rotating grinding machine supported by the rotating shaft. Then
After the back surface of the wafer 111 is ground for a predetermined time in the back surface grinding device, the protective tape 115 is peeled off from the front surface of the wafer 111, and the wafer 111 is diced into semiconductor chips.

[0009]

By the way, in the above-described conventional method for manufacturing a semiconductor device, the protective tape 115 is attached to the surface of the semiconductor wafer 111 to protect the wafer surface when the back surface of the wafer is ground. However, since the gold bumps 115 are formed on the surface of the wafer, steps are present on the surface of the wafer due to the unevenness of the gold bumps 115. This step is also transferred to the surface of the protective tape after the protective tape 115 is attached, and the step becomes large especially near the outermost periphery of the wafer. If there is such a step, it is impossible to uniformly press the entire front surface of the wafer when the back surface of the wafer is ground. This may cause a relatively large variation in the grinding thickness of the back surface of the wafer.

Further, since no chip is formed in the invalid chip area other than the range where a good chip can be taken, no bump is formed in the invalid chip area. In a region where such bumps are not formed, the width from the wafer outer peripheral portion to the wafer central portion is 10 mm or more in a wide area. For this reason, when the protective tape is attached to the surface of the wafer, a step portion l of 10 mm or more is formed on the outer peripheral portion of the wafer.
If there is such a step portion l, a relatively large variation may occur in the grinding thickness of the back surface of the wafer. In that case, the inner plate thickness difference of the chip becomes large especially in the outermost chip of the wafer.

In order to reduce the unevenness of the backside grinding thickness due to the step due to the gold bumps as described above, when the protective tape is attached to the gold bumps, the state in which the adhesive material is embedded between the gold bumps can be controlled. It is conceivable to use a protective tape such as this. However, in order to control the state in which the adhesive material is embedded in this manner, it is necessary to appropriately change the protective tape depending on the height of the bump, the grinding thickness, the chip size, the shot method on the wafer during exposure, and the like. For this reason, it is inconvenient because the condition must be set as a prior confirmation, and even if the condition is set, it often becomes defective.

The present invention has been made in consideration of the above circumstances, and an object of the present invention is to provide a backside grinding method and a semiconductor in which variations in the thickness of a chip after backside grinding of a semiconductor wafer are reduced. It is to provide a method of manufacturing a device.

[0013]

In order to solve the above problems, a backside grinding method according to the present invention comprises a step of forming bumps on a semiconductor wafer using a resist pattern as a mask,
A step of attaching a protective tape on the bumps and the resist pattern, a step of holding the semiconductor wafer by vacuum suction of this protective tape with a vacuum suction disk, and a vacuum suction disk on the surface of the rotating rotary grinding machine. And a step of grinding the back surface of the held semiconductor wafer by pressing the back surface of the held semiconductor wafer.

According to the above backside grinding method, bumps are formed on a semiconductor wafer using a resist pattern as a mask, and then a protective tape is attached onto the bumps and the resist pattern without removing the resist pattern. Therefore, it is possible to reduce the level difference formed on the surface of the protective tape due to the bumps and depressions as in the prior art. Therefore, it is possible to uniformly press the entire front surface of the semiconductor wafer during the back surface grinding of the semiconductor wafer.
It is possible to improve the accuracy of grinding the back surface of the wafer. As a result, it is possible to suppress variations in the grinding thickness of the back surface of the wafer.

In the back grinding method according to the present invention, the steps of forming the bumps include the steps of forming a pad on the insulating film, forming a passivation film on the pad, and forming a passivation film on the pad. A step of forming an opening located on the pad, a step of forming an under bump metal film in the opening and on the passivation film, and a resist pattern having an opening located on the pad on the under bump metal film And a step of forming bumps on the under bump metal film using the resist pattern as a mask.

Further, in the backside grinding method according to the present invention, it is preferable that the protective tape has at least a base film coated with an adhesive material.

Further, in the back surface grinding method according to the present invention, the vacuum suction plate is provided with a plurality of suction holes provided on the suction surface and vacuum piping provided inside the vacuum suction disk. One side may be connected to the suction hole and the other side of the vacuum pipe may be connected to a vacuuming mechanism.

Further, in the back surface grinding method according to the present invention, the rotary grinder has a disk shape and is supported by a rotary shaft, and the rotary shaft may be connected to a mechanism for rotating the rotary shaft. It is possible.

A method of manufacturing a semiconductor device according to the present invention comprises a step of forming bumps on a semiconductor wafer by using a resist pattern as a mask, a step of attaching a protective tape on the bumps and the resist pattern, and vacuuming the protective tape. The step of holding a semiconductor wafer by vacuum suction with a suction disk, and grinding the back surface of the semiconductor wafer by pressing the back surface of the semiconductor wafer held by a vacuum suction disk against the surface of a rotating rotary grinding machine. And a step of removing the protective tape from the back surface of the semiconductor wafer, and a step of removing the resist pattern from the semiconductor wafer.

In the method of manufacturing a semiconductor device according to the present invention, the steps of forming the bumps include the steps of forming a pad on the insulating film, the step of forming a passivation film on the pad, and the passivation film. , A step of forming an opening located on the pad, a step of forming an under bump metal film in the opening and on the passivation film, and on the under bump metal film,
A step of forming a resist pattern having an opening located on the pad, a step of forming a bump on the under bump metal film by using this resist pattern as a mask,
It is preferable that

Further, the method of manufacturing a semiconductor device according to the present invention can further include a step of dicing the semiconductor wafer into semiconductor chips after the step of removing the resist pattern.

The method of manufacturing a semiconductor device according to the present invention can further include a step of mounting a semiconductor chip on a substrate after the dividing step.

The backside grinding method according to the present invention comprises a step of forming dummy bumps on the outer peripheral portion of the surface of a semiconductor wafer, a step of attaching a protective tape to the surface of the semiconductor wafer, and a vacuum suction board for vacuuming the protective tape. A step of adsorbing and holding the semiconductor wafer, and a step of grinding the back surface of the semiconductor wafer by pressing the back surface of the semiconductor wafer held by a vacuum suction disk against the surface of a rotating grinding machine that is rotating, It is characterized by including.

According to the above backside grinding method, since the dummy bumps are formed on the outer peripheral portion of the semiconductor wafer, the height of the entire surface of the protective tape is made uniform when the protective tape for grinding is attached to the surface of the semiconductor wafer. Can be height.
Thereby, when the back surface of the semiconductor wafer with bumps is pressed against the surface of the rotary grinding machine, this pressing force can be uniformly applied to the entire surface of the semiconductor wafer. Further, the bending of the wafer due to the bumps can be reduced, or the area where the bending of the wafer occurs can be outside the effective chip (that is, within the area where the dummy bumps are formed), and stable back surface grinding becomes possible. Therefore, it is possible to reduce variations in the grinding thickness in the chip.

Further, in the back surface grinding method according to the present invention, it is preferable that the dummy bump is formed 4 mm inside from the outermost periphery of the semiconductor wafer in the step of forming the dummy bump.

A method of manufacturing a semiconductor device according to the present invention comprises a step of forming dummy bumps on the outer peripheral portion of the surface of a semiconductor wafer, a step of attaching a protective tape to the surface of the semiconductor wafer, and a vacuum suction board for the protective tape. And a step of holding the semiconductor wafer by vacuum suction by the method, and a step of grinding the back surface of the semiconductor wafer by pressing the back surface of the semiconductor wafer held by the vacuum suction disk against the surface of the rotating rotary grinding machine. And a step of peeling the protective tape from the back surface of the semiconductor wafer, and a step of dividing the semiconductor wafer into semiconductor chips by dicing.

The method of manufacturing a semiconductor device according to the present invention can further include a step of mounting a semiconductor chip on a substrate after the dividing step.

[0028]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. 1 to 4 are views for explaining the method for manufacturing a semiconductor device according to the first embodiment of the present invention. 1A to 1C are cross-sectional views showing a process of forming bumps. FIG. 2 is an enlarged cross-sectional view showing a part of the state in which the protective tape is attached to the semiconductor wafer having the bumps shown in FIG. 1C. Figure 3
It is sectional drawing which shows a mode that the semiconductor wafer to which the protective tape shown in FIG.
FIG. 4 is a cross-sectional view illustrating the next step after backside grinding.

First, as shown in FIG. 1A, a CVD (Chemical Vapor Depositi) is formed on a silicon substrate (not shown).
The interlayer insulating film 11 such as a silicon oxide film is deposited by the on) method. Then, an Al alloy film is deposited on this interlayer insulating film 11 by the sputtering method. Next, a photoresist film (not shown) is applied on the Al alloy film, and the photoresist film is exposed and developed to form a resist pattern on the Al alloy film. After that, the Al alloy film is etched using this resist pattern as a mask, so that the Al alloy pad 1 is formed on the interlayer insulating film 11.
2 and Al alloy wiring (not shown) are formed. The Al alloy pad 12 is electrically connected to a semiconductor element (not shown) via an Al alloy wiring.

Next, a passivation film 13 made of a silicon nitride film is deposited on the Al alloy pad 12 and the interlayer insulating film 11 by the CVD method. Next, a photoresist film is applied on the passivation film 13, and the photoresist film is exposed and developed to form a resist pattern 21 on the passivation film 13.

After that, as shown in FIG. 1B, the passivation film 13 is etched by using the resist pattern 21 as a mask, so that the opening 13a located on the Al alloy pad 12 is formed in the passivation film 13.
Is formed, and the Al alloy pad 1 is formed by the opening 13a.
The surface of 2 is exposed. Next, an under bump metal film 14 made of TiW or the like is formed by a sputtering method on the entire surface including the opening 13a and the passivation film 13.

Next, a photoresist film is applied on the under bump metal film 14, and the photoresist film is exposed and developed. As a result, on the under bump metal film 14, a resist pattern 22 having an opening 22a in a bump formation region located on the Al alloy pad 12 is formed.
Is formed.

Thereafter, as shown in FIG. 1C, the resist pattern 22 is used as a mask on the under bump metal film 14 by a metal plating method, for example, to have a height of 15-2.
A gold bump 19 of about 0 μm is formed.

Next, the protective tape 15 shown in FIG. 2 is prepared. The protective tape 15 has an intermediate film 15b arranged between a base film 15a and an adhesive material 15c. The intermediate film 15b is pressed and deformed. In addition, the base film 15a of the protective tape 15
Is a polyester-based plastic film having a high hardness that hardly deforms even when pressed. The intermediate film 15b is a polyester plastic film, but has a feature that it is easily deformed by pressing. In addition, the adhesive material 15c is the intermediate film 15
It is applied to b in a predetermined thickness.

Then, the protective tape 15 is formed on the gold bumps 19 and the resist pattern 22 shown in FIG. 1C, that is, on the surface of the semiconductor wafer 10 shown in FIG. 2 on which the gold bumps 19 are formed.
To stick. Since the intermediate film 15b of the protective tape 15 is easily deformed by pressing as described above, the adhesive material 15c of the protective tape 15 and the surface of the bumped semiconductor wafer are brought into close contact with each other without a gap. As a result, the surface of the semiconductor wafer 10 on which the gold bumps and the resist pattern 22 are formed as shown in FIG. 2 is protected by the protective tape 15.

Thereafter, the back surface grinding apparatus shown in FIG. 3 is prepared. This backside grinding device is equipped with a vacuum suction board 17,
The vacuum suction plate 17 vacuum-sucks the protective tape 15 attached to the semiconductor wafer 10, thereby fixing and holding the semiconductor wafer when the back surface of the semiconductor wafer is ground. The suction surface of the vacuum suction board 17 is provided with a plurality of suction holes. A vacuum pipe is provided inside the vacuum suction board 17, and one side of the vacuum pipe is connected to the suction hole.
The other side of the vacuum piping is evacuated by a vacuum evacuation mechanism such as a vacuum pump. Further, the back surface grinding apparatus is provided with a disk-shaped rotary grinding machine 18 formed by abrasive grains of about 2000 to 4000 as a rotary grinding mechanism, and the rotary grinding machine 18 is supported by a rotary shaft 18a. . The rotary shaft 18a is connected to, for example, a motor (not shown) as a rotary mechanism, and the rotary shaft 18a is rotated by this motor as shown by an arrow to rotate the rotary grinding machine 18.
Is designed to rotate. In addition, the rotary grinder 18
The operations of the vacuum suction board 17 and the vacuum suction board 17 are controlled by a controller (not shown).

Next, the vacuum suction disk 1 of this back surface grinding apparatus
The suction surface of 7 is brought into contact with the protective tape 15, and the semiconductor wafer with bumps 10 is vacuum-sucked and held on the suction surface of the vacuum suction disk. Then, the back surface of the semiconductor wafer 10 with bumps is pressed against the surface of the rotary grinding machine 18 which is supported by the rotating shaft 18a and is rotating in the direction of the arrow.

Next, after the back surface of the semiconductor wafer 10 is ground for a predetermined time, the vacuum suction disk 17 is moved upward in the back surface grinding device to remove the contact between the surface of the rotary grinding machine 18 and the back surface of the semiconductor wafer 10. Next, the semiconductor wafer 10 is removed from the vacuum suction board 17.

After that, the protective tape 15 is peeled off from the surface of the semiconductor wafer 10. Next, as shown in FIG. 4, the resist pattern 22 is peeled off, and the under bump metal film 14 is etched using the gold bumps 19 as a mask. As a result, the under bump metal film 14 located under the gold bumps 19 is left, and the other under bump metal films are removed.

Next, the semiconductor wafer is diced and divided into semiconductor chips. In the semiconductor chip manufactured in this way, the thin and long flat LCD driver chip, which has been slimmed down, can reduce the difference in the plate thickness of the chip even at the outermost peripheral chip of the wafer.

Next, the semiconductor chip is mounted on a film or a glass substrate by COF (chip on film) or COG.

According to the first embodiment described above, after the gold bumps 19 are formed on the surface of the semiconductor wafer 10 using the resist pattern 22 as a mask, the resist pattern 22 is formed.
Without removing the gold bump 19 and the resist pattern 22.
Protective tape 15 is attached on the top. For this reason, it is possible to reduce the step formed on the surface of the protective tape due to the unevenness due to the gold bump as in the prior art. In particular, the step difference near the outermost periphery of the wafer can be made smaller than in the conventional technique. Therefore, when the back surface of the wafer 10 is ground, the entire front surface of the wafer can be pressed uniformly, thereby improving the grinding accuracy of the back surface of the wafer. As a result, it is possible to suppress variations in the grinding thickness of the back surface of the wafer.

5 to 7 are views for explaining a method of manufacturing a semiconductor device according to the second embodiment of the present invention.
FIG. 5 is a plan view showing a semiconductor device according to the second embodiment of the present invention.

The semiconductor device shown in FIG. 5 is a semiconductor wafer 31.
A plurality of semiconductor chips are formed on it. This semiconductor chip includes a product chip 32 and a dummy chip 33. The product chip 32 is formed in the effective chip area on the surface of the semiconductor wafer, and the dummy chip 33 is formed in an area other than the effective chip area and about 4 mm inside the outermost periphery of the semiconductor wafer. here,
Although it is about 4 mm inside from the outermost periphery of the semiconductor wafer,
The present invention is not limited to this, and can be appropriately changed depending on the semiconductor manufacturing apparatus used during manufacturing.

A plurality of bumps (not shown) are formed on each of the product chip 32 and the dummy chip 33.
The bumps can be formed by using various methods, for example, electroplating.

Semiconductor elements and the like are formed on the product chip 32. This semiconductor element or the like can be formed by using various semiconductor processes, for example, a CVD process, a lithography technique, an exposure technique, an etching technique, or the like.

A plurality of dummy bumps (not shown) are formed on the dummy chip 33, and these dummy bumps are arranged at the same positions as the bumps formed on the product chip 32. By arranging the dummy bumps in this manner, the bumps can be arranged near the outer periphery of the semiconductor wafer (around 4 mm inside from the outermost periphery), which is not arranged in the conventional semiconductor wafer. It is not always necessary to form a semiconductor element or the like on the dummy chip 33.
The dummy bumps only may be formed. However, it is possible to form a semiconductor element or the like on the dummy chip 33 as well as the product chip 32.

Next, a method of grinding the back surface of the bumped substrate (semiconductor wafer) according to the second embodiment will be described with reference to FIGS. 6 and 7.

FIG. 6A shows a protective tape which is attached to the front surface of the semiconductor wafer when the back surface of the semiconductor wafer shown in FIG. 5 is ground. FIG. 6B is a sectional view taken along line 5b-5b shown in FIG. 6C is a cross-sectional view showing a state in which the protective tape shown in FIG. 6A is attached to the surface of the semiconductor wafer shown in FIG. 6B. FIG. 7 shows FIG.
It is sectional drawing which expanded the area | region 3 shown to (c).

First, the protective tape 15 shown in FIG. 6 (a) is prepared. The protective tape 15 is the same as that used in the first embodiment.

Next, the protective tape 15 shown in FIG. 6A is adhered to the surface of the semiconductor wafer shown in FIG. 6B on which the bumps 19 are formed. Intermediate film 15b of protective tape 15
Since it is easily deformed by pressing as described above, the adhesive material 15c of the protective tape 15 and the surface of the bumped semiconductor wafer are brought into close contact with each other without a gap. As a result, FIG.
The surface of the semiconductor wafer 31 with bumps is protected by the protective tape 15 as shown in FIG. At this time, as shown in FIG. 7, a step portion L is formed on the outer periphery of the protective tape 15,
This step portion L is about 4 mm. That is, by arranging the dummy bumps, the vicinity of the outer periphery of the semiconductor wafer which is not arranged in the conventional semiconductor wafer (4 from the outermost periphery) is arranged.
Since the bumps are also placed around the inside (about mm),
The stepped portion of the protective tape 15 can be shortened. This makes it possible to make the surface of the protective tape 15 attached to the surface of the semiconductor wafer with bumps, in particular the outer peripheral portion, flatter than in the conventional case, and to reduce steps.

Thereafter, the back surface grinding apparatus shown in FIG. 3 is prepared. Next, the suction surface of the vacuum suction disk 17 of this backside grinding device is brought into contact with the protective tape 15 to hold the bumped semiconductor wafer 31 by vacuum suction on the suction surface of the vacuum suction disk. Then, the back surface of the bumped semiconductor wafer 31 is pressed against the surface of the rotary grinding machine 18 which is supported by the rotary shaft 18a and is rotating in the direction of the arrow.

Next, after the back surface of the semiconductor wafer 31 is ground for a predetermined time, the vacuum suction disk 17 is moved upward in the back surface grinding device to remove the contact between the surface of the rotary grinding machine 18 and the back surface of the semiconductor wafer 31. Next, the semiconductor wafer 31 is removed from the vacuum suction board 17.

After that, the protective tape 15 is peeled off from the surface of the semiconductor wafer 31, and the semiconductor wafer 31 is diced into semiconductor chips. In the semiconductor chip manufactured in this way, the slim, flat-panel LCD
It is possible to reduce the difference in the inner plate thickness of the chip even for the driver chip, which is the outermost peripheral chip of the wafer.

Next, the semiconductor chip is mounted on the film or the glass substrate by COF or COG.

According to the second embodiment, the dummy chip and the dummy bump are formed near the outer periphery of the semiconductor wafer, and the bump is formed up to the outermost periphery of the semiconductor wafer of about 4 mm. Therefore, when the protective tape for grinding is attached to the surface of the semiconductor wafer, the height of the entire surface of the protective tape can be made uniform. Thereby, when the back surface of the semiconductor wafer 31 with bumps is pressed against the surface of the rotary grinding machine 18, this pressing force can be uniformly applied to the entire surface of the semiconductor wafer 31. In addition, the bending of the wafer due to the bumps can be reduced, or the area where the bending of the wafer occurs can be outside the effective chip (that is, inside the dummy chip), and stable back surface grinding becomes possible. Therefore, the size of the product chip and the shot map at the time of exposure are not affected, and it is possible to reduce the variation in the grinding thickness in the chip.

The present invention is not limited to the above-mentioned embodiment, and can be implemented with various modifications. For example,
In the above embodiment, the base film 15a and the adhesive material 1
The protective tape 15 in which the intermediate film 15b is disposed between the protective tape 15 and 5c is used, but the invention is not limited to this.
It is also possible to use a protective tape having another structure as long as it is a protective tape having at least a base film coated with an adhesive material.

[0058]

As described above, according to the present invention, after a bump is formed on a semiconductor wafer using a resist pattern as a mask, the resist pattern is not removed and a protective tape is applied on the bump and the resist pattern. Attached. Therefore, it is possible to provide a backside grinding method and a semiconductor device manufacturing method that reduce the variation in the thickness of the inside of the chip after the backside grinding of the semiconductor wafer.

[Brief description of drawings]

FIG. 1 is a diagram for explaining a method of manufacturing a semiconductor device according to a first embodiment of the present invention,
FIG. 7C is a sectional view showing a step of forming bumps.

FIG. 2 illustrates a method for manufacturing a semiconductor device according to a first embodiment of the present invention, in which a protective tape is attached to a semiconductor wafer having bumps shown in FIG. 1C. It is sectional drawing which expands and shows a part of.

FIG. 3 is a view for explaining the method of manufacturing a semiconductor device according to the first embodiment of the present invention, in which a semiconductor wafer having a protective tape attached thereto shown in FIG. 2 is ground by a back surface grinding device. FIG.

FIG. 4 is a cross-sectional view for explaining the method for manufacturing the semiconductor device according to the first embodiment of the present invention, which illustrates the next step after backside grinding.

FIG. 5 is a plan view showing the semiconductor device for explaining the method for manufacturing the semiconductor device according to the second embodiment of the present invention.

FIG. 6 illustrates a method for manufacturing a semiconductor device according to a second embodiment of the present invention, in which (a) shows a semiconductor wafer front surface when the back surface of the semiconductor wafer shown in FIG. 5 is ground. It is a protective tape to be attached, and (b) is shown in FIG.
FIG. 5C is a cross-sectional view taken along line 5b-5b shown in FIG.
It is sectional drawing which shows the state which stuck the protective tape shown to (a) on the surface of the semiconductor wafer shown to (b).

FIG. 7 illustrates a method for manufacturing a semiconductor device according to a second embodiment of the present invention, and FIG.
It is sectional drawing which expanded the area | region 3 shown in FIG.

FIG. 8 is a plan view showing a conventional semiconductor device.

FIG. 9 is a partial cross-sectional view showing a state in which a protective tape for protecting the front surface of the wafer is attached to the wafer when the back surface of the bumped wafer is ground.

[Explanation of symbols]

10, 31, 111 ... Semiconductor wafer 11 ... Interlayer insulating film 12 ... Al alloy pad 13 ... passivation film 13a ... opening 14 ... Under bump metal film 15,115 ... Protective tape 15a ... Base film 15b ... Intermediate film 15c ... Adhesive material 17 ... Vacuum suction board 18 ... Rotary grinding machine 18a ... rotary shaft 19,116 ... Gold bump 21, 22 ... Resist pattern 22a ... opening 32, 112 ... Product chips 33 ... Dummy chip 110 ... Invalid chip area

Claims (13)

[Claims] 1. A step of forming bumps on a semiconductor wafer by using a resist pattern as a mask, a step of attaching a protective tape on the bumps and the resist pattern, and vacuum suction of the protective tape by a vacuum suction plate to form a semiconductor wafer. And a step of grinding the back surface of the semiconductor wafer by pressing the back surface of the semiconductor wafer held by the vacuum suction disk against the surface of the rotating rotary grinding machine. A characteristic backside grinding method. 2. The step of forming the bump includes the step of forming a pad on the insulating film, the step of forming a passivation film on the pad, and the step of forming an opening located on the pad in the passivation film. And a step of forming an under bump metal film in the opening and on the passivation film, a step of forming a resist pattern having an opening located on the pad on the under bump metal film, and the resist pattern Forming a bump on the under-bump metal film by using the mask as a mask.
The backside grinding method described in. 3. The backside grinding method according to claim 1, wherein the protective tape has at least a base film coated with an adhesive material. 4. The vacuum suction plate comprises a plurality of suction holes provided on its suction surface and a vacuum pipe provided inside, and one side of the vacuum pipe is connected to the suction hole. The backside grinding method according to claim 1, wherein the other side of the vacuum pipe is connected to a vacuuming mechanism. 5. The rotary grinding machine has a disk shape,
A rotary shaft is supported by the rotary shaft, and the rotary shaft is connected to a mechanism for rotating the rotary shaft.
The backside grinding method according to claim 1. 6. A step of forming bumps on a semiconductor wafer by using a resist pattern as a mask, a step of attaching a protective tape on the bumps and the resist pattern, and vacuum suction of the protective tape by a vacuum suction plate to form a semiconductor wafer. And a step of grinding the back surface of the semiconductor wafer by pressing the back surface of the semiconductor wafer held by the vacuum suction disk against the surface of the rotating rotary grinding machine, and a back surface of the semiconductor wafer. And a step of removing the resist pattern from the semiconductor wafer, a method of manufacturing a semiconductor device, comprising: 7. The step of forming the bump includes the step of forming a pad on the insulating film, the step of forming a passivation film on the pad, and the step of forming an opening located on the pad in the passivation film. And a step of forming an under bump metal film in the opening and on the passivation film, a step of forming a resist pattern having an opening located on the pad on the under bump metal film, and the resist pattern 7. A step of forming a bump on the under bump metal film by using the mask as a mask.
A method of manufacturing a semiconductor device according to item 1. 8. The method of manufacturing a semiconductor device according to claim 6, further comprising a step of dicing the semiconductor wafer into semiconductor chips after the step of removing the resist pattern. 9. The method of manufacturing a semiconductor device according to claim 8, further comprising a step of mounting a semiconductor chip on a substrate after the dividing step. 10. A step of forming a dummy bump on the outer peripheral portion of the surface of a semiconductor wafer, a step of attaching a protective tape to the surface of this semiconductor wafer, and a vacuum suction of this protective tape by a vacuum suction plate to hold the semiconductor wafer. And a step of grinding the back surface of the semiconductor wafer by pressing the back surface of the semiconductor wafer held by the vacuum suction disk against the surface of a rotating grinding machine that is rotating. Back grinding method. 11. The backside grinding method according to claim 10, wherein in the step of forming the dummy bumps, the dummy bumps are formed 4 mm inside from the outermost periphery of the semiconductor wafer. 12. A step of forming a dummy bump on an outer peripheral portion of a surface of a semiconductor wafer, a step of attaching a protective tape to the surface of the semiconductor wafer, and a vacuum suction of the protective tape by a vacuum suction plate to hold the semiconductor wafer. And a step of grinding the back surface of the semiconductor wafer by pressing the back surface of the semiconductor wafer held by the vacuum suction disk against the surface of the rotating grinding machine during rotation, and a step of protecting the back surface of the semiconductor wafer from the back surface. A method of manufacturing a semiconductor device, comprising: a step of peeling a tape; and a step of dicing the semiconductor wafer into semiconductor chips. 13. The method of manufacturing a semiconductor device according to claim 12, further comprising a step of mounting a semiconductor chip on a substrate after the dividing step.