JP2911882B1 - Cup type plating equipment - Google Patents

Abstract

An object of the present invention is to provide a technique capable of performing good plating even when a wafer in which a seed metal is previously applied to a surface to be plated is sequentially replaced by a cup-type plating apparatus and plating is performed. . SOLUTION: A seal support 3 with a cathode electrode is arranged along an opening 2 of a plating tank 1 and a top ring 4 is attached to expose a fixed width at an inner peripheral edge of the seal packing 3 to form a wafer support 5. The plating solution attached to the wafer supporting portion 5 can be removed by suction in a cup-type plating apparatus in which the peripheral portion of the wafer 6 is placed on the substrate and plating is performed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an apparatus for plating a semiconductor wafer, and more particularly to a cup-type plating apparatus.

[0002]

2. Description of the Related Art Conventionally, a cup-type plating apparatus is known as one of apparatuses for plating a semiconductor wafer. In this cup type plating apparatus, a seal packing combined with a cathode electrode is arranged along an opening of a plating tank, a top ring is attached from above, and a constant width is exposed at an inner peripheral edge of the seal packing to form a wafer support. It is formed. Then, the periphery of the wafer is placed on the wafer support portion, and the plating solution is lifted and supplied from below the plating tank, and plating is performed while the plating solution is in contact with the plating target surface of the wafer. I have. This cup-type plating apparatus can continuously perform the same plating process by sequentially changing the wafers placed on the wafer support unit, and is suitable when automating the plating process or when producing small lots. Is widely used as

[0003]

However, in this cup-type plating apparatus, when the wafers are sequentially replaced and the plating is continuously performed, the plating solution adheres to the wafer support when the plated wafer is removed. There are many. Therefore, when a new wafer is placed next, the peripheral portion of the new wafer comes into contact with the plating solution attached to the wafer support.

[0004] This phenomenon is one of the causes of nonuniform plating properties when plating is performed with a cup-type plating apparatus. This is a particular problem in the case of plating a wafer with a seed metal, which has recently started to be widely used, that is, a wafer in which a plating target surface of the wafer is previously coated with a metal such as Cu. When the plating solution is attached to the wafer support, the seed metal is melted by the plating solution at the peripheral portion of the wafer from the time the new seeded metal wafer is placed to the time the plating process is started. It will be. When the seed metal is melted, the plating current supplied from the cathode electrode of the wafer support portion to the surface to be plated of the wafer via the seed metal becomes non-uniform, and a state occurs in which a good plating process cannot be performed.

Accordingly, an object of the present invention is to provide a technique that enables good plating to be performed even when the above-described wafer with a seed metal is sequentially plated using a cup-type plating apparatus.

[0006]

According to the present invention, a seal packing with a cathode electrode is disposed along an opening of a plating tank and a top ring is attached to the seal packing so that the inner circumference of the seal packing is fixed. In a cup-type plating apparatus in which a peripheral portion of a wafer is placed on a wafer supporting portion formed by exposing the width to perform plating, a plating solution attached to the wafer supporting portion can be removed by suction. To remove the plating solution adhering to the wafer supporting portion by suction in the present invention is to provide the cup-type plating apparatus itself with its function, and externally by a suction means or the like provided separately from the plating apparatus. It does not include removing the plating solution attached to the wafer support. With such a cup-type plating apparatus of the present invention, even when performing continuous plating while exchanging wafers, the plating solution attached to the wafer support is removed when exchanging for a new wafer. Even if the wafer has a seed metal, the seed metal at the peripheral portion of the wafer is not dissolved, and the plating current can be supplied uniformly. In addition, even when a highly corrosive plating solution is used, the time required for the plating solution to adhere to the wafer support is shortened, so that early deterioration of the plating apparatus due to corrosion of the wafer support can be prevented. .

In order to remove the plating solution adhering to the wafer supporting portion by suction as described above, a suction hole is provided in the inner periphery of the top ring in the present invention. In the cup-type plating apparatus, since the wafer support is formed inside the inner circumference of the top ring, the plating solution attached to the wafer support can be suctioned and removed by providing the suction hole in the inner circumference of the top ring. . It is preferable to provide a plurality of suction holes provided in the top ring over the entire inner periphery of the top ring so that the plating solution adhered over the entire periphery of the wafer support portion can be suctioned and removed uniformly. Or,
Slit-shaped suction holes may be provided on the entire inner periphery of the top ring. In this case, the suction hole provided on the inner periphery of the top ring may be connected to a suction unit connected to the top ring so that the plating solution can be removed by suction. As described above, since it is relatively easy to remodel the top ring by providing the suction hole, there is an advantage that the cup-type plating apparatus of the present invention can be easily applied to the cup-type plating apparatus conventionally used.

In order to remove the plating solution adhering to the wafer support by suction, a suction hole is formed in the wafer support, and a suction path is provided in the opening of the plating tank following the suction hole. Can also be done. In this case, perforating a suction hole in the wafer support means to perforate a suction hole in a portion of the inner peripheral edge of the seal packing arranged along the opening of the plating tank, where the predetermined width is exposed. It is preferable to provide a plurality of suction holes so as to uniformly remove the plating solution attached on the entire periphery of the wafer supporting portion. Then, a suction path is provided at a position corresponding to the suction hole formed in the seal packing at the opening of the plating tank, and a suction means is connected to an end of the suction path. In this way, the plating solution adhering to the wafer support can be removed by suction, and the mounted wafer itself can be suctioned, so that the wafer can be securely fixed to the wafer support. is there.

Further, the cup-type plating apparatus of the present invention more preferably includes a cleaning liquid supply means for supplying a cleaning liquid to the wafer support. The attached plating solution is likely to crystallize due to a decrease in the solution temperature, etc. However, if the plating solution is suctioned and removed while supplying cleaning water, for example, pure water, to the wafer support portion, the crystallization of the plating solution is prevented. Can,
This makes it possible to prevent the drawing of the suction hole and to always maintain a clean wafer supporting portion.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below. FIG. 1 is a schematic sectional view of a cup-type plating apparatus according to the present embodiment. As shown in FIG. 1, the cup-type plating apparatus according to the present embodiment has a seal packing 3 with a cathode electrode disposed along an upper opening 2 of a plating tank 1, and a top ring 4 is attached from above the seal packing 3. The wafer support portion 5 is formed so as to expose a predetermined width to the inner peripheral edge of the wafer support portion 5. Then, the periphery of the wafer 6 is placed on the wafer support portion 5, and the plating solution is supplied from the plating solution supply portion 7 provided below the plating tank 1 while being raised, and the plating target surface of the placed wafer 6 is placed. The plating is performed while the plating solution is in contact with the plating solution 8.

In the cup-type plating apparatus of the present embodiment, a slit-shaped suction hole 9 is provided on the inner periphery of the top ring 4. FIG. 2 is a schematic plan view of the top ring for the cup-type plating apparatus according to the present embodiment. As can be seen from the figure, the slit-shaped suction holes 9 are provided over the entire periphery of the wafer support 5. The plating solution is provided on the entire circumference so that the adhered plating solution can be removed by suction. A suction unit (not shown) is connected to the discharge unit 10.

FIG. 3 shows an enlarged cross section of the wafer support 5 shown in FIG. The seal packing 3 is formed of a silicone resin, and has a positioning notch 11 and a seal dip 12 with an R at the tip. Then, the seal packing 3 is arranged along the opening 2 of the plating tank 1 by the positioning notch 11. The cathode electrode 13 is attached to the upper surface of the seal packing 3, and when the inner peripheral edge of the seal packing 3 has a constant width exposed, the cathode electrode 13 also exposes a constant width to contact the wafer to be mounted. I have to do it. The plating solution adhering to the wafer supporting portion 5 thus formed is sucked and removed from a slit-shaped suction hole 9 provided on the inner periphery of the top ring 4 by operating a suction device (not shown).

FIG. 4 shows an enlarged cross section of a wafer supporting portion 5 in another embodiment in which a cleaning liquid can be supplied to the wafer supporting portion 5. In this case, the top ring 4 is provided with a slit-shaped suction hole 9 and a cleaning liquid supply hole 14 for supplying a cleaning liquid. The plating solution adhering to the wafer support 5 is removed by suction through the suction holes 9, and at this time, a small amount of pure water is supplied from the cleaning solution supply hole 14 to clean the wafer support 5. The supplied pure water is suction-removed together with the plating solution through the suction holes 9. By supplying such a cleaning liquid, it is possible to prevent the drawing of the suction hole 9 due to crystallization of the plating liquid, and to keep the wafer support 5 in a clean state.

FIG. 5 shows that a suction hole 15 is formed in the wafer support 5.
In the embodiment in which is provided, the cross section of the wafer support portion 5 is enlarged. When the suction hole 15 is provided in the wafer support portion 5, a hole having an appropriate diameter is provided in a portion of the inner peripheral edge of the seal packing 3 where a certain width is exposed, and the opening 2 of the plating tank 1 is provided to follow the hole. A suction path 16 is provided. A plurality of suction holes 15 are provided over the entire circumference of the wafer support portion 5, and a suction passage 16 provided in the opening 2 penetrates to the outer periphery of the plating tank, and a suction device (not shown) is provided on the outer periphery of the plating tank. Is connected to Thereby, the plating solution adhering to the wafer support 5 can be removed by suction, and when a wafer is placed on the wafer support 5, the wafer 6 is suctioned by the suction holes 15 to thereby remove the wafer support. It is also possible to fix to 5.

Even when the suction hole 15 is provided in the wafer support 5 as described above, the cleaning solution supply hole 14 is provided in the top ring 4 so that the plating solution is removed by suction while supplying pure water to the wafer support 5. By doing so, it is possible to prevent the drawing of the suction hole 15 due to the crystallization of the plating solution, and to keep the wafer support 5 in a clean state.

[0016]

As described above, according to the present invention, good plating can be performed even when a wafer with a seed metal is sequentially plated using a cup-type plating apparatus.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view of a cup-type plating apparatus according to one embodiment.

FIG. 2 is a schematic plan view of a top ring for a cup-type plating apparatus according to an embodiment.

FIG. 3 is an enlarged view of a cross section of the wafer supporting unit shown in FIG. 1;

FIG. 4 is an enlarged cross-sectional view of a wafer support in another embodiment that can supply a cleaning liquid.

FIG. 5 is an enlarged cross-sectional view of the wafer support in the embodiment in which suction holes are provided in the wafer support;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Plating tank 2 Opening 3 Seal packing 4 Top ring 5 Wafer support part 6 Wafer 7 Plating solution supply part 8 Plating object surface 9 Suction hole 10 Discharge part 11 Alignment notch 12 Seal dip 13 Cathode electrode 14 Cleaning solution supply hole 15 Suction Hole 16 suction path

Claims (4)

(57) [Claims] 1. A wafer supporting portion formed by arranging a seal packing with a cathode electrode along an opening of a plating tank and attaching a top ring to expose a fixed width at an inner peripheral edge of the seal packing. A cup-type plating apparatus in which a plating solution is mounted on a wafer and a plating solution attached to the wafer support is removed by suction. 2. The cup-type plating apparatus according to claim 1, wherein a suction hole capable of sucking and removing the plating solution is provided on an inner periphery of the top ring. 3. The method according to claim 1, wherein a suction hole capable of sucking and removing the plating solution is formed in the wafer support portion, and a suction passage is provided in the opening of the plating tank so as to follow the suction hole. The cup-type plating apparatus as described in the above. 4. The cup-type plating apparatus according to claim 1, further comprising a cleaning liquid supply means for supplying a cleaning liquid to the wafer support.