JPH11193497A - Plating device for wafer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a plating device for a wafer capable of uniformizing the electric field in a wide range on the wafer face and capable of forming plating coating uniform in coating thickness. SOLUTION: In a wafer plating device in which a wafer 1 mounted on a plating jig 4 and an anode electrode 2 are oppositely arranged in a plating tank 5 stored with a plating liq. Q, and the electric current is caused to flow to the space between the anode electrode 2 and the wafer 1 to form plating coating on the face of the wafer 1, on the space between the wafer 1 and the anode electrode 2, one dielectric planar sheet or a plurality of dielectric planar sheets 3 composed of dielectric material in which holes of the shape concentrically circular with those of the wafer 1 are formed are arranged.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wafer plating apparatus used for plating a surface of a wafer.

[0002]

2. Description of the Related Art Conventionally, when plating is performed on a wafer surface, a wafer mounted on a plating jig and an anode electrode are arranged in a plating solution tank containing a plating solution, and current is applied to the wafer from the anode electrode. I do it. In this case, the plating film formed on the wafer surface is affected by the electric field between the wafer and the anode electrode. If the potential distribution near the wafer surface is not uniform, the thickness of the plating film formed on the wafer surface is also uneven. become. In particular, the electric field is disturbed at the edge of the wafer and the edge of the anode electrode, and there is a problem that a plating film having a uniform thickness cannot be formed on the wafer surface. Therefore, conventionally, the electric field has been adjusted by adjusting the size of the anode electrode or inserting a shielding plate made of a dielectric material between the anode electrode and the wafer.

[0003]

However, in the method of adjusting the size of the anode electrode or inserting a shielding plate made of a dielectric material between the anode electrode and the wafer to adjust the electric field,
There is a problem that the range of the electric field that can be adjusted is narrow, and the electric field cannot be made uniform over a wide range of the wafer surface.

The present invention has been made in view of the above points, and provides a wafer plating apparatus which can make an electric field uniform over a wide range on a wafer surface and can form a plating film having a uniform thickness on the wafer surface. The purpose is to do.

[0005]

According to the first aspect of the present invention, a wafer and an anode are opposed to each other in a plating solution tank containing a plating solution. In a wafer plating apparatus for forming a plating film on a wafer surface by passing a current, one or more dielectric flat plates made of a dielectric material having a hole formed concentrically with the wafer are arranged between the wafer and an anode electrode. It is characterized by the following.

[0006] The invention described in claim 2 is the invention according to claim 1.
Wherein the diameter of the hole formed in the dielectric flat plate is smaller than the outer diameter of the wafer.

According to a third aspect of the present invention, a wafer and an anode electrode are opposed to each other in a plating solution tank containing a plating solution, and a current is applied between the anode electrode and the wafer to form a plating film on the wafer surface. Is characterized in that a dielectric cylinder formed of a porous body made of a dielectric material or a mesh-like body made of a dielectric material is arranged between a wafer and an anode electrode.

[0008] The invention described in claim 4 is the invention according to claim 3.
Wherein the inner diameter of the dielectric cylinder is smaller than the outer diameter of the wafer.

The invention described in claim 5 is the third invention.
Alternatively, in the apparatus for plating a wafer described in 4, the dielectric cylinder is configured to be rotated by a rotating means.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a view showing a configuration of a plating apparatus according to the first aspect of the present invention. As shown in the drawing, the present plating apparatus has a plating tank 5, and a plating solution Q is contained in the plating tank 5. The wafer 1 mounted on the plating jig 4 and the anode electrode 2 are arranged in the plating solution Q of the plating tank 5 so as to face each other.
Between them, three dielectric flat plates 3-1, 3-2, 3-3 made of a dielectric material having holes formed concentrically with the wafer 1 are arranged. A plating power source 6 is connected between the anode electrode 2 and the wafer 1, and a current is applied to the wafer 1 from the anode electrode 2 to form a plating film on the surface of the wafer 1.

In FIG. 1, reference numeral 7 denotes an outer tank arranged outside the plating tank 5, and the plating solution overflowing the upper end of the plating tank 5 by the pump 8 and flowing into the outer tank 7 is supplied to the constant temperature unit 9 and the constant temperature unit 9. Through the filter 10, the plating tank 5
The plating solution is circulated by injecting from the bottom of the plating solution. The constant temperature unit 9 is provided to maintain the temperature of the plating solution at a predetermined temperature (for example, normal temperature to 65 ° C.).

FIG. 2 is an external perspective view showing the shape of the dielectric flat plate 3. The dielectric plate 3 is formed of a dielectric material such as vinyl chloride or heat-resistant vinyl chloride having a hole 3a concentric with the wafer 1 formed in the center. The diameter of the hole 3a is smaller than the outer diameter of the wafer 1 by a predetermined dimension. A predetermined distance (see FIG. 3) between the wafer 1 and the anode electrode 2 so that the hole 3a formed in the center of the dielectric flat plate 3-1, 3-2, 3-3 having the above shape is concentric with the wafer 1. At equal intervals).

FIGS. 3A and 3B show the results of analysis of the electric field of the wafer 1 and the anode electrode 2 of the plating apparatus. FIG. 3A shows the case where there is no dielectric flat plate, and FIG. FIG. 3C shows five dielectric flat plates 3 (3-1, 3-1) when one is arranged.
3-2, 3-3, 3-4, 3-5). As is clear from the figure, FIG.
Compared with the case of (a), in the case of FIG. 3B in which one dielectric flat plate 3 is arranged, the electric field is uniform over a wide area of the surface of the wafer 1, and further, five dielectric flat plates 3 are arranged. Fig. 3
(C) shows that the electric field becomes more uniform over a wider area of the surface of the wafer 1.

FIG. 4 is a diagram showing a film thickness distribution of a plating film when the surface of the wafer 1 is plated by the plating apparatus. FIG. 4A shows a case where there is no dielectric flat plate, and FIG. FIG. 4C shows a case where one dielectric flat plate 3 is arranged.
Are arranged (5-1, 3-2, 3-3, 3-4, 3-5). As shown in the figure, the plating film thickness shows the results of examination of the wafer 1 in the Y direction (marked by ○) and the X direction (marked by Δ). As is clear from the figure, the plating film becomes more uniform in the case of FIG. 4B where one dielectric flat plate 3 is arranged, as compared with the case of FIG. It can be seen that the plating film is more uniform in FIG. 4C in which five body flat plates 3 are arranged.

By arranging a plurality of dielectric flat plates 3 between the wafer 1 and the anode electrode 2 as described above, the electric field near the surface of the wafer 1 can be reduced without the electric field sneaking from outside the wafer 1. And the thickness of the plating film deposited on the surface of the wafer 1 becomes uniform.
Further, in the plating apparatus shown in FIG.
1. There is a gap between the dielectric plate 3-1 and the dielectric plate 3-2, between the dielectric plate 3-2 and the dielectric plate 3-3, and between the dielectric plate 3-3 and the anode electrode 2. Through which the plating solution Q can enter and exit, and the stirring of the plating solution Q can be performed effectively, so that the concentration and temperature of the plating solution Q can be kept uniform and formed on the surface of the wafer 1. The growth rate of the plating film can be made constant.

FIG. 5 is a view showing a configuration of a plating apparatus according to the third aspect of the present invention. As shown in the drawing, the present plating apparatus has a plating tank 5, and a plating solution Q is contained in the plating tank 5. A wafer 1 mounted on a plating jig 4 and an anode electrode 2 are arranged opposite to each other in a plating solution Q in a plating tank 5, and a mesh-like body made of a dielectric material is interposed between the wafer 1 and the anode electrode 2. Dielectric cylinder 11 formed of
Has been arranged.

FIG. 6 is an external perspective view showing the appearance of the dielectric cylinder 11. The dielectric cylinder 11 is made of a dielectric mesh such as vinyl chloride or heat-resistant vinyl chloride. The inner diameter D of the wafer 11 is smaller than the outer diameter of the wafer 1 by a predetermined dimension. The dielectric cylinder 11 is not limited to a mesh-shaped body, but may be a porous body made of a dielectric.

Further, the dielectric cylinder 11 is not limited to being disposed in a stationary state between the wafer 1 and the anode electrode 2, and as shown in FIG. Motor 14 via a rotation transmission mechanism comprising
It may be configured to rotate with. By rotating the dielectric cylinder 11 between the wafer 1 and the anode electrode 2 in this manner, the dielectric cylinder 11 stirs the plating solution,
There is no need to separately provide a plating solution stirring device.

In the plating apparatus having the above structure, the pump 8
The plating solution flowing into the outer bath 7 after overflowing the upper end of the plating bath 5 through the constant temperature unit 9 and the filter 10 is injected from the bottom of the plating bath 5 to circulate the plating solution, and the anode electrode 2 A plating power supply 6 is connected between the anode electrode 2 and the wafer 1.
The point that a plating film is formed on the surface of the wafer 1 by applying a current to the wafer 1 is the same as the plating apparatus having the configuration shown in FIG.

FIGS. 8A and 8B show the results of analysis of the electric field of the wafer 1 and the anode electrode 2 of the plating apparatus shown in FIG. 5. FIG. 8A shows the case where the dielectric cylinder 11 is not provided, and FIG. This shows a case where a body cylinder is arranged. As is clear from the figure, the electric field in the case of FIG. 8B in which the dielectric cylinder 11 is arranged is larger than that in FIG. It turns out that it becomes uniform.

As described above, by arranging the dielectric cylinder 11 formed of a porous body made of a dielectric material or a mesh-like body made of a dielectric material between the wafer 1 and the anode electrode 2, the electric field is increased. The potential of the plating film deposited on the surface of the wafer 1 becomes uniform over the entire surface of the wafer 1 as a result. Further, since the dielectric cylinder 11 is formed of a porous body or a mesh-like body, the plating solution Q enters and exits through the porous body or the mesh, and the plating solution Q
Is stirred and the concentration and temperature of the plating solution Q become uniform, so that the growth rate of the formed plating film on the surface of the wafer 1 becomes constant.

[0022]

As described above, according to the first and second aspects of the present invention, a dielectric flat plate made of a dielectric material having a hole formed concentrically with the wafer is formed between the wafer and the anode electrode.
Since one or more sheets are arranged, the following excellent effects can be obtained.

The electric field does not wrap around the outside of the wafer, and the potential near the surface of the wafer becomes uniform over the entire surface of the wafer. As a result, the thickness of the plating film deposited on the surface of the wafer 1 becomes uniform.

Since there are gaps between the wafer and the dielectric plate, between the dielectric plate and the dielectric plate, and between the dielectric plate and the anode electrode,
Since the plating solution can enter and exit through the gap, and the plating solution is stirred, the concentration and temperature of the plating solution can be kept uniform, and the growth rate of the plating film formed on the wafer surface is constant. Become.

According to the present invention, a dielectric cylinder formed of a porous body made of a dielectric material or a mesh body made of a dielectric material is arranged between the wafer and the anode electrode. Therefore, the following excellent effects can be obtained.

The electric field rarely wraps around the outer periphery of the wafer, and the electric potential near the surface of the wafer becomes uniform over the entire surface of the wafer. As a result, the thickness of the plating film deposited on the surface of the wafer 1 becomes uniform.

Since the dielectric cylinder is formed of a porous body or a mesh-like body, the plating solution enters and exits through the porous body or the mesh and the plating solution is stirred, so that the concentration and temperature of the plating solution become uniform. The concentration and temperature of the plating solution can be kept uniform, and the growth rate of the plating film formed on the surface of the wafer becomes constant.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a plating apparatus according to the first aspect of the present invention.

FIG. 2 is an external perspective view showing the shape of a dielectric flat plate.

3 (a) to 3 (c) are diagrams showing the results of analysis of the electric field of the wafer and the anode electrode of the plating apparatus of FIG. 1;

4 (a) to 4 (c) are diagrams showing a film thickness distribution of a plating film when plating is performed on a wafer surface by the plating apparatus of FIG.

FIG. 5 is a diagram showing a configuration of a plating apparatus according to the third aspect of the present invention.

FIG. 6 is an external perspective view showing the shape of a dielectric cylinder.

FIG. 7 is an external perspective view showing the shape of a dielectric cylinder rotatably configured.

8 (a) and 8 (b) are diagrams showing the results of analysis of the electric field of the wafer and the anode electrode of the plating apparatus of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Wafer 2 Anode electrode 3 Dielectric flat plate 4 Plating jig 5 Plating tank 6 Plating power supply 7 Outer tank 8 Pump 9 Constant temperature unit 10 Filter 11 Dielectric cylinder 12 Gear 13 Gear 14 Motor

Claims (5)

[Claims] A wafer plating apparatus in which a wafer and an anode electrode are arranged to face each other in a plating solution tank containing a plating solution, and a current is applied between the anode electrode and the wafer to form a plating film on the wafer surface. A wafer plating apparatus, wherein one or more dielectric flat plates made of a dielectric material having concentric holes formed between the wafer and the anode electrode are arranged. 2. The wafer plating apparatus according to claim 1, wherein a diameter of the hole formed in the dielectric flat plate is smaller than an outer diameter of the wafer. 3. A wafer plating apparatus in which a wafer and an anode electrode are opposed to each other in a plating solution tank containing a plating solution, and a current is applied between the anode electrode and the wafer to form a plating film on the wafer surface. A wafer plating apparatus, wherein a dielectric cylinder formed of a porous body made of a dielectric material or a mesh body made of a dielectric material is arranged between the wafer and the anode electrode. 4. The apparatus according to claim 3, wherein an inner diameter of the dielectric cylinder is smaller than an outer diameter of the wafer. 5. The wafer plating apparatus according to claim 3, wherein the dielectric cylinder is configured to be rotated by rotating means.