JP2648945B2 - Method for manufacturing semiconductor device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Summary of the Invention] The present invention relates to a method of manufacturing a semiconductor device, and more particularly to an improvement of a plating process in a wafer process in an integrated circuit (IC) manufacturing process. It is an object of the present invention to provide a method of manufacturing a semiconductor device capable of performing good plating without plating while maintaining plating, supplying a plating solution from an upper portion of a wafer arranged upward, and removing bubbles and bubbles contained in the plating solution. The method includes a method of manufacturing a semiconductor device, which comprises removing fine particles from a defoaming hole above a wafer and performing plating.

[Industrial applications]

The present invention relates to a method for manufacturing a semiconductor device, particularly to an integrated circuit (I
C) It relates to improvement of a plating process in a wafer process in a manufacturing process.

With the recent increase in the density of ICs, there has been a demand for a higher density of mounting electrodes in one chip. For this reason, it is necessary to form small-sized gold bumps, which are connection electrodes formed on a semiconductor chip, with good yield.

[Conventional technology]

In recent years, the number of LSI electrodes has tended to increase, and in the conventional gold bump formation technology, bumps are formed by gold plating. At this time, the plating solution is supplied from below, and the wafer is turned down over it It was placed and plated.

The method of forming such a gold bump will be briefly described with reference to FIG. 3. As shown in FIG. 3A, a conductor 32 is provided on a silicon substrate 31, and a bump connected to the conductor 32 is formed. As shown in FIG. 3B, a resist 33 is applied on the silicon substrate 31, patterned as shown, and then plated with gold to form a gold bump 35. Finally, as shown in FIG. The resist is removed as shown, leaving the gold bump 35 connected to the conductor 32.

The apparatus shown in FIG. 4 (a) is used to make the gold plating. In the figure, 41 is a main tank, 42 is a sub tank, 43 is a plating part, and a plating solution 44 shown with diagonal lines.
Is supplied from the sub-tank 42 to the plating unit 43 via the magnet pump 45, while the plating solution 44 in the portion including the sub-tank 42 is supplied to the membrane pump 46a, the activated carbon filter 47 and the membrane pump 46b, and the filtration filter 48. , And the temperature is detected by a thermocouple 49.

The plating part 43 is shown in detail in FIG.
Are supplied to the wafer (cathode) 50 from below. In the drawing, reference numeral 51 denotes an anode, and a wafer 50 is supported by a nail 52 serving as a cathode. A plating solution 44 flows through a gap between the nails and forms a plating portion as shown in FIGS.
It overflows from 43.

[Problems to be solved by the invention]

However, if bubbles or fine particles are contained in the plating solution, the wafers are mounted in such a way that the plating solution supplied from below is suppressed upward, so that the bubbles and fine particles are easily caught by the resist pattern on the wafer surface. Even if it overflowed, it could not be completely removed. This will be described with reference to FIG. 5. The resin pattern as shown in FIG. 3B is arranged in the plating section 43 as shown in FIG. As shown in FIG. 5 (a), there is no place to escape as shown exaggeratedly in FIG. 5 (a), so that it remains at the corner of the window 34. When plating proceeds in this state, as shown in FIG. 5 (b), plating is performed while the bubbles 53 and fine particles 54 are captured in the plated portion, so that portions with bubbles 53 are plated. It is not, or it is plated while taking in the fine particles 54,
The problem was that defective gold bumps were created.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method of manufacturing a semiconductor device capable of performing good plating without plating while air bubbles and fine particles adhere to a plated portion on a wafer surface.

[Means for solving the problem]

The object is to supply a plating solution (12) from the upper portion of a wafer (11) arranged upward and to cause bubbles (13) and fine particles (14) contained in the plating solution to face the wafer above the wafer. The problem is solved by providing a method for manufacturing a semiconductor device, characterized in that it is removed from a defoaming hole (18) provided and plated.

FIG. 1 is a diagram illustrating the principle of the present invention. In the figure,
11 is a wafer, 12 is a plating solution, 13 is a bubble contained in the plating solution 12, 14 is a fine particle contained in the plating solution 12,
Numeral 11 is arranged upward, and its back surface is in close contact with a vacuum table 15 which is pulled by vacuum. In addition, wafer 11
A plating solution container 16 for supplying the plating solution 12 from above is arranged on the upper side of the substrate. A mesh-shaped platinum (Pt) anode 17 is formed in a portion of the plating solution container 16 facing the wafer 11. The plating solution container 16 is provided with a defoaming hole 18. Reference numeral 19 denotes a cathode-side contact portion provided in the plating solution container 16, which contacts the wafer 11 by contacting the wafer 11.
Is used as a cathode to enable plating.

It is an object of the present invention to provide an
A plating solution 12 is supplied from above, and a mechanism such as a defoaming hole 18 formed in a plating solution container 16 for removing bubbles 13 and fine particles 14 contained in the plating solution 12 from the plating system above the wafer 11 is provided. It is solved by a plating method characterized by comprising.

[Action]

In the present invention, since the plating solution 12 is supplied from above the wafer 11 placed upward, air bubbles are contained in the plating solution 12.
The presence of the particles 13 and the fine particles 14 is removed from the plating system together with the overflowing plating solution 12 from the defoaming holes 19 formed on the upper surface of the plating solution container 18. Therefore, even if the bubbles 13 and the fine particles 14 once adhere to the wafer 11, the plating solution 12 is continuously flowed during the plating, and is eventually removed from the defoaming holes 19 to prevent poor plating.

〔Example〕

Hereinafter, the present invention will be described in detail with reference to an embodiment shown in the drawings.

FIG. 2 is a configuration diagram of a plating apparatus according to an embodiment of the present invention.
Parts corresponding to FIG. 1 are denoted by the same reference numerals.

In the figure, 11 is a wafer, 12 is a plating solution, 15 is a vacuum table for receiving the wafer 11, 16 is a plating solution container 16, 17 disposed above the wafer 11, a platinum (Pt) anode, and 18 is a plating solution container. Defoaming holes formed in 16, and plating solution container 19
16 is a cathode-side contact portion provided in 16. Then, the side surface of the vacuum table 15 is covered with a smooth curved plate to the bottom by the device box 20. This is the plating solution overflowing from the degassing hole 19.
Until the drain 12 reaches the drain portion 21 provided at the bottom of the device box 20, it is prevented from generating unnecessary bubbles. A wafer transfer port 22 is formed at one side of the apparatus box 20, and the wafer 11 inserted from the wafer transfer port 22 is placed upward on the vacuum table 15 and is evacuated. When the wafer 11 comes into close contact with the vacuum table 15, the plating solution container support arm 23 disposed in the apparatus box 20 is provided.
The plating solution container 16 is put on the wafer 11 by the downward movement of the plating solution container 16. At this time, the contact between the cathode side contact portion 19 and the wafer 11,
And the cathode wires 24a and 24b in the plating solution container and the cathode wires 25a and 25b on the vacuum table side, and the anode wires 26 in the plating solution container
It is important that the respective pairs of the anode wiring 27 and the vacuum table side can make good contact. Here, the number of pairs of the cathode wires 24a and 24b and the vacuum table side cathode wires 25a and 25b in the plating solution container may be about three per wafer 11. Further, the number of pairs of the anode wiring 26 in the plating solution container and the anode wiring 27 on the vacuum table side may be one per wafer 11. Until the plating solution container 16 is set, the plating solution 12 is not allowed to flow. When the setting is completed, the plating solution 12 is pumped. The plating solution 12 reaches the surface of the wafer 11 through a flexible material pipe 28 connected to the upper portion of the plating solution container 16, but immediately overflows from the defoaming hole 19. When the defoaming is completed, energize and start plating. When the plating is completed, the flow of the plating solution 12 is stopped, the energization is stopped, the plating solution container support arm 23 is raised, and the wafer 11 may be taken out. Check valve 29 on top of plating solution container 16
Is provided, air does not enter the pipe 28 in the initial state when the plating solution 12 is sent to the next wafer 11, so that the plating solution 12 can be supplied without giving unnecessary bubbles.

According to the above-described plating method, the plating solution 12 is supplied from the plating solution container 16 above the wafer 11 placed upward on the vacuum table 15, so that bubbles 13 and fine particles are contained in the plating solution 12. When the plating solution 14 is present, the plating solution 12 is removed from the plating system together with the overflowing plating solution 12 from the defoaming hole 19 formed on the upper surface of the plating solution container 16. Therefore, even if the bubbles 13 and the fine particles 14 adhere to the wafer 11 once, the plating solution 12 is continuously flowed during plating, and is eventually removed from the defoaming hole 19 to eventually remove the bubbles 13 and the fine particles 14 from the plating portion. The plating is not performed with the captured state, and defective plating is less likely to occur.

In the present invention, the plating solution is supplied from above the wafer placed upward, and the plating solution is removed from the plating system by removing bubbles and fine particles from the plating system together with the plating solution provided above and overflowing from the defoaming holes. do it.

〔The invention's effect〕

As described above, according to the present invention, a plating solution is supplied from above a wafer placed upward, and bubbles and fine particles are removed along with a plating solution overflowing from a defoaming hole formed on an upper surface of a plating solution container. By removing from the surface, there is an effect that plating is not performed while bubbles and fine particles remain in the resist pattern on the wafer surface, and a good bump can be formed, which greatly contributes to improvement in yield.

[Brief description of the drawings]

FIG. 1 is a view for explaining the principle of the present invention. FIG. 2 is a structural view of a plating apparatus according to an embodiment of the present invention. FIGS. 3 (a) to 3 (c) are cross-sectional views showing a method of forming a gold bump. FIG. 5 (a) and 5 (b) are cross-sectional views showing the problems of the conventional example. In the figure, 11 is a wafer, 12 is a plating solution, 13 is a bubble, 14 is a fine particle, 15 is a vacuum table, 16 is a plating solution container, 17 is a platinum (Pt) anode, 18 is a defoaming hole, and 19 is a cathode side contact. Part, 20 is an equipment box, 21 is a drain part, 22 is a wafer loading port, 23 is a plating solution container support arm, 24a and 24b are cathode wires in the plating solution container, 25a and 25b are cathode wires on the vacuum table side, 26 is Anode wiring in plating solution container, 27 is vacuum table side anode wiring, 28 is piping, 29 is check valve, 41 is main tank, 42 is sub tank, 43 is plating part, 44 is plating solution, 45 is magnet pump, 46a and 46b are membrane pumps, 47 is an activated carbon filter, 48 is a filter, 49 is a thermocouple, 50 is a wafer (cathode), 51 is an anode, and 52 is a nail.

Claims (1)

(57) [Claims] 1. A plating solution (12) is supplied from the upper part of a wafer (11) arranged upward, and bubbles (13) and fine particles (14) contained in the plating solution are removed from the wafer above the wafer. A method of manufacturing a semiconductor device, comprising removing and plating from defoaming holes (18) provided to face each other.