JPH07243097A - Wafer plating rack and plating method using the rack - Google Patents

Abstract

PURPOSE:To reduce the amt. of a plating soln. to plate a wafer, to miniaturize the whole device and to simplify the device elements such as the plating tank and plating soln. feed mechanism at the time of plating wafers. CONSTITUTION:A rack 1 for plating wafers to be used is fabricated by combining the semiannular frame members 5 each having two holding grooves 4 on its inner periphery and made rotatable, openable and closable. A set of two wafers W are coupled back to back with the front to be plated out and held by the rack 1, and hence two wafers are simultaneously treated with one rack 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for plating a semiconductor wafer.

[0002]

2. Description of the Related Art When a wafer is subjected to a plating treatment such as bump plating, it is an important element to selectively bring only the surface to be plated into contact with a plating solution. Therefore, conventionally, a plating system having a basic structure as shown in FIG. 5 is generally used. In this system, a cup-shaped jetting tank 21 which also serves as a supporting means for the wafer W is provided in the plating tank 20, and the upper end of the jetting tank 21 is covered with the wafer W with the surface to be plated facing downward. In this state, the plating solution is supplied in a jet form from the heating tank 22 through the circulation pipe 23 in this state, and the plating solution M supplied to the jet tank 21 is a wafer W. And a flow spreading to the periphery while forming contact with the surface to be plated and flowing out into the plating tank 20 (for example, Japanese Utility Model Publication No. 58-8774, Japanese Utility Model Publication 3-19).
70, Japanese Utility Model Publication No. 4-44371, etc.).

As can be seen from the above, the conventional system can process only one wafer per injection tank. This is a matter of processing efficiency,
In particular, it causes a problem that a large amount of plating solution is used for each wafer, and in order to efficiently process a large amount of wafers, a large number of injection tanks must be provided side by side, and therefore the entire apparatus is required. Has also brought the problem of becoming larger.

Further, in the conventional system, since it is necessary to jet and supply the plating solution into the jetting tank, the device elements such as the plating tank and the plating solution feeding mechanism are complicated.
This is not only a factor for increasing the size of the entire apparatus, but also requires a fixed arrangement of the apparatus, which hinders efficient use of the factory space.

[0005]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to allow two wafers to be processed by being supported by one supporting means, specifically, a rack, so that plating per wafer can be performed. It is intended to reduce the amount of liquid used, downsize the entire apparatus, and simplify the apparatus elements such as a plating tank and a plating solution supply mechanism.

[0006]

To this end, according to the present invention, semi-annular frame members each having two holding grooves formed on the inner peripheral surface thereof are rotatably combined at one end thereof. Has a frame body formed in an annular shape similar to the outer periphery of the wafer to be held, and the respective peripheral portions are fitted to the annular holding grooves formed by combining the holding grooves of both frame members in this frame body. By using a plating rack having a structure in which two sets of wafers are held back to back with the surfaces to be plated on the front side, the plating rack holding two sets of wafers is used. The rack is immersed in the plating solution in the plating tank, and in this immersion state, the plating solution is brought into fluid contact with the surface to be plated of each front side wafer to perform plating.

According to the present invention as described above, since one wafer can process two wafers at the same time, the wafer 1
The amount of plating solution used per plate can be significantly reduced, and the device size per processing capacity can be reduced.

Further, according to the present invention, the plating solution is brought into contact with the wafer while the plating rack is immersed in the plating solution in the plating tank. Therefore, the device elements such as the plating tank and the plating solution supply mechanism can be greatly simplified.

Regarding the point of giving the flow state of the plating solution to the wafer without jetting and supplying the plating solution, a method of stirring the plating solution in the plating tank is also possible, but the plating rack is placed in the plating solution. How to rotate is
It is more preferable in that a higher distribution of the flow distribution of the plating solution on the surface to be plated can be obtained.

Further, according to the present invention, in the plating rack as described above, the tip of the electrode terminal is provided so as to project on the inner wall of the holding groove, and the electrode terminal is fitted when the peripheral portion of the wafer is fitted in the holding groove. The resist film of the corresponding portion is scraped off at the tip of the wafer so that the wafer can be energized.
This utilizes the structure in which the peripheral edge is fitted into the holding groove to hold the wafer, and as a result, it is essential for stable plating treatment and for wafers that have been conventionally required various innovations. Energization of the cathode can be ensured easily and reliably.

[0011]

EXAMPLES An example of the present invention will be described below.
As shown in FIGS. 1 and 2, the plating rack 1 according to the present embodiment has a rotational force transmitting portion 3 connected to a frame body 2 formed in an annular shape similar to the outer periphery of a wafer W to be held. ing.

The frame 2 is formed by connecting a pair of semi-annular frame members 5 and 5 each having two holding grooves 4 and 4 on the inner peripheral surface thereof so as to be rotatable at one end of each other. , Wafer W
In order to attach / remove the device, it can be rotated and opened as shown by an imaginary line in the figure. Further, as shown in FIG. 3, the tip ends of the cathode electrode terminals 6 are slightly protruded from the inner side walls of the holding grooves 4 and 4 of each frame member 5 so as to be elastically retractable.

To hold the wafer W on the plating rack 1, first open both frame members 5, 5 as described above,
Therefore, the wafers W and W are sandwiched between the frame members 5 and 5 so that the surfaces to be plated are outside each other, and then the frame members 5 and 5 are closed. Then, each wafer W is held by the frame body 2 in a state in which the peripheral edges of the respective wafers W are fitted in the holding grooves 4, 4 of both the frame members 5, 5. At this time, the peripheral edge of the wafer W is rubbed by pushing the tip of the electrode terminal 6 into the inner side wall of the holding groove 4, and as a result, the resist film applied thereto is scraped off by the tip of the electrode terminal 6. As a result, a conductive state between the electrode terminal 6 and the wafer W is obtained.

Both wafers W thus held,
The back side of W is completely sealed with the plating solution, and when the rack 1 is immersed in the plating solution M in the plating tank 7 as shown in FIG. It is possible to selectively contact only the plating solution M.

The plating process using such a plating rack 1 proceeds while gently rotating the plating rack 1 immersed in the plating solution M in the plating tank 7 as shown in FIG. In order to rotate the plating rack 1, a rotational force is transmitted from a drive system (not shown) via the rotational force transmission section 3, but a generally known mechanism can be used as the mechanism. And the illustration is omitted.

Generally, the plating solution M needs to be heated, but in this example, indirect heating by a hot bath system is used. That is, the plating bath 7 is immersed in the hot bath 8 filled with the heating liquid L to heat the plating liquid M in the plating bath 7.

[0017]

As described above, according to the present invention, one rack can process two wafers at the same time.
The amount of plating solution used per wafer can be significantly reduced, the equipment size per processing capacity can be reduced, and there is no need to supply the plating solution by jetting as in the conventional method. It is possible to greatly simplify the device elements such as the liquid supply mechanism.

[Brief description of drawings]

FIG. 1 is a side view of a plating rack according to the present invention.

FIG. 2 is a sectional view taken along the line SA ₂ —SA _{2 in} FIG.

FIG. 3 is a cross-sectional view showing a state where the electrode terminals are assembled in the holding grooves of the frame member.

FIG. 4 is a sectional view showing a state of a plating process using the plating rack of FIG.

FIG. 5 is a block diagram of a conventional plating system.

[Explanation of symbols]

 1 Plating rack 2 Frame 3 Rotational force transmission part 4 Holding groove 5 Frame member 6 Electrode terminal 7 Plating tank M Plating solution W Wafer

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location C25D 7/12 H01L 21/68 N 21/321

Claims (4)

[Claims] 1. A rack for plating a wafer, which holds a wafer in a state where a surface to be plated is selectively brought into contact with a plating solution, comprising a semi-annular frame member having two holding grooves formed on an inner peripheral surface thereof. To have a frame body formed in an annular shape similar to the outer periphery of the wafer to be held by being rotatably combined at one end of each other, and fitting the respective peripheral portions to the respective holding grooves of both frame members in this frame body 2. A rack for plating a wafer, characterized in that a set of two wafers is held back to back with the surfaces to be plated on the front side. 2. The wafer is provided by projecting the tip of an electrode terminal on the inner wall of the holding groove, and scraping off the resist at the corresponding portion at the tip of the electrode terminal when fitting the peripheral edge of the wafer into the holding groove. Claim 1 which can energize electricity to
The described rack for plating. 3. A plating method for plating a wafer using the plating rack according to claim 1 or 2, wherein the plating rack holding a set of two wafers is plated in a plating tank. A plating method in which a plating solution is immersed in a liquid and the surface of each wafer to be plated is brought into fluid contact with the plating solution to perform plating. 4. The plating method according to claim 3, wherein the plating rack is rotated to impart a flow state of the plating solution to the wafer.