JP3514364B2 - Jet plating equipment - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a jet plating apparatus, and in particular, it is possible to perform uniform plating over the entire surface of a large-diameter wafer. The present invention also relates to a jet-type plating apparatus in which a jet speed is increased to prevent so-called microbubble stagnation. 2. Description of the Related Art In general, a semiconductor device is formed on a disk-shaped wafer in such a manner that a large number of semiconductor devices are collectively formed, cut into individual elements, and then electrodes formed on the semiconductor are formed. It is used by connecting to the lead by wire bonding or the like. At this time, the portion to be wire-bonded may not be able to secure a sufficient connection with the wire unless it has a certain thickness, and the bump electrode is directly connected to the lead without using wire bonding. In such a case, a thicker electrode is required. [0003] From such a demand, the bump electrode is formed by plating a good conductor such as gold thickly.
FIG. 3 shows a part of a manufacturing process of such a semiconductor device 30 . FIG. 1B shows a state in which a plurality of semiconductor devices 30 are collectively formed on a semiconductor wafer, and a bump electrode 31 is formed on each of the semiconductor devices 30 . The semiconductor device 30 on which the bump electrodes 31 are formed in this manner is individually cut off from the semiconductor wafer 34 , and the bump electrodes 31 are wire-bonded to the leads 32 with wires 33 as shown in FIG. Connected and put to practical use. The bump electrodes are generally formed in a large number of rows on the outer peripheral portion of the semiconductor device. At present, the number of the bump electrodes is large in order to satisfy the demands of a semiconductor device with higher performance. And the pitch of the bump electrodes is as small as 50 microns or less. In addition, in order to reliably perform wire bonding or in recent years, a method of connecting leads directly to bump electrodes without using wire bonding, which is a new method of connecting leads to semiconductor devices, requires a sufficient thickness of bump electrodes. And its thickness is about 20 to 50 microns, which is much larger than the conventional one. Also, the length and width of the bump electrode have been reduced. FIG. 4 is a diagram for further explaining a bump electrode.
It is. 4 (a) is a representation with a state of a semiconductor device actually bump electrodes 41 formed on the outer peripheral portion of the chip in a perspective view. As described above, since the bump electrodes 41 are formed continuously with the outer peripheral portion of the element of the semiconductor device 42 and a large number of bump electrodes must be formed, the pitch at which the bump electrodes are formed is becoming smaller. Also, as shown in FIG. 2B, the height of the electrode is required to be very high, while the length and width of the electrode are at most 50.
Extremely small ones, such as on the order of microns, have been required. [0006] Therefore, the aspect ratio of the bump electrode is gradually increasing, and as described in the subject to be described later, plating thereof is becoming difficult. FIG. 5 shows a conceptual diagram of plating of a bump electrode including the conventional method.
It was shown to. Referring briefly to FIG. 5 , plating is performed by converting positively charged metal ions 51 in a plating solution to a wafer 52.
The metal ions 51 are formed by laminating and growing in the plating growth area formed on the conductive land 53.
, A negative potential is applied, and the potential difference caused by the negative potential causes the layers to be concentratedly stacked on a predetermined plating area. On the other hand, an anode 54 is formed in the plating solution, and the anode 54 and the positively charged metal ions 5 are formed.
A closed current circuit is formed by 1 and the plating region, and the plating is continuously grown without interruption. In particular, when the plating region grows on the semiconductor wafer, the plating region is distinguished from the undesired plating region by the resist 55. When the plating region is covered by the resist 55 , the plating does not grow. These series of operations are performed in the plating bath 56, typically being a large, jet plating. Next, a conventional jet plating apparatus will be briefly described with reference to the drawings. FIG. 6 shows a conventional jet plating apparatus. The feature of the jet plating apparatus 60 is that a plating jet is applied at a high flow rate to the surface side of a wafer 61 , which is a plating growth surface, to form a plating flow at a high speed on the wafer surface, thereby forming a plating solution 62 on the wafer surface. It is intended to always exchange metal with a new one and supply metal cations without interrupting the growth of plating to achieve uniform growth of the plating film. That is, the jet is applied to the plating growth area of the wafer in order to always supply a fresh plating solution 62 to the plating growth area. For this purpose, the plating solution is pumped from the bottom of the jet cup 63 by the pump 64. 62 is a wafer 61
Plating solution sprayed with a jet
The plating solution 62 flows out of the hole 65 formed in the side surface of the jet cup 63 to the outside, and the plating solution 62 flowing to the outside is received by the surrounding container in which the jet cup 63 is stored, and is collected again toward the pump 64. Then, it is repeated that the liquid is sprayed again by the jet 64 onto the surface of the wafer 61 by the pump 64 . Problems to be solved by the invention will be described below. With the recent increase in the diameter of the wafer, a wafer having a diameter of 3 to 4 inches has conventionally been sufficient.
In some cases, uniform plating of bump electrodes or the like must be performed on a wafer having a diameter of 10 to 10 inches. In such a case, the difference in the flow rate of the plating solution between the central portion of the wafer and the edge portion of the wafer affects the growth of plating. 7 (a) is the wafer 70 diameter 3 to be processed
4 bump electrode 71 from the central portion of the wafer 70 as shown in the same time changes 5-10 inches inches FIG (b) is formed over an end portion of the wafer 70
This shows how the height changes. When the height of the bump electrodes 71 changes in this manner, the wafer 70 is cut out, and when each becomes a chip of a semiconductor device, the height of the bump electrode 71 varies for each chip of each semiconductor device. The conditions at the time of wire bonding or the conditions at the time of directly pressing and connecting to the leads are not the same, and the manufacturing conditions between one lot cannot be made constant, which is a problem in the manufacturing process. [0012] In order to solve the above-mentioned problems,
The invention according to claim 1 provides a jet cup body and a wafer holder.
A jet-type plating apparatus comprising:
The rudder is separated upward from the opening surface of the jet cup body.
And place the wafer, and the wafer holder
Ring base with rubber
And the jet cup body extends along its opening edge.
Rectification of plating solution overflowing from this opening outward
It is a jet plating apparatus characterized by having a weir.
Large-diameter by having such a plating solution rectifying weir
The phased plating velocity of the central portion and the peripheral portion component of the wafer Hitoshi
It becomes possible to unify. [0013] The invention according to claim 2 is the invention according to claim 1.
In the jet plating apparatus of the above, the jet cup body,
Consisting of a cup and a frame surrounding the cup,
The frame-shaped body forms the rectifying weir described above.
It is a jet plating apparatus. [0014] The third aspect of the present invention is the second aspect of the present invention.
In the above jet-type plating apparatus, the frame-shaped body is
It is characterized by being removable from the flow cup body
A jet-type plating apparatus according to claim 2. Take this way
It can be easily removed, so that one frame can be
It becomes easy to exchange for the body. Then, for example,
Plating process such as adjusting the outer shape of the rectifying weir according to the flow velocity
Design becomes easier. DETAILED DESCRIPTION OF THE INVENTION The present invention FIG. 1 (a),
(B) explains the effect. 1 (a) is a conventional jet-type plating apparatus 10. On the other hand, FIG. 2B shows a jet plating apparatus 12 having a rectifying weir 11 which is a feature of the present invention. Plating flow velocity in the central part of the wafer 13 in the case of a not have a rectifying weir as shown in the diagram (a) is can be seen from the flow velocity distribution shown below the sectional view is that large diameter is faster but the periphery As it goes to the section, its flow rate gradually decreases. [0016] However the figure along the opening edge of the jet cup body 14 as shown in (b) rectifying the outside weir 11
In this case, the flow velocity can be made uniform over the entire wafer 13 having a large diameter. As a result, the flow velocity can be made uniform over the entire area of the wafer 13 having a large diameter.
This is because the flow rate of the plating at the outermost peripheral portion when flowing into the surrounding container from 14 can be reduced, so that the flow rate can be made uniform while securing the plating flow rate as a whole. This has increased the diameter in recent years
The center of the wafer and the edge of the wafer
Since the difference in plating solution flow rate between
The height of the electrode is between the center of the wafer and the edge of the wafer.
The difference almost disappears. Increase the size (capacity) of the jet cup body
Even at the center of the wafer and the edge of the wafer,
It is possible to reduce the difference in the flow rate of the liquid. However, simply enlarging the size of the jet cup body results in the use of a large amount of expensive plating solution, which is disadvantageous in terms of cost. it is had to have a rectification weir on the outside along the opening edge as in the invention of claim 1, wherein in order but ¥ the same effect as the jet cup body is large. Next, the third aspect of the present invention will be described. According to the third aspect of the present invention, the jet cup body is a jet plating apparatus which comprises a cup and a frame surrounding the cup, the frame forming a flow regulating weir and being detachable from the cup. . FIG. 2 is a partial sectional view of the present invention. As can be seen in FIG. 2 , the jet cup body 21 has two parts. The first part is a cup 21a into which the plating solution is filled and a plating flow is sent from the bottom, and the second part is a frame 21b arranged so as to surround the cup 21a . This frame
The great function of 21b is to form a rectifying weir. The upper end portion of the frame 21b is formed substantially flush with the opening surface of the cup as shown, and the plating solution overflowing from the opening edge of the cup 21a is surrounded by the upper outer edge of the frame 21b. It will overflow into the container. Accordingly, the frame 21b functions as a rectifying weir. On the other hand, another feature of the present invention is that the frame 21b forming the rectifying weir is detachable from the cup. It is easy to replace the frame body 21c showing the frame body 21b shown in FIGS. 2 (a) in FIG. (B) By the way, a detachable. This facilitates the design of the plating process, such as adjusting the outer diameter of the rectifying weir according to the plating flow rate. According to the present invention , along the opening edge of the jet cup body,
If there is a rectifying weir on the side, the whole wafer becomes larger
Can be made uniform. This
Even with recent large-diameter wafers,
The difference in plating solution flow rate between the edge of the wafer and the
Therefore, the height of the bump electrode is
There is almost no difference between the end portion and the end portion.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view of a main part of a jet plating apparatus of the present invention . FIG . 2 is a view showing an example of a frame-shaped body of the present invention. FIG. 3 is a conceptual view showing a configuration of a semiconductor device. FIG. 4 is a view showing bump electrodes formed on a semiconductor device. FIG . 5 is a conceptual view of plating of bump electrodes. FIG. 6 is a cross-sectional view of a conventional jet plating apparatus. FIG. 7 is a diagram showing wafer diameter and plating of bump electrodes. Height relationship
DESCRIPTION OF SYMBOLS 10 jet type plating apparatus 11 rectifying weir 12 jet type plating apparatus 13 wafer 14 jet cup body 21 jet cup body 21 a cup 21 b frame 21 c frame 30 semiconductor device 31 bump electrode 32 lead 33 Wire 34 Semiconductor wafer 41 Bump electrode 42 Semiconductor device 51 Metal ion 52 Wafer 53 Conductive land 54 Anode 55 Resist 56 Plating tank 60 Jet plating apparatus 61 Wafer 62 Plating solution 63 Jet cup 64 Pump 65 hole 70 Wafer 71 Bump electrode

Continuation of the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) H01L 21/288 C25D 5/08

Claims (1)

(57) [Claims] [Claim 1] Consisting of a jet cup body and a wafer holder
A jet plating apparatus, wherein the wafer holder is
The wafer is separated upward from the opening surface of the
Placing said wafer holder to receive the outer peripheral edge of the wafer
A portion having a ring base made of rubber;
The jet cup body should be open outwards along its opening edge.
A rectifying weir for the plating solution that overflows from
The flow cup body is a cup and a frame that surrounds the cup
The frame-shaped body forms the rectifying weir,
The frame is detachable from the jet cup body.
Jet plating apparatus characterized by the following .