JPS5827021Y2 - Jet plating device - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a jet plating apparatus for plating an electrode, etc. on one side of a semiconductor wafer, and its main purpose is uniform plating.

Generally, methods such as AI vapor deposition and Ag plating are used to form electrodes of semiconductor devices such as diodes and transistors.

For example, when forming an electrode layer on the entire back surface of a wafer, a jet plating method is often used.

An example of conventional equipment for this jet plating method is shown in Figure 1.
is a wafer, 2 is a negative upper plating electrode, 3 is a positive lower plating electrode, 4 is a wafer support, 5 is a plating inner cylinder to which the wafer support 4 is fixed, 6 is a plating outer cylinder, 7
is a circulation pipe, 8 is a pump, and 9 is a plating solution such as Ag.

In the plating operation with the above configuration, the first wafer 1 is supported from the back side with the wafer support 4, and then the upper plating electrode 2
The wafer 1 is fixed by bringing it into contact with the back surface of the wafer 1.

In this state, the pump 8 is operated, and the plating liquid 9 is jetted out from the plating inner cylinder 5 toward the back surface of the wafer.

Then, the plating solution 9 hits the back surface of the wafer and flows out laterally and radially along the back surface.

During this time, by applying voltage to each plating electrode 2, 3, Ag
Ions and the like are plated on the back surface of the wafer 1.

Furthermore, the plating solution 9 flowing out from the back side of the wafer 1 flows into the plating outer cylinder 6 over the plating inner cylinder 5, is collected in the circulation pipe 7, and is again transferred from the plating inner cylinder 5 to the back side of the wafer by the pump 8. It is ejected towards the target.

By the way, as plating continues with this conventional device, bubbles 10 that are created when the plating liquid 9 flows from the inner plating cylinder 5 to the outer plating cylinder 6 pass through the circulation pipe 7 and pump 8 and are removed from the inner plating cylinder 5. Sprayed onto the backside of the wafer.

Then, since the conventional wafer 1 is in a fixed state, the bubbles 10 rarely flow out along the back surface of the wafer together with the plating solution 9, and some of the bubbles 10 adhere to the back surface of the wafer as shown in FIG. However, it sometimes attached itself and grew large.

When air bubbles 10 adhere to the back surface of the wafer in this way, the growth of the plating is delayed in the area where the air bubbles are attached, and the thickness of the plating layer 11 becomes uneven.The wafer 1 is subdivided into pellets, resulting in defective back electrodes. This had the disadvantage of reducing yield.

The present invention improves and eliminates the above-mentioned conventional drawbacks, and provides a jet plating apparatus that prevents air bubbles from adhering to the back surface of a wafer by plating while rotating the wafer.

Hereinafter, the configuration of the present invention will be explained with reference to the drawings.

In FIG. 3, 12 is an upper plating electrode, 13 is a lower plating electrode, 14 is a plating inner cylinder, 15 is a plating outer cylinder, 16 is a circulation pipe, 17 is a pump, and 18 is a plating solution.

In contrast to these configurations, in the present invention, the mechanism for holding the wafer 1 is performed using the following wafer holding jig 19.

That is, the wafer holding jig 19 includes a holding claw 20 that contacts the back surface of the wafer 1 and holds the wafer 1 horizontally, a support rod 21 that fixes the holding claw 20 at the tip, and a support rod 21 that is attached to the circumferential surface of the support rod 21. The support rod 21 is rotatably supported by a screw 22 formed in a helical shape and the upper and lower portions of the support rod 21, respectively.
A support arm 23 that supports the plated inner cylinder 14 on the center line
．． It consists of 24.

Note that the lower plating electrode 13 is arranged below the support rod 21,
Furthermore, the plating solution 18 is applied to the lower plating electrode 13 and the support arm 2.
3. It should be configured so that it can easily pass between 24 and eject upward.

In this case, the lower plating electrode 13 may be constructed of a mesh-like electrode.

Further, the upper plating electrode 12 has a structure in which it contacts the surface of the wafer 1 and applies a voltage, and in the case of the present invention, its tip is provided so as to be freely rotatable so as to follow the rotation of the wafer 1.

Next, a plating operation procedure using the above configuration will be explained.

The wafer 1 is placed on the holding claw 20 of the wafer holding jig 19.
The upper plating electrode 12 is brought into contact with the surface of the wafer 1, and the wafer 1 is held from above and below.

At this time, the center of the upper plating electrode 12 is placed on the center line of the support rod 21 of the wafer holding jig 19.

After that, a voltage is applied to the upper plating electrode 12 and the lower plating electrode 13, the pump 17 is operated, and the plating liquid 18 is jetted from the plating inner cylinder 14 toward the back surface of the wafer.

Then, the plating solution 18 rises between the support arms 23 and 24, and part of it hits the screw 22 of the support rod 21 and rises.

That is, the spouting plating solution 18 rotates the support rod 21 via the screw 22, and by the rotation of the support rod 21,
The wafer 1 also rotates via the holding claws 20.

Then, the back surface of the wafer is plated with a plating solution 18 that is spouted while rotating.

Further, during the plating, the plating liquid 18 flowing out from the outer periphery of the back surface of the wafer passes through the inner plating cylinder 14 and flows into the outer plating cylinder 15, and is ejected to the back surface of the wafer together with the bubbles 25 formed here.

If the bubbles 25 are attached to the back surface of the wafer 1 as shown in FIG. 4, the bubbles 25 rotate with the rotation of the wafer 1 and move outward due to the centrifugal force. Finally, it is removed from the outer periphery of the back surface of the wafer.

Further, as the wafer 1 rotates, centrifugal force acts on the plating liquid 18 flowing along the back surface of the wafer, and the plating liquid 18 flows out strongly to the outside, so that the plating liquid 18 does not flow around to the side surface or the front surface of the wafer 1.

In addition, the flow of the plating solution 18 is strengthened by rotating the wafer.1. The rate at which bubbles 25 adhere to and stagnate on the wafer surface is reduced.

Although the wafer holding jig 19 has a simple structure in which the wafer 1 is rotated by using the flow of the plating solution 18 by using the screw 22, the structure is not limited to this. Regardless of the flow of 18,
It may be rotated from the outside using a motor or the like.

Further, a wafer rotation mechanism may be attached to the side of the upper plating electrode 12 which also serves to hold the wafer 1.

As explained above, the present invention has a wafer holding jig that rotatably holds the wafer in a plating apparatus that sprays plating liquid onto the wafer held along the plating liquid level, and the wafer is held in place during plating. By rotating the plating solution, air bubbles in the plating solution are less likely to adhere to the wafer, and even if they do, they can be easily removed by rotating the wafer, ensuring uniform plating on the entire surface of the wafer and eliminating defective pellets. Decrease.

Furthermore, the rotation of the wafer prevents the plating solution from flowing around to the side surface or surface of the wafer, making it possible to perform jet plating with high reliability.

[Brief explanation of the drawing]

FIG. 1 is a side sectional view of a conventional jet plating apparatus, FIG. 2 is a sectional view of the wafer plating surface by the conventional apparatus, FIG. 3 is a side sectional view showing an embodiment of the apparatus according to the present invention, and FIG. The figure is a sectional view of the plating operation on the wafer plating surface according to the present invention. 18...Plating solution, 19...Wafer holding jig.

Claims (1)

[Scope of utility model registration request] A plating device that sprays a plating solution onto a wafer held along the plating solution surface is characterized by having a wafer holding jig that rotatably holds the wafer so that the wafer can be rotated during plating. Jet plating equipment.