JPH062192A - Plating device - Google Patents

Abstract

PURPOSE:To improve the intrasurface uniformity of plating thickness when a substrate to be plated is plated in a jet stream type plating device by providing a heater for heating the whole or a part of the rear of a substrate to be plated. CONSTITUTION:A plating liquid 6 heated to a constant temp. by a heater 4 in a plating vessel 1 is made to flow down by a circulating pump 3 into a plating vessel 1 from a jet hole 5 through a jet stream part 2 to give plating to the plating surface of a substrate to be plated 9 provided on a cathode pin 8. At this time, a substrate heating part 10 is provided on the rear of the substrate to be plated 9 to heat the whole or a part of the rear of the substrate so that the substrate may be about 10 deg.C higher than the temp. of the plating liquid. As a result, the intrasurface uniformity of plating thickness is improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plating apparatus, and more particularly to a jet type plating apparatus used for manufacturing a semiconductor device having a thin film fine pattern.

[0002]

2. Description of the Related Art In recent years, semiconductor devices have been used not only in information and communication equipment but also in all household electric appliances, and their high performance has been remarkable. Most of the semiconductor devices are Si devices, but recently, GaAs semiconductor devices have attracted attention as high-speed and high-frequency devices. It has already been put to practical use as a device for satellite broadcasting and a device for mobile phones, and is expected to be applied in all fields in the future. Since a GaAs device does not impair the high-speed and high-frequency characteristics that are characteristic of GaAs, a low resistance thick film Au wiring is used for the wiring, and the selective plating method is generally widely used. In the selective plating method, a base metal thin film is formed on the entire plating surface of a substrate to be plated, and a desired wiring pattern is formed by a photoresist removal pattern, and then plating is performed to form plating in the wiring pattern. After that, the underlying metal thin film other than the photoresist and the plated portion is removed to form a desired plated wiring. Here, as a plating apparatus for forming the plated wiring, a jet-type electrolytic plating apparatus is widely used.
FIG. 7 shows a schematic sectional view of a conventional jet-type plating apparatus.
In FIG. 7, 21 is a plating tank, 22 is a jet part, 23 is a circulation pump, 24 is a heater for heating the plating solution, 25 is an ejection port, 26 is a plating solution, 27 is an anode electrode, 2
Reference numeral 8 is a cathode pin, and 29 is a substrate to be plated.

The plating liquid 26 heated to a constant temperature by the heater 24 in the plating tank 21 flows through the jet part 22 by the circulation pump 23 and flows down into the plating tank 21 from the ejection port 25. The plating is performed by placing the substrate 29 to be plated with the plating surface facing downward on the cathode pin 28 and applying an electric current between the anode electrodes 27 provided in the jet portion 22.

[0004]

In the jet-type plating apparatus as shown in FIG. 7, it is difficult to control the variation of the plating thickness within the substrate, and the film thickness is often concentric. Figure 8
Shows the variation in the plating thickness in the inner diameter direction of the wafer surface when the Au wiring was plated on the 3-inch GaAs substrate so that the target plating thickness was 1.5 μm. In the figure, (a), (b) and (c) show variations when the flow rate of the plating solution is changed to 1 liter / min, 2 liter / min and 3 liter / min, respectively. As a result, when the flow rate of the plating solution is changed, the variation in film thickness slightly changes, but the distribution shape is almost the same. This means that the flow of the plating solution is poor around the wafer and the plating thickness is small. On the other hand, in the central part of the wafer, the flow of the plating solution is good and the plating thickness is large. The difference in the plating thickness depending on the plating solution amount in the central portion is due to the difference in the solution flow rate on the plating surface. Further, the lower the flow rate is, the smaller the variation is, but if the flow rate is further reduced, different problems such as roughening of the plating surface occur and the flow rate is limited.

The present invention provides a plating apparatus capable of improving the in-plane uniformity of the plating thickness by heating the back surface of the substrate to be plated and providing a flow rate adjusting plate for adjusting the flow rate of the plating solution. The purpose is to

[0006]

In order to solve the above problems, the present invention provides a jet type plating apparatus having a heating portion for heating the whole or a part of the rear surface of a substrate to be plated.
Further, the present invention comprises a jet flow type plating apparatus having a flow rate adjusting unit for adjusting the flow of the plating liquid on the surface of the substrate to be plated.

[0007]

As described above, the present invention has a heating unit for heating the whole or a part of the back surface of the substrate to be plated in the jet plating apparatus, and a flow rate adjusting unit for adjusting the plating liquid flow on the surface of the substrate to be plated. By including it, the in-plane uniformity of the plating thickness can be improved.

[0008]

EXAMPLE FIG. 1 shows a first example of the plating apparatus of the present invention. In FIG. 1, 1 is a plating tank, 2 is a jet unit, 3 is a circulation pump, 4 is a heater for heating a plating solution, 5 is an ejection port, 6 is a plating solution, 7 is an anode electrode, 8 is a cathode pin, and 9 is The substrate 10 to be plated is a substrate heating unit.
The substrate heating unit 10 is for directly heating the substrate to be plated from the back surface of the substrate 9 to be plated. A 3-inch GaAs wafer was plated with a thickness of 1.5 μm using this plating apparatus. The shape of the substrate heating unit 10 at this time is to heat the outer circumference 10 mm of the 3-inch wafer, and the temperature was 70 ° C., which is 10 ° C. higher than the plating solution temperature 60 ° C. FIG. 2 shows the variation of the plating thickness in the surface inner diameter direction at this time. From the figure, it can be seen that the plating thickness around the wafer is increased and the uniformity is improved. This is because the plating rate was increased by heating the peripheral portion of the wafer. FIG. 3 shows the liquid temperature dependence of the plating rate. In the case of the jet-type plating apparatus, the uniformity can be further improved by increasing the heating temperature from the center of the substrate to be plated toward the outer peripheral portion.

FIG. 4 shows a second embodiment of the plating apparatus of the present invention. In FIG. 4, 11 is a plating tank, 12 is a jet part,
13 is a circulation pump, 14 is a heater for heating the plating solution,
Reference numeral 15 is an ejection port, 16 is a plating solution, 17 is an anode electrode, 18 is a cathode pin, 19 is a substrate to be plated, and 20 is a flow rate adjusting unit of the plating solution. The flow rate adjusting unit 20 is installed between the substrate to be plated 19 and the ejection port, and the substrate to be plated 1
It is for adjusting the amount of plating solution corresponding to 9. 1.5 μm on 3-inch GaAs wafer with this plating equipment
It was thickly plated. As shown in FIG. 5, the shape of the flow rate adjusting portion 20 at this time is a thin plate formed with a large number of holes so that the density becomes higher from the center toward the outer periphery. FIG. 6 shows the variation of the plating thickness in the surface inner diameter direction at this time. From the figure, it can be seen that the uniformity is improved. This is because the flow rate adjusting section 20 makes the flow of the plating solution uniform on the surface of the substrate to be plated and improves the uniformity.

In the present embodiment, the case where the substrate heating portion is a part of the substrate has been described, but this is not limited to this portion and may be the entire surface. Further, in the present embodiment, the flow rate adjusting portion is described as a thin plate having many holes, but the flow rate adjusting portion is not limited to this and may have another shape.

[0011]

As described above, the jet plating apparatus according to the present invention has a heating part for heating the whole or a part of the back surface of the substrate to be plated, and adjusts the plating liquid flow on the surface of the substrate to be plated. By providing the flow rate adjusting section, it is possible to improve the in-plane uniformity of the plating thickness.

[Brief description of drawings]

FIG. 1 is a diagram showing a first embodiment of the present invention.

FIG. 2 is a characteristic diagram showing the effect of the present invention.

FIG. 3 is a characteristic diagram showing the effect of the present invention.

FIG. 4 is a diagram showing a second embodiment of the present invention.

FIG. 5 is a diagram illustrating a second embodiment of the present invention.

FIG. 6 is a characteristic diagram showing the effect of the present invention.

FIG. 7 is a diagram illustrating a conventional plating apparatus.

FIG. 8 is a characteristic diagram showing characteristics of a conventional plating apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Plating tank 2 Jet part 3 Circulation pump 4 Heater for heating plating liquid 5 Spouting port 6 Plating liquid 7 Anode electrode 8 Cathode pin 9 Plated substrate 10 Heating part 11 Plating tank 12 Jet part 13 Circulation pump 14 Heater for heating plating liquid 15 Spouting port 16 Plating liquid 17 Anode electrode 18 Cathode pin 19 Plated substrate 20 Liquid amount adjusting part 21 Plating tank 22 Jet flow part 23 Circulation pump 24 Plating liquid heating heater 25 Spouting port 26 Plating liquid 27 Anode electrode 28 Cathode pin 29 Plating substrate

Claims (5)

[Claims] 1. A jet-type plating apparatus, comprising a heating unit for heating the whole or a part of the back surface of a substrate to be plated. 2. The plating apparatus according to claim 1, wherein the back surface of the substrate to be plated is heated to a higher temperature from the center of the substrate to be plated toward the outer peripheral portion. 3. A plating apparatus comprising a jet type plating apparatus, comprising a flow rate adjusting section for adjusting a flow rate of a plating liquid on a surface of a substrate to be plated. 4. The plating apparatus according to claim 3, wherein the shape of the flow rate adjusting portion is a thin plate shape having a large number of openings. 5. The plating apparatus according to claim 4, wherein the formation density of the openings increases toward the outside from the center of the plating solution spouting.