JPH04350940A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To provide a method of manufacturing a semiconductor device, which can use a desired metal for a barrier metal layer and offer high through-put. CONSTITUTION:A semiconductor substrate 1 is provided with bonding pads 3 covered with an insulating film 2. A conductive layer 4, for use in a later electrodeposition, is formed on the substrate, and an insulating film 5 is formed. A photoresist having holes above the bonding pads is applied, and it is used as an etching mask to remove the insulating film in the areas corresponding to the holes. Then, a barrier metal layer 27 is formed by a lift-off technique. When solder is applied by electrodeposition, the bonding pads are selectively plated since the other areas are covered with the insulating film. The solder plating 8 is used as a mask to selectively etch the insulating film 5 and the conductive layer 4. Finally, protruding electrodes are formed by a reflow of the solder 8. According to this method, a desired metal can be used for the barrier metal, and throughput is also improved.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for manufacturing semiconductor devices, and more particularly to a semiconductor device having protruding electrodes (bumps).

0002

[Prior Art] Figures 6 to 13 are illustrated in, for example, a published magazine (Sanyo Giho Vol. 20 No. 1 Feb. 1988).
FIGS. 108-115) are cross-sectional views illustrating the conventional method for manufacturing a semiconductor device having protruding electrodes in order of steps.

[0003] Here, the steps after the step of opening the panvation film will be described. On a substrate (not shown) having an Al pad 10 and an open panvation film (see FIG. 6), a barrier metal 12 is formed (FIG. 7), and then a plating mask pattern is formed using a photoresist 13. (
(Fig. 8), then Cu plating 14 (Fig. 9) and solder plating 15 (Fig. 10) for electrodes are performed, and the mask pattern is removed (
11) and barrier metal removal (FIG. 12). Finally, reflow is performed to heat and melt the solder to form a spherical part 16 (FIG. 13), and the solder bump process is completed. Note that the barrier metal layer and Cu plating layer that appear here are, of course, solder barrier layers. Such semiconductor device manufacturing methods have generally been mainstream.

0004

However, in such a method, the barrier layer may be a metal that can be selectively etched such as Cu or a metal that can be electrolytically plated. Difficult to etch
In addition, in the case of metals that cannot be easily electroplated, there is a problem in that they cannot be manufactured using the above-mentioned manufacturing method.

[0005]

Means for Solving the Problems The method for manufacturing a semiconductor substrate of the present invention includes (a) forming a conductive first layer on the semiconductor substrate when forming a protruding electrode on a bonding pad of the semiconductor substrate; (b) coating the semiconductor substrate with an appropriate photoresist or the like, and forming a resist pattern in which the bonding pad portion is opened using photolithography or the like; After etching the second layer using this resist pattern as a mask, a suitable metal or the like is deposited, and then the resist pattern is peeled off (lifted off) to form a third layer on the bonding pad. (c) electrolytically plating a suitable metal or the like on the substrate to form a plating layer on the third layer, and reflowing this plating layer to form a fourth layer. It is what it is.

[0006]

[Operation] By using this manufacturing method, it is possible to manufacture a semiconductor substrate as described above (with bumps) even if a metal that cannot be selectively etched is used for the barrier layer, and the photolithography process can also be performed in one step. This improves throughput.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be explained in detail below based on embodiments shown in the drawings. 1 to 5 are configuration cross-sectional views for explaining the present invention. First, as shown in FIG. 1, a bonding pad 3 covered with an insulating film 2 such as polyimide is used.
A conductive layer 4 to be used in a later electroplating process is coated with, for example, Ti by vacuum evaporation to a semiconductor substrate 1 having a thickness of 0.3 μm.
m thickness, and then an insulating film 5 such as a SiNX film is formed.
is formed to a thickness of 0.2 μm by P-CVD or the like.

Next, as shown in FIG.
After spin-coating a photoresist 6 on the bonding pad, a window is opened on the bonding pad using photolithography, and the insulating film 5 in the window-opened area is removed by etching using the photoresist 6 as a mask.
A three-layer metal layer 7 of u is deposited on the entire surface.

Next, as shown in FIG. 3, photoresist 6
is removed (lifted off) to form a barrier metal layer 27, and then solder is electrolytically plated. At this time, since the area other than the bonding pad is covered with the insulating film 5,
Only the bonding pads are selectively plated to obtain a plated layer 8.

Next, as shown in FIG. 4, using the solder plating layer 8 as a mask, the insulating film 5 is coated with HF, and then the conductive layer (
Ti) is sequentially etched with EDTA etc.

001
1] Finally, the solder plating layer 8 is reflowed to obtain a protruding electrode 28 as shown in FIG.

0012

[Effects of the Invention] According to the present invention, even if a metal that cannot be selectively etched or a metal that cannot be electrolytically plated is used as a barrier metal, a bump can be formed as in the embodiment shown in FIG. 1, and a manufacturing method thereof can be used. Since this is simple and easy, it is possible to provide a bump manufacturing method with high throughput.

[Brief explanation of the drawing]

FIG. 1 is a diagram for explaining the first step of a manufacturing process in an embodiment of the present invention.

FIG. 2 is a configuration explanatory diagram showing the second step of the manufacturing process in the above embodiment.

FIG. 3 is a configuration explanatory diagram showing the third step of the manufacturing process in the above embodiment.

FIG. 4 is a configuration explanatory diagram showing the fourth step of the manufacturing process in the above embodiment.

FIG. 5 is a configuration explanatory diagram showing the fifth step of the manufacturing process in the above embodiment.

FIG. 6 is a configuration explanatory diagram showing the first step of a manufacturing process in a conventional example.

FIG. 7 is a configuration explanatory diagram showing the second step of the manufacturing process in the conventional example.

FIG. 8 is a configuration explanatory diagram showing the third step of the manufacturing process in the conventional example.

FIG. 9 is a configuration explanatory diagram showing the fourth step of the manufacturing process in the conventional example.

FIG. 10 is a configuration explanatory diagram showing the fifth step of the manufacturing process in the conventional example.

FIG. 11 is a configuration explanatory diagram showing the sixth step of the manufacturing process in the conventional example.

FIG. 12 is a configuration explanatory diagram showing the seventh step of the manufacturing process in the conventional example.

FIG. 13 is a configuration explanatory diagram showing the eighth step of the manufacturing process in the conventional example.

[Explanation of symbols]

1 Semiconductor substrate 2 Polyimide as an insulating film 3 Bonding pad 4 Ti as a conductive layer 5 SiNX film as an insulating film, 6 Photoresist 7, 27 Barrier metal layer 8, 28 Solder plating layer 10 Al pad 11 Passivation film 12 Barrier metal 13 Photoresist layer 14 Cu plating layer 15 Solder

Claims (1)

[Claims] (a) When forming a protruding electrode on a bonding pad of a semiconductor substrate, a conductive first layer is deposited on the semiconductor substrate including the bonding pad, and then an insulating layer is formed on the semiconductor substrate including the bonding pad. Depositing a second layer (
b) Coat a suitable photoresist or the like on the semiconductor substrate, form a resist pattern with a window opened in the bonding pad portion by photolithography, etc., use this resist pattern as a mask to etch the second layer, and then etch a suitable photoresist. a step of depositing a metal etc. and then peeling off (lift-off) the resist pattern to form a third layer on the bonding pad; (c) electroplating a suitable metal etc. on the substrate; . A method of manufacturing a semiconductor device, comprising the steps of forming a plating layer on the third layer and reflowing the plating layer to form a protruding electrode.