JPH0287526A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To increase throughput, and obtain a semiconductor device of high reliability by a method wherein, after a photoresist film, in which a reserved region for forming a protruding electrode is opened, is formed on a wiring, and a lamination film and a conductor film are formed in order, a part existing on the film is eliminated at the time of eliminating the photoresist, and the residual conductor film is fused. CONSTITUTION:A liquid type photoresist film 14 excellent in adhesion is stuck on the main surface of a semiconductor wafer 11, and further a dry-film type photoresist film 15 is stuck; a lamination film 17 composed of three layers of Cr, Cu and Au is m formed, and a conductor film 18 of Pb-Sn is formed thereon. After that, at the same time when a first and the second photoresist films 14, 15 are eliminated, parts of the lamination film 17 and the conductor film 18 existing on the photoresist films 14, 15 are eliminated, and the residual conductor film 18 is fused by wet back; thereby forming a ball type protruding electrode. As a result, the process for forming a protective film is not present, so that throughput can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to semiconductor technology, and more particularly, to a technology that is particularly effective when applied to semiconductor chip mounting technology.

[Prior Art] One of the technologies for bonding a semiconductor chip to a substrate such as a package is the CCB technology. In this CCB technology, protruding solder electrodes are formed on the AQ wiring of the semiconductor chip, and solder is bonded through the protruding electrodes. The semiconductor chip is directly fixed to a substrate such as a package. Regarding such technology, for example, "Nikkei Electronics" No. 265, published by Nikkei McGraw-Hill on September 24, 1984,
It is described on pages 294 to 294.

FIGS. 2A to 2D show an example of a method for forming the protruding electrodes. The method of forming it will be specifically explained as follows.

First, after the final wiring process is completed, a silicon nitride film is formed over the entire surface of the AQ wiring 3 by plasma CVD. Thereafter, using a photoresist film (not shown) deposited on the silicon nitride film as a mask, the silicon nitride film is selectively removed so that a part of the surface of the AQ wiring 3 is exposed. As a result, a first protection film 1 made of a silicon nitride film is formed. The state that has been completed up to this point is shown in FIG. 2(A).

Next, after removing the photoresist film serving as a mask, a silicon oxide film is deposited over the entire surface of the protection film 1 by sputtering. And again,
The silicon oxide film is selectively removed using a photoresist film (not shown) as a mask to form a second protection film 5 made of a silicon oxide film as shown in FIG. 2(B).

Next, the photoresist film serving as a mask is removed, and then a laminated film consisting of three layers of Cr, Cu, and Au is formed on the entire surface. Then, the base electrode 6 is formed by patterning the laminated film using a photoetching technique. The state that has been completed up to this point is shown in FIG. 2(C).

After that, a metallized layer for cooling is formed on the back surface of the semiconductor wafer. Next, a film and a dry film-like photoresist film are sequentially formed on the liquid photoresist 1, and the portions of the film corresponding to the regions where the protruding electrodes are to be formed are selectively removed and opened in both photoresists 1. A conductor film of Pb-8n is formed over the entire surface. Thereafter, the conductor film is selectively removed using a lift-off technique so that the conductor film remains only in the area corresponding to the area where the protruding electrodes are to be formed, and the remaining conductor film is melted by wet 1-bank (heat treatment) to form a ball. A protruding electrode 7 having a shape is formed. The state that has been completed up to this point is shown in FIG. 2(D).

[Problems to be Solved by the Invention] However, when a conductive film is formed by the method described above, the following problems arise.

That is, according to the above method, in forming the protruding electrode,
The first and second protection films 1.5 are formed, and the selective removal of the laminated film that will become the exposed base electrode 6 and the selective removal of the conductor in the protrusion chamber (i7) are performed in separate steps. As a result, it takes a long time to form the protruding electrode 7.

There has been a problem in that the throughput in the semiconductor device manufacturing line deteriorates.

In addition, in the above technique, after forming the base electrode 6, a photolithography process for etching it and a heat treatment process for forming a backside metallized layer are performed, so the base electrode 6 is oxidized and voids are generated in that part. , there was a problem that the solder wettability of the base electrode 6 deteriorated.

Furthermore, there is a risk that Cu constituting the base electrode 6 may be etched during etching for forming the base electrode 6.

Note that in the case where the protection films 1 and 5 are not used, there is a risk that the underlying AQ wiring 3 may be etched when the underlying electrode 6 is etched.

The present invention has been devised in view of these points, and its main object is to provide a method for manufacturing a semiconductor device that can improve throughput and form highly reliable protruding electrodes.

The above and other objects and novel features of the present invention will become apparent from the description of this specification and the accompanying drawings.

[Means for Solving the Problems] Representative inventions disclosed in this application will be summarized as follows.

That is, the method for manufacturing a semiconductor device according to the present invention is as follows.

A photoresist film with an opening in the area where the protruding electrodes are to be formed is formed directly on the wiring, and then a laminated film serving as a base layer and a conductive film serving as the protruding electrodes are sequentially formed. The protruding electrodes are formed by simultaneously removing the portions existing on the photoresist film and melting the remaining conductive film.

[Function] According to the above-mentioned means, since there is no step of forming a protection film, the number of man-hours for forming the protruding electrodes is reduced accordingly.6 As a result, the time for forming the protruding electrodes can be shortened, and furthermore, the process of forming the protruding electrodes can be shortened. Throughput on the device manufacturing line can be improved.

Furthermore, according to the above-mentioned means, when selectively removing the base electrode and the conductor film, both are selectively removed at the same time using a lift-off technique, compared to the conventional technology in which the selective removal of the base electrode and the conductive film is performed separately. The process is shortened, and the throughput in the semiconductor device manufacturing line is improved accordingly.

Furthermore, according to the above-mentioned means, since the base electrode and the conductor film are formed in a self-lined manner using a common mask,
No photolithography process or heat treatment process is required from the formation of the base electrode to the formation of the conductor film. Therefore, the occurrence of voids 1 to 1 due to oxidation of the underlying electrode can be prevented, and as a result, a highly reliable protruding electrode can be obtained.

[Example] Hereinafter, an example of the method for manufacturing a semiconductor device according to the present invention will be described based on the drawings.

FIGS. 1A to 1F show a method for manufacturing a semiconductor device according to an embodiment. The explanation is as follows in order.

FIG. 1A shows a semiconductor wafer that has undergone the final wiring process. Here, reference numeral 11 indicates a semiconductor wafer, and reference numeral 12 indicates AQ'? It represents the Il pole.

Once the final wiring process has been completed in this way, the wiring shown in Figure 1 (B
), a metallized layer 13 is formed on the back surface of the semiconductor wafer 11.

Next, a liquid photoresist 14 with good adhesion is applied to the main surface of the semiconductor wafer 11, and a photoresist film (second photoresist film) 15 in the form of a dry film is further applied. Thereafter, the portions of both photoresist films 14 and 1.5 corresponding to the areas where the protruding electrodes are to be formed are removed to form an opening 16 in the neck, exposing a part of the surface of the AΩ wiring 12, as shown in FIG. 1(C).
The state will be as follows.

Next, the entire surface including the inside of the opening 16 is coated with a laminated film to serve as a base electrode, that is, a Cr. Cu and Au 3
A laminated film 17 consisting of layers is formed.

The state that has been completed up to this point is shown in FIG. 1(D).

Furthermore, a Pb-Sn conductor film 18 is disposed on the laminated film 17.
(Fig. 1(E)).

Thereafter, as shown in FIG. 1(F), the first and second photoresist films 14 and 15 are removed using a photoresist stripping solution.
At the same time, when removing the laminated film 17 and the conductor 1]5
j18 first photoresist film 14.

15 is removed. Thereafter, the remaining conductor film 18 is melted by wet-back to form a ball-shaped protruding electrode (solder bump).

According to the method for manufacturing a semiconductor device described above, the following effects can be obtained.

That is, according to the above manufacturing method, since there is no step of forming a protection film, which was conventionally performed, the number of man-hours for forming the protruding electrodes is reduced accordingly.
The time required to form the protruding electrodes can be shortened, and the throughput in the semiconductor device manufacturing line can also be improved.

Further, according to the above manufacturing method, the laminated film 1 serving as the base electrode
7 and the conductor film 18 that will become the protruding electrode, lift-off technology is used to selectively remove both at the same time, which shortens the process compared to the conventional technology that selectively removes them separately. This effect improves the throughput in the production line for semiconductor devices cut into strips.

Furthermore, according to the above manufacturing method, the laminated film 1 serving as the base electrode
7 and the conductor film 18 which becomes the protruding electrode are formed in a self-aligned manner using a common mask, so that no photolithography process or heat treatment process is required between the formation of the laminated film 17 and the formation of the conductor film 17.

Therefore, the base electrode is not oxidized and the generation of voids is prevented, thereby preventing deterioration of solder wettability.
As a result, a highly reliable protruding 8-electrode can be obtained.

Further, according to the above embodiment, the laminated film 17 serving as the base electrode
When selectively removing the conductor film 18 that will become the protruding electrode, both are simultaneously selectively removed using a lift-off technique, so that the Cu constituting the base electrode is not etched during the formation of the base electrode. Furthermore, when forming the base electrode, the underlying AQx[i12 is not etched.

Note that the above manufacturing method is effective when the size of the AQ electrode 12 is larger than the lift-off masks 14 and 15.

Although the invention made by the present inventor has been specifically explained above based on Examples, it goes without saying that the present invention is not limited to the above Examples and can be modified in various ways without departing from the gist thereof. Nor.

For example, according to the above embodiment, as the base electrode, Cr, C
A laminated film consisting of three layers of u and Au is used, but T
It may be a 3M film of i, Ni and Au, a two-layer film of Cr and Cu, or the like.

In addition, when forming the protruding electrode, in the above embodiment, P
Although a b-8n conductor film is used, an In-Pb conductor film or the like may also be used.

[Effects of the Invention] The effects obtained by typical inventions disclosed in this application are briefly explained below.

That is, in the method of manufacturing a semiconductor device according to the present invention, a resist film having an opening in a region where a protruding electrode is to be formed is formed directly on the wiring, and then a laminated film that becomes a base electrode and a laminated film that becomes a protruding electrode are formed. After sequentially forming the conductor film, the portions of the laminated film and the conductor film that are present on the photoresist film are removed at the same time as the photoresist film is removed, and the remaining conductor film is melted. Since the protruding electrodes are simply formed using the method described above and there is no step of forming a protection film, the number of man-hours for forming the protruding electrodes is reduced accordingly. As a result, the time required to form protruding electrodes can be shortened.
Furthermore, the throughput in the semiconductor device manufacturing line can be improved.

In addition, when selectively removing the base electrode and the conductor film, lift-off technology is used to selectively remove both at the same time, which shortens the process compared to the conventional technology that selectively removes them separately. Accordingly, the throughput in the production line of the live conductor device is improved.

Further, according to the present invention, since the base electrode and the conductor film are formed in a self-aligned manner using a common mask, no photolithography process or heat treatment process is required between the formation of the base electrode and the formation of the conductor film.

Therefore, oxidation of the underlying electrode does not occur and the generation of voids can be prevented, resulting in a highly reliable protruding electrode.

[Brief explanation of the drawing]

FIGS. 1(A) to (F) are longitudinal cross-sectional views of a semiconductor substrate in each step of an embodiment of the method for manufacturing a semiconductor device according to the present invention, and FIGS. 2(A) to (D) are longitudinal sectional views of a conventional semiconductor device. FIG. 3 is a vertical cross-sectional view of the semiconductor substrate in each step of the manufacturing method. 11... Semiconductor wafer, 12... AQ wiring, 1
4.15...Photoresist film, 17...Laminated film, 18...Conductor film. Figure 1 (A) (g) Figure (E) /7 (F) Figure 2 (A) Figure (D)

Claims (1)

[Claims] 1. When forming a protruding electrode on the wiring of a semiconductor chip via a base electrode, a photoresist film in which a region where the protruding electrode is to be formed is opened is directly formed on the wiring, and then a base electrode is formed. After sequentially forming a laminated film that will become an electrode and a conductor film that will become a protruding electrode, the portions of the laminated film and conductor film that are present on the photoresist film are simultaneously removed when the photoresist film is removed, and the remaining portions are removed. A method of manufacturing a semiconductor device, characterized in that the protruding electrodes are formed by melting a conductor film. 2. The semiconductor device according to claim 1, wherein the photoresist film has a two-layer structure, of which the lower layer is a liquid photoresist film and the upper layer is a dry film-like photoresist film. Production method.