JPS62281356A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To prevent the yield of the etching residue of a protecting film on the surface of a protruding metallic electrode, by forming a hole in a region, where the protruding metallic electrode for the protecting film is formed, and forming the protruding metallic electrode in a metallic conductor film, which is exposed in the hole by a plating method. CONSTITUTION:An insulating film 4 is formed on the surface of a semiconductor substrate 1. A platinum film 5 is formed in a region, where a protruding gold electrode is to be formed, on the insulating film 4. Thereafter, a photoresist film is formed on the entire surface. The film is patterned by an ordinary way, and a photoresist mask 8 is formed. After the photoresist mask 8 is removed, e.g., a polyimide resin film 9 is applied and formed to a required thickness as a protecting film on the entire surface. The polyimide resin film 9, which is the protecting film, is formed at first, and thereafter the protruding gold electrode 3 is formed by a plating method. Therefore it is not required to perform the etching process of the polyimide resin film 9 after the protruding gold electrode 3 is formed. Even if the surface layer part of the protruding gold electrode is formed in a porous state, etching residue is not yielded on the surface layer part.

Description

[Detailed Description of the Invention] 3. Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a method of manufacturing a semiconductor device, and in particular a method of manufacturing a semiconductor device having metal protruding electrodes such as a tape carrier type semiconductor device. Regarding.

[Prior Art] Tape carrier type semiconductor devices are generally configured such that a metal protrusion electrode is formed on the surface of a semiconductor substrate, and the metal protrusion electrode is pressed against the conductive surface of the tape carrier for mounting. .

Conventionally, a method for manufacturing this type of semiconductor device, particularly a method for manufacturing metal protrusion electrodes, has been carried out by the following steps.

First, a metal conductive film is deposited on the entire surface of a semiconductor substrate on which the required elements are formed, a photoresist film is formed on this, and this is patterned to open a window at the location where the metal electrode is to be formed. Expose the conductive film. and,
Plating is performed using the metal conductive film as a current path, and thick metal plating is applied to the portion exposed within the photoresist window to form a metal protrusion electrode.

Then, unnecessary portions of the metal conductive film are removed by etching, a protective film is then applied to the entire surface, and then the protective film deposited on the metal protrusions is selectively etched away. The metal protrusion electrode is exposed.

[While the invention is trying to solve the problem]

The conventional manufacturing method for metal protrusion electrodes described above involves coating a protective film after forming the metal protrusion electrode, and then removing the protective film by etching to expose the surface of the metal protrusion electrode. Therefore, the retention on the surface of the metal protrusion electrode! The film will be etched.

However, since the metal protrusion electrode is grown in a porous manner by a plating method, etching residue of the protective film is likely to be generated on the surface layer of the metal protrusion electrode with an extremely high probability.

Therefore, when the metal protrusion electrode is pressed onto the conductive surface of the tape carrier, this residue will be present between the metal protrusion electrode and the conductive surface, degrading the adhesion between the two and causing mechanical and electrical connection failures. The problem arises that this occurs.

[Failure to solve the problem]

The method for manufacturing a semiconductor device of the present invention prevents the generation of etching residue of a protective film on the surface of a metal protrusion electrode, and improves the reliability of mechanical and electrical connection to a conductive surface during mounting. .

The method for manufacturing a semiconductor device of the present invention includes a step of forming a metal conductive film as a current path during thinning, a step of forming a protective film on the metal conductive film, and a step of forming metal protruding electrodes of the protective film. The method includes a step of forming an opening in a region, a step of forming a metal protrusion electrode by plating on the metal conductive film exposed in the opening, and a step of etching away unnecessary portions of the metal conductive film. It is something that

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a plan view of a semiconductor device equipped with metal protruding electrodes formed by the method of the present invention, and FIG.
Shown in a) to (g). Note that each figure in Figure 2 is the same as Figure 1.
FIG. 3 is a cross-sectional view taken along line AA in the figure.

That is, in this embodiment, as shown in FIG. 1, a plurality of element chips are formed on a semiconductor substrate (silicon wafer) l on which required elements are formed, and each element chip is subjected to dicing to cut and separate the element chips from each other. A metal protrusion electrode, here a gold protrusion electrode 3 made of gold (Au), is disposed close to the line 2 .

First, as shown in FIG. 2(a), an insulating film 4 is formed on the surface of a semiconductor substrate 1, and a platinum film 5 is formed on this insulating film 4 in a region where a gold protrusion is to be formed. A selective etching method, a lift-off method, or the like is used to form the platinum film 5. Note that in the region of the dicing line 2, the insulating film 4 is removed to expose the surface of the semiconductor substrate 1.

Next, as shown in FIG. 2B, aluminum 6 is deposited on the entire surface by vapor deposition or sputtering, and then only the surface of the aluminum filter 6 is oxidized by anodizing to form an aluminum oxide layer 7.

Thereafter, as shown in FIG. 2C, a photoresist film is formed on the entire surface and then buttered by a conventional method to form a photoresist mask 8, and this is used as a mask to cover the aluminum oxide layer 7 and the aluminum 6. selectively etched. As a result, the aluminum 6 and the aluminum oxide layer 7 remain only in the region of the dicing line 2 and the region connected from this to the platinum film 5.

Note that the planar pattern shapes of the aluminum 6 and the aluminum oxide layer 7 are as shown in FIG. As a result, the platinum films 5 formed independently on each element chip are electrically interconnected by the aluminum 6, and this constitutes a metal conductive film that serves as a current path during plating, which will be described later.

After removing the photoresist mask 8, a protective film, such as a polyimide resin film 9, is coated on the entire surface to a desired thickness, as shown in FIG. 3(d). And the same figure (
As shown in e), the polyimide resin film 9 is etched using a photoresist lO patterned by a conventional method as a mask, and the gold protrusion electrode forming area and the dicing line area are etched away to form windows 9a and 9b, respectively. As a result, the platinum film 5 is exposed in the window 9a of the gold protrusion electrode formation region, and the aluminum oxide layer 7 is exposed in the dicing line region 2. This planar state is as shown in FIG. 3 above.

Then, the semiconductor substrate 1 is immersed in a gold plating solution, and plating is performed by passing a current between it and the anode electrode plate of the plating device, using the metal conductive film made of aluminum 6 and platinum TIIJ, 5 as a current path. As a result, as shown in FIG. 9(f), a gold plating layer of a required thickness, that is, a gold protrusion electrode 3, is formed on the platinum film 5 within the window 9a.

Thereafter, using the photoresist 10 and the formed gold protrusion electrode 3 as a mask, the aluminum oxide layer 7 and aluminum 6 exposed in the dicing line region 2 within the window 9b are etched away, as shown in FIG. 3(g). As a result, each platinum film 5 and gold protrusion electrode 3 are electrically independent and insulated from each other.

Then, by removing the photoresist 10, the semiconductor device is completed. As mentioned above, FIG. 1 is a plan view of this completed state.

Therefore, according to this method, the polyimide resin film 9 as a protective film is first formed, and then the gold protrusion electrode 3 is formed.
Since it is formed by a plating method, there is no need to perform an etching process on the polyimide resin film 9 after forming the gold protrusion electrode 3. Therefore, even if the surface layer of the gold protrusion electric scraper 3 is formed in a porous shape, no etching residue is generated on the surface layer, and therefore, when the gold protrusion electric scraper 3 is pressed against the conductive surface of the tape carrier, the mechanical physical and electrical connections can be made with high reliability.

In addition, in this method, since the window 9a is first opened in the polyimide resin film 9 to limit the formation area of the gold protrusion electrode, it is possible to suppress the horizontal expansion of the gold plating layer due to isotropic growth of the gold plating. It is also possible to miniaturize the semiconductor device by reducing the planar dimension of the gold protrusion electrode 3.

It goes without saying that other metals may be used for the platinum film and aluminum film that serve as current paths during plating, and metals other than gold may be used for the protruding electrodes.

〔Effect of the invention〕

As explained above, in the present invention, after forming a metal conductive film as a current path during plating, a protective film is formed on this metal conductive film, and an opening is formed in the area where the metal protrusion electrode is to be formed. A metal protrusion electrode is formed on the top by plating method,
After that, a step of etching away unnecessary parts of the metal conductive film is included, so there is no need to etch the protective film after forming the metal protrusion electrode, and it is possible to prevent etching residue from forming on the surface layer of the metal protrusion electrode. The mechanical and electrical connection reliability of the metal protrusion electrode can be improved. In addition, since the metal protrusion electrodes are formed by plating after providing an opening in the protective film, it is possible to prevent the lateral dimension of the metal protrusion electrodes from expanding and to miniaturize the metal protrusion electrodes, allowing for highly integrated semiconductor devices. It is also possible to aim for

[Brief explanation of the drawing]

FIG. 1 is a plan view of a semiconductor device formed by the method of the present invention, and FIGS. The figure is a plan view in the middle of the manufacturing process. 1... Semiconductor substrate, 2... Dicing line area,
3... Metal (gold) protruding electrode, 4... Insulating film, 5...
・Platinum film (metal film), 6...aluminum, 7...
aluminum oxide layer, 8... photoresist mask,
9... Protective film (polyimide resin film), 9a, 9b...
・Window, 10...Photoresist. ,,,/--51゛Agent Patent Attorney Akira Suzuki Futo□1~,Liichi,- Figure 2 Figure 3

Claims (2)

[Claims] (1) A process of forming a metal conductive film as a current path during plating in an area including a metal protrusion electrode formation area on a semiconductor substrate, a process of forming a protective film on this metal conductive film, and a process of forming a protective film on this metal conductive film. A step of forming an opening in a region where a metal protrusion electrode is to be formed, a step of forming a metal protrusion electrode by a plating method on the metal conductive film exposed in the opening, and then removing an unnecessary portion of the metal conductive film. A method for manufacturing a semiconductor device, comprising a step of removing by etching. (2) The metal conductive film is composed of metal films formed independently corresponding to the metal protrusion electrode formation areas, and a metal film that electrically connects these metal films to each other. 2. The method of manufacturing a semiconductor device according to claim 1, wherein a part of the metal film that is electrically connected to the semiconductor device is etched away.