JPH03129831A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To avoid the surface deterioration and wear of metallic protrusion electrodes by a method wherein the metallic protrusion electrodes are insulation- isolated while the upper surface thereof are being coat-covered with a polyimide resin layer. CONSTITUTION:First and second metallic films 2, 3 as the cathode side current channels are plated, metallic protrusion electrodes 5 comprising metallic plated films thinner than photoresist films 4 are formed on the opening parts of the second metallic films 3; and then a polyimide resin film 6 is formed to flatten the whole surface. Next, the upper layer part of the polyimide resin film 6 is etched away leaving the resin film 6 only on the metallic protrusion electrodes 5; the resist films 4 are peeled off; any unnecessary parts of the first and second metallic films 2, 3 are etched away; and finally the polyimide resin film 6 left on the metallic protrusion electrodes 5 is etched away. That is, the upper parts of the metallic protrusion electrodes 5 are protected by the polyimide resin film 6 when the electrodes 5 are insulation-isolated to be etched away. Through these procedures, the surface deterioration and wear of the metallic protrusion electrodes 6 by etching process can be avoided thereby enabling pressure fixing of the electrodes 5 on a tape carrier to be made highly reliable.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention is utilized in a method of manufacturing a semiconductor device for a tape carrier, and particularly relates to a method of manufacturing a semiconductor device that improves the method of manufacturing a metal protrusion electrode.

〔overview〕

The present invention provides a method for manufacturing a semiconductor device having a metal protrusion electrode made of a metal plating film, in which an upper layer portion of the metal film is removed by etching to electrically insulate and separate the metal protrusion electrode. By protecting the metal protruding electrode with polyimide resin, deterioration and wear of the surface of the metal protruding electrode due to etching can be prevented, and the reliability of pressure bonding to the tape carrier can be improved.

[Conventional technology]

Conventionally, in the manufacturing method of a semiconductor device for a carrier tape having a metal protruding electrode made of this kind of metal plating film, after the formation of the base wiring is completed, a first metal is added to strengthen the adhesion between the base wiring and the metal plating film. A second metal film is continuously deposited on the film and its upper layer as a barrier film to prevent the underlying wiring from reacting with the metal plating film to form a current path during plating. By performing plating using the resist film as a mask, a metal protrusion electrode made of a metal plating film is formed, and after peeling off the photoresist film, unnecessary parts of the first metal film and the second metal film are removed using the metal protrusion electrode as a mask. The metal film was removed by etching, and each metal protrusion electrode was insulated and separated.

[Problem that the invention seeks to solve]

In the conventional method for forming metal protruding electrodes made of metal plating films as described above, the first metal film and the second metal film are anisotropically separated in order to electrically insulate and separate each metal protrusion electrode after plating is completed. Since etching is removed by dry etching, the surface layer of the metal protrusion electrode is also etched, resulting in deterioration of the surface layer and thinning of the film, which has the drawback that it cannot be reliably pressed onto the conductive surface of the tape carrier.

An object of the present invention is to provide a semiconductor device which can form metal protruding electrodes without causing deterioration of the surface layer or thinning of the film by eliminating the above-mentioned drawbacks, and which can be reliably pressed onto the conductive surface of a tape carrier. The purpose is to provide a manufacturing method.

[Means for solving problems]

In the present invention, a first metal film for reinforcing adhesion and a second metal film for preventing reaction are laminated on a semiconductor substrate on which elements and underlying wiring are formed, and a photoresist film is further formed thereon. In a method for manufacturing a semiconductor device including a step of patterning and forming an opening at a predetermined position, plating is performed using the first and second metal films as current paths on the cathode side, and plating is performed on the opening of the second metal film. A process shop for forming a metal protruding electrode made of a metal plating film thinner than the thickness of the photoresist film, a process for forming a polyimide resin film so that the entire surface is flat, and a process for forming an upper layer of the polyimide resin film. A step of removing the polyimide resin film by etching and leaving the polyimide resin film only on the metal protrusion electrode, and peeling off the photoresist film and removing unnecessary portions of the first and second metal films by anisotropic dry etching. and a step of etching away the polyimide resin film left on the metal protrusion electrode.

[Effect]

In the present invention, the insulation separation of the metal protrusion electrode is performed while the upper surface of the metal protrusion electrode is covered and protected with a polyimide resin layer.

Therefore, deterioration and wear of the surface of the metal protrusion electrode due to etching can be prevented, and high reliability of pressure bonding to the tape carrier can be achieved.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1(a) to 1(e) are schematic cross-sectional views of the main manufacturing steps of a semiconductor device according to a first embodiment of the present invention, showing the case where a gold protrusion electrode is formed as the metal protrusion electrode.

First, as shown in FIG. 1(a), in order to strengthen the adhesion with the underlying wiring over the entire surface of the semiconductor substrate 1 (the elements are omitted in the illustration) after completing the elements and underlying wiring. A titanium film 2 with a film thickness of 0.5μ0 is deposited,
Furthermore, a platinum film 3 with a thickness of 0.1-0.1 mm is deposited on the upper layer to prevent reaction between the base and the gold protrusion electrodes. Since the titanium film 2 and the platinum film 3 are adhered to the entire surface of the substrate, they also serve as current paths between all the protruding electrodes during plating. Further, on the upper layer, a first photoresist film 4 with a thickness of about 25 μl is formed to serve as a mask material during plating, and an opening is opened in the area where the gold protrusion electrode is to be formed, and a platinum film is formed. Part 3 is exposed.

Thereafter, as shown in FIG. 1(C), the semiconductor substrate 1 is immersed in a gold plating solution, and a current is passed between the titanium film 2 and the platinum film 3 as current paths between the anode electrode plate on the plating apparatus side. By performing plating, a gold plating layer, that is, a fully protruding electrode 5 having a film thickness of about 20p is formed on the platinum film 3 exposed in the opening of the photoresist film 4. Here, all the protruding electrodes 5 are formed to be thinner than the photoresist film so that a low step of about 5 μm is formed in the opening.

After that, a polyimide resin film 6 of about 10μ is applied to the entire surface of the substrate.
The polyimide resin is applied to a thickness of m, and the concave portion of the opening is filled with polyimide resin, and the surface of the substrate is flattened.

Thereafter, as shown in FIG. 1C, the polyimide resin film 6 is etched uniformly within the substrate surface, leaving the polyimide resin film 6 only in the recesses of the openings, that is, directly above all the protruding electrodes 5.

Thereafter, as shown in FIG. 1(d), the photoresist film 4 is completely removed, and the platinum film 3 and titanium film 2 are continuously etched by anisotropic dry etching using argon gas to remove all the protrusions of each. The electrodes 5 are electrically insulated and separated. At this time, since the upper layer of all the protruding electrodes 5 is protected by the polyimide resin film 6, they are not etched and can maintain the state after plating is completed.

Thereafter, as shown in FIG. 1(e), the polyimide resin film 6 is removed by etching with a hydrazine-based chemical solution, thereby completing a desired semiconductor device.

Therefore, according to this method, since the upper layer of the all-protruding electrode 5 is protected by the polyimide resin film 6 during the insulation separation etching, the entire protruding electrode 5 is not deteriorated or thinned by etching. When 5 is crimped onto the conductive surface of the tape carrier, mechanical and electrical connections can be made with high reliability.

FIGS. 2(a) to 2(a) are schematic cross-sectional views of main steps of a semiconductor device according to a second embodiment of the present invention.

Here, FIGS. 2(a) to 2(C) are similar to the first embodiment described above, and after the device is completed, a film of 0.5 μm in thickness is applied to the surface of the semiconductor substrate 210 to strengthen adhesion. A titanium film 22 and a platinum film 23 with a film thickness of 0.1 μI for preventing reactions are formed, and plating is performed using a positive type first photoresist film 24 with a film thickness of 7- as a mask.
A first gold wiring 28 with a film thickness of 3JIJB is formed, and directly above it, a film with a film thickness of 4μ left by etching back is formed.
m first polyimide resin films 26 are formed.

Next, as shown in FIG. 2 (6), a positive second photoresist film 27 with a film thickness of approximately 20 mm, which will serve as a mask during plating to form all protruding electrodes, is applied to the first 70 mm photoresist film. It is formed directly above the membrane 24. Here, since the polyimide resin film 26 is dissolved in the developer of the positive resist,
When patterning the second photoresist film 27, all of the first polyimide resin 26 within the entire projecting electrode formation region is removed, and the first gold wiring 28 is exposed.

Thereafter, as shown in FIG. 2(e), the first gold wiring 28
Then, in the same manner as when forming the first polyimide resin film 26, a fully protruding electrode 25 with a film thickness of 15 μm is formed on the first gold wiring 28, and a film thickness of 5 μm with a film thickness of 5 μm is formed directly above it by an etch-back method. A second polyimide resin film 29 is formed.

Thereafter, as shown in FIG. 2(f), the first photoresist film 24 and the second photoresist film 27 are completely peeled off in the same manner as in the first embodiment, and then platinum is etched by anisotropic dry etching. The film 23 and the titanium film 22 are removed by etching at the same time.

After that, as shown in FIG.
8 and the first polyimide resin film 26 and all protruding electrodes 2
By simultaneously removing the second polyimide resin film 29 on 5 by wet etching, the desired semiconductor device is completed.

Here, other metals may be used for the titanium film 22 that strengthens adhesion and the platinum film 23 that prevents reaction.
Metals other than all can also be used for the all-protruding electrode.

〔Effect of the invention〕

As explained above, the present invention involves coating the upper layer of the metal protrusion electrodes with a polyimide resin film when removing unnecessary metal films for electrically insulating and separating each metal protrusion electrode. As a result, the surface portion is not altered in quality or the film is thinned due to etching (this has the effect that the metal protrusion electrode can be pressure-bonded to the conductive surface of the tape carrier with high reliability).

[Brief explanation of the drawing]

FIGS. 1(a) to 1(e) are schematic sectional views showing main manufacturing steps of a semiconductor device according to a first embodiment of the present invention. FIGS. 2(a) to 2(a) are schematic cross-sectional views of the main manufacturing steps of a semiconductor device according to the second embodiment of the present invention. 1.21: Semiconductor substrate, 2.22: Titanium film,
3.23...Platinum film, 4.24.27...Photoresist film, 5.25...All protruding electrodes, 6.26.29
...Polyimide resin film, 28-gold wiring.

Claims (1)

[Claims] 1. On a semiconductor substrate on which elements and underlying wiring are formed,
A method for manufacturing a semiconductor device including the step of laminating a first metal film for strengthening adhesion and a second metal film for preventing reaction, and further forming a photoresist film thereon and patterning it to form an opening at a predetermined position. In the manufacturing method, plating is performed using the first and second metal films as current paths on the cathode side, and a metal plating film having a thickness thinner than the thickness of the photoresist film is formed on the opening of the second metal film. a step of forming a metal protrusion electrode; a step of forming a polyimide resin film so that the entire surface is flat; and a step of etching away the upper layer of the polyimide resin film to leave the polyimide resin film only on the metal protrusion electrode. and removing the photoresist film and etching away unnecessary portions of the first and second metal films by anisotropic dry etching, and removing the polyimide resin film left on the metal protrusion electrodes. A method for manufacturing a semiconductor device, comprising the step of removing by etching.