JPH05218037A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To obtain a gold wiring of high reliability by forming the wiring and a conductive film in a self-alignment when the film for enhancing adhesive properties is formed between the wiring and an insulating film. CONSTITUTION:After a gold wiring is formed by a plating method, a conductive film 7 for enhancing adhesive properties between gold and an insulating film and a polyamide film 8 are deposited without peeling a resist pattern, the entire surface is etched until the pattern is exposed. Then, the resist is removed, a power supply film 4 and a barrier film 3 are selectively removed, and further the film 8 and the film 7 adhering to the sidewall of a polyamide resin film are removed. Thus, the conductive film can be formed on the gold wiring in a self-alignment.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a semiconductor device, and more particularly to a method of forming a film for improving adhesion with an insulating film directly on a gold wiring.

[0002]

2. Description of the Related Art In recent years, semiconductor devices have been miniaturized and multilayered, and gold wiring has begun to be used from the viewpoint of wiring reliability.

A conventional method for manufacturing gold wiring will be described with reference to FIG. As shown in FIG. 3A, first, titanium tungsten 3 as a barrier film and gold 4 as a power supply film for plating are deposited on the entire surface on the silicon oxide film 2, and then a resist pattern 5 is formed by a photolithography technique using a positive resist. To form. Next, as shown in FIG. 3B, gold plating is performed using the resist pattern 5 as a mask to form a gold wiring 6 having a desired film thickness, and then the resist pattern 5 is entirely removed. Next, as shown in FIG. 3C, the power supply film 4 and the barrier film 3 are selectively etched using the gold wiring 6 as a mask.
Next, as shown in FIG. 3D, a conductive film 7 that enhances the adhesion between the gold wiring such as titanium or titanium tungsten and the insulating film is deposited on the entire surface, and then the photolithography technique is used again to deposit on the gold wiring 6. Only the conductive film 7 is selectively removed by etching so as to remain. Next, as shown in FIG.
After removing the resist pattern 11, the interlayer insulating film 10 is deposited.

[0004]

In the above-mentioned conventional semiconductor device, the adhesion between gold and the insulating film can be improved by the conductive film 7, but the patterning of the conductive film 7 and the patterning of the gold wiring 6 are performed by different photolithography. Since the lithography technique is used, there is a problem that a margin for alignment is required, and if misalignment occurs, a short circuit occurs between the wirings, and the power supply film 4 is removed by etching using the gold wiring 6 as a mask. At this time, since the gold wiring 6 is also thinned by about the same as the thickness of the power supply film 4, it is necessary to form the gold wiring thickly in advance during plating, but this thinning is not stable and the thickness of the gold wiring is not stable. There was also a problem that contributed to the variation.

[0005]

In the semiconductor device of the present invention, a step of depositing a barrier film as a first conductive film and a power supply film as a second conductive film, and patterning a resist pattern for forming a gold wiring. And a step of selectively forming a gold wiring thinner than the resist pattern using the resist pattern as a mask by a plating method, and a conductive film for enhancing adhesion between gold and an insulating film as a third conductive film over the entire surface. A step of depositing, a step of spin-coating a coating film on the entire surface, and a coating film on at least the resist pattern and a third step.
Etching until the conductive film is completely removed, a step of removing the resist pattern, a step of etching the first and second conductive films using the coating film on the gold pattern as a mask, and the coating. Using the film as a mask, the third
And a step of removing the coating film.

[0006]

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

FIGS. 1A to 1E are sectional views of a semiconductor device in the order of steps for explaining the first embodiment of the present invention.

As shown in FIG. 1A, a silicon oxide film 2 is deposited on a substrate 1 on which a semiconductor element is formed, and then,
Titanium tungsten (TiW) 3 as a barrier film and gold 4 as a power supply film are both deposited to 1000 angstroms, a resist pattern is formed by using photolithography technology, and gold plating is selectively performed to form a gold wiring of 0.5 μm thickness. 6 is formed. Next, as shown in FIG. 1B, 50% titanium 7 is formed on the entire surface as a film for improving the adhesion between the gold and the insulating film.
Deposited about 0 Å and further polyimide film 8
Is applied to about 0.5 μm. Next, etching is performed so that at least the titanium 7 and the polyimide resin film 8 on the resist pattern 5 are removed. Here, the polyimide resin film 8
Is an O ₂ atmosphere RIE (reactive ion etch)
Then, the titanium 7 may be etched by RIE in a CF ₄ atmosphere. The resist pattern 5 is removed as shown in FIG.

Next, as shown in FIG. 1D, gold 4 and titanium tungsten 3 are etched by ion milling using the polyimide resin film 8 and titanium 7 as a mask. Next, FIG.
As shown in (e), isotropic etching, for example, the titanium 7 on the side wall of the polyimide resin film 8 is etched with a dilute solution of hydrofluoric acid, the polyimide is completely removed with a hydrazine solution, and then the interlayer insulating film 10 is deposited. ..

2A to 2E are cross-sectional views of the semiconductor device in the order of steps for explaining the second embodiment of the present invention.

The difference from the first embodiment is that the film deposited over the entire surface after gold plating is titanium tungsten 12,
The titanium-tungsten 3 which is a barrier film and the titanium-tungsten 12 are simultaneously isotropically etched with a hydrogen peroxide solution (FIG. 2D). In this example,
Compared with the first embodiment, there is an advantage that the process is simplified.

Although the embodiments have been described above, the barrier film is not titanium tungsten but titanium nitride,
A film having a barrier property such as platinum may be used, but when titanium nitride or platinum is used, titanium may be added in order to enhance the adhesion with the insulating film below. Instead of gold, a film of platinum or the like that is also a barrier film may be used as the power supply film. Furthermore, titanium is used as a film to enhance the adhesion between gold and the insulating film.
Although titanium-tungsten is used, a film that enhances the adhesiveness such as titanium nitride or chromium may be used. Further, although polyimide is used as the coating film, a silica film, a resist or the like may be used.

[0013]

As described above, according to the present invention, the gold wiring formation and the conductive film formation for enhancing the adhesion between the gold wiring and the insulating film can be made by self-alignment, and the power feeding film and the barrier film can be formed. Since the coating film is used as a mask on the conductive film that enhances the adhesiveness between the gold and the insulating film during the selective etching of, it is possible to realize the gold wiring that has good adhesiveness to the insulating film and good alignment accuracy. In addition, the controllability of the film thickness of the gold wiring is good.

[Brief description of drawings]

FIG. 1 is a sectional view showing a first embodiment of the present invention in the order of steps.

FIG. 2 is a cross-sectional view showing a second embodiment of the present invention in the order of steps.

FIG. 3 is a sectional view showing a conventional example in the order of steps.

[Explanation of symbols]

 1 substrate 2 silicon oxide film 3 titanium tungsten, barrier film 4 gold, power supply film 5 resist pattern 6 gold wiring 7 titanium, conductive film 8 polyimide resin film 10 interlayer insulating film 11 resist pattern 12 titanium tungsten

Claims (1)

[Claims] 1. A step of depositing a first conductive film and a second conductive film on a main surface of a semiconductor device, and a step of patterning a resist pattern for forming a gold wiring by using a photolithography technique. A step of forming a gold pattern by selectively and using the resist pattern as a mask and plating so as to be thinner than the resist pattern; and depositing a third conductive film on the entire surface without peeling the resist pattern. A step of spin-coating a coating film on the entire surface, etching at least until the coating film and the third conductive film on the resist pattern are all removed, and a step of removing the resist pattern, Etching the first and second conductive films using the coating film on the gold pattern as a mask; and the third conductive film using the coating film as a mask. A method of manufacturing a semiconductor device, comprising the steps of: isotropically etching; and a step of removing the coating film.