JPS61135141A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To enable the prevention of breakage of a final passivation film by baking the substrate in a vacuum once after spatter etching. CONSTITUTION:On a wafer substrate 1, a passivation PSG film 2, the first layer aluminum wiring layer 3, and a nitride film 4 are formed. On an interlaminar nitride film 4, the second layer aluminum wiring layer 5 is formed by photolithography and spatter etching. As a spattering gas sticks into the interlaminar nitride film 4 at spatter etching, the pressure inside the device is reduced to a vacuum subsequently after spatter etching and the temperature under the predetermined value is held for a few quarters of an hour and baking is done. A spattering gas is exhausted and a final passivation film 6 is formed followed by final heat treatment to obtain the desired semiconductor device. The partial swelling of the second layer aluminum wiring layer and accordingly the partial breakage of the final passivation film can be prevented and also simplification of a baking process can be contrived.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method of manufacturing a semiconductor device, and particularly to a method of manufacturing a semiconductor device having two-layer wiring.

[Conventional technology]

Figures 2(a) and 2(b) show a schematic configuration of the final manufacturing process for a semiconductor device having this type of two-layer wiring using a conventional method.
That is, in each of these figures, the symbol l is the wafer substrate, and 2 is the passivation PS on the wafer substrate l.
G@, 3 is the first aluminum wiring layer on the PSGl 12, 4 is a nitride film as an interlayer insulating film, 5 is an interlayer nitride film 4
The upper second aluminum wiring layer 6 is a final passivation film covering these layers.

[Problem that the invention seeks to solve]

However, in the semiconductor device with the above configuration, the second
In the step of forming layer aluminum wiring layer 3.

Sputter etching is performed, and during this etching, argon gas, which is a sputter gas, penetrates into the nitride film layer. Thereafter, the steps from the first stage onwards are carried out, and a final heat treatment is performed to obtain the structure shown in FIG. 2(a). The particles gather under the second aluminum wiring layer 3, which has a low density, and the pressure lifts the second aluminum wiring layer 3, thereby causing the final pad page to rise as shown in FIG. There was an inconvenience that partial destruction of IfI8 occurred, reducing the reliability of the device itself.

In view of the above-mentioned problems with the conventional method, it is an object of the method of the present invention to provide a method for manufacturing a semiconductor device that does not ultimately cause damage to the final padding film.

[Means for solving problems]

In the method of manufacturing a semiconductor device according to the present invention, baking is performed in a vacuum after sputter etching to remove the argon gas that penetrates the nitride film during sputter etching.

[For production]

Therefore, in the case of the method of this invention, the argon gas that penetrates the nitride film during sputter etching is removed by baking, and then the subsequent processes are performed. This makes it possible to prevent partial lifting of the wiring layer.

〔Example〕

An embodiment of the method for manufacturing a semiconductor device according to the present invention will be described in detail below with reference to FIGS. 1(a) and 1(b).

FIGS. 1(a) and 1(b) sequentially show the manufacturing process of a semiconductor device to which this embodiment method is applied.
Figures (a) and (b) In the example method, the above-mentioned Figure 2 (a)
), (b) The same reference numerals as in the conventional method indicate the same or corresponding parts.

In this example method, as well as in the conventional example method,
A puffivated PSG film 2 on a wafer substrate 1. First layer aluminum wiring layer 3. A nitride film 4 is formed on each,
Further, a second aluminum wiring layer 5 is formed on the living nitride film 4 by using a normal photolithography method and a sputter etching method.
(FIG. 1(a)), but even here, during sputter etching, argon gas, which is a sputter gas, penetrates into the living room nitride film 4.

Therefore, in this embodiment method, immediately after the sputter etching in the sputtering equipment described above, the inside of the equipment is immediately reduced to a vacuum of about IX 1G-5 tarr, and
Baking is performed by holding at a predetermined temperature for several tens of minutes, and argon gas, which is a sputtering gas, is extracted from the interlayer nitriding fi4.Final passivation 1118 is then formed, and then final heat treatment is performed to obtain the intended semiconductor device. ((b) in the same figure).

Therefore, in the case of this embodiment method, the argon gas that penetrated the nitride film during sputter etching is removed by baking, and then the subsequent processes are performed and the final heat treatment is performed. , it is possible to prevent partial lifting of the second layer aluminum wiring layer and, by extension, partial destruction of the final padding film. By performing baking under vacuum and reduced pressure, the baking process can also be simplified.

〔Effect of the invention〕

As described in detail above, according to the method of the present invention, when forming two-layer wiring, after sputter etching for forming the second layer aluminum wiring layer, baking is performed in a vacuum once, and the nitride film is removed during sputter etching. By extracting the argon gas stuck in the wafer, it is possible to prevent the partial lifting of the second aluminum wiring layer and the partial destruction of the final passivation film during the final heat treatment. This makes it possible to significantly improve the reliability of semiconductor devices.

[Brief explanation of the drawing]

1(1) and 1(b) are cross-sectional views showing an embodiment of the method for manufacturing a semiconductor device according to the present invention in the order of steps, and FIGS. 2(a) and 2(b) are sectional views showing the conventional example of the same. FIG. 3 is a cross-sectional view showing a method for manufacturing a semiconductor device in the order of steps;
'l... Wafer substrate, 3... First layer aluminum wiring layer, 4... Interlayer nitride film, 5... Second layer aluminum wiring layer, 8... Final passivation. film. Figure 1 (b) Figure 2 (b) Procedural amendment (spontaneous) 1. Indication of case Patent application No. 59-258650 2.
Title of the invention: Method for manufacturing a semiconductor device 3, Person making the amendment 5, Detailed description of the invention in the specification subject to the amendment 6, Contents of the amendment (1) [Book B, page 2, lines 10.18 and 19, “ "Wiring layer 3" is corrected to "Wiring layer 5". (2) rIXlo torrJ on page 5, line 1 of the same book as “1
Correct as X 10 torr J. that's all

Claims (1)

[Claims] A passivation PSG film, a first aluminum wiring layer, and a nitride film are formed on the wafer substrate, and a second aluminum wiring layer is formed on the interlayer nitride film using ordinary photolithography and sputter etching. 1. A method of manufacturing a semiconductor device, comprising the steps of forming a semiconductor device, baking it, forming a final passivation film, and subjecting it to final heat treatment.