JPH03262148A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To prevent the deterioration of a polyimide film by a method wherein before an Al film which is an upper wiring layer is applied by sputtering, a metal protective film, such as a thin Al film or the like, is applied on the surface of a high molecular resin film, such as the polyimide film or the like. CONSTITUTION:A lower Al wiring layer 8 is formed on a field SiO2 film 7 on a semiconductor substrate and thereafter, a first polyimide film 9 is applied. Then, after an Al film 10 is applied on the film 9, the films 10 and 9 are etched and a through hole 11 is opened. An Al oxide film formed thin naturally on the layer 8 by sputter etching is removed by Ar ion dry etching using an RF etching method. Then, an Al film is deposited by sputtering, is patterned and an upper Al wiring layer 12 is formed. After that, a second polyimide film 13 is applied on the whole surface. Thereby, the deterioration of the film 13, which is used as a layer insulating film, is prevented, the generation of dust from an adhesion-preventing plate is also eliminated and the reliability of a multilayer interconnection can be improved.

Description

[Detailed description of the invention] 〔overview〕 The present invention relates to an interlayer structure of multilayer wiring of a semiconductor device.

A process of coating a polymer resin film on the surface of a lower aluminum wiring layer on a semiconductor substrate with the aim of realizing a wiring layer without altering the polyimide film in the multilayer wiring layer; ), a step of opening a through hole for electrode wiring connection through the metal film and the polymer resin film, and dry etching the inside of the through hole to remove the aluminum wiring layer. The structure includes a step of removing a surface oxide film of the substrate, and a step of covering the substrate with an aluminum film and patterning it to form an upper wiring layer (6).

[Industrial application field]

The present invention relates to an interlayer structure of multilayer wiring of a semiconductor device.

In recent years, polymer resin films such as polyimide films and glass films such as spin-on-glass (SOG) films have been used as interlayer insulating films for multilayer wiring in LSIs, instead of conventional phosphosilicate glass (PSG) films. , it has come to be widely used due to its cost, ease of flattening, and simplification of the process.

[Conventional technology]

FIG. 4 is an explanatory diagram of a conventional example.

In the figure, 19 is a field oxide film, 20 is an AN film,
21 is a polyimide film, 22 is a natural oxide film, 23 is a reaction chamber, 24 is a sputtering electrode, 25 is a wafer, 26
2 is an adhesion prevention plate, and 27 is a polyimide film.

A liimide film 21 is coated on the Aj2 film 2 film of the electrode wiring formed on the doped oxide film 19, and a through hole for connecting the upper layer wiring is opened on the lower layer AN film by etching.

Next, the Affi film on the upper layer of the multilayer wiring is coated by sputtering, but as a pretreatment, dry etching such as sputter etching or ion milling is performed to cover the Affi film with argon (
Ar) Opened by ions! As shown by the thin aluminum oxide film 22 naturally formed on the film 20, the etched polyimide film 21 adheres to the surface of the adhesion prevention plate 26 in the reaction chamber 23, but since it is made of stainless steel, the adhesion is poor. , the polyimide film 21 is peeled off and the wafer 25
If it adheres to the surface of the adhesion prevention plate 26, it may cause defects. The film is coated to improve adhesion.

[Problem to be solved by the invention]

As mentioned above, the Ar ions cause the inside of the through-hole! This hits not only the film surface but also the surface of the polyimide film, which is the five-layer insulating film.

Therefore, the resin structure of the polyimide film is changed, and the moisture resistance and insulation properties of the polyimide film itself are deteriorated.

In addition, the polyimide film hit by the Ar ions adheres to the surface of the anti-adhesion plate inside the device, and as the polyimide films are stacked, they peel off from between the polyimide films and scatter, creating dust. It causes

In view of one or more points, the present invention is provided for the purpose of realizing multilayer wiring without deteriorating the polyimide film and preventing the generation of dust within the device.

4, and the step of coating the metal film 4 and the polymer resin film 3.
a step of opening a through hole 5 for electrode wiring connection through the through hole, and dry etching the inside of the through hole 5,
This is accomplished by including the steps of removing the surface oxide film of the aluminum wiring layer 2, and covering the substrate with an aluminum film and patterning it to form the upper wiring layer 6.

[Means to solve the problem]

FIG. 1 is a diagram explaining the principle of the present invention.

In the figure, 1 is the field oxide film, 2 is the lower layer AI! ,
The wiring layers include a polymer resin film 3, a metal film 4, a through pole 5, and a β wiring layer 6 to the upper layer.

As a solution, go to the upper wiring layer! Before coating the film by sputtering, the surface of the polymer resin film such as polyimide is coated with a thin metal protective film such as a ΔN film.

That is, one object of the present invention is to cover the surface of a lower aluminum wiring layer 2 on a semiconductor substrate with a polymer resin film 3;
Metal film on the surface of the polymer resin film 3 [Function] In the present invention, the inside of the through-hole! Since only the metal protective film for protecting the film and polyimide is bombarded with pre-treated Ar ions, deterioration of the polyimide film is prevented, and peeling of the polyimide film attached to the anti-adhesion plate is also prevented, reducing the generation of dust. It can be suppressed.

〔Example〕

FIG. 2 is a schematic sectional view of an embodiment of the present invention in the order of steps. FIG. 3 is an anti-adhesion plate of an embodiment of the present invention.

In the figure, 7 is a 5i02 film, and 8 is a lower 7/2 wiring layer.

9 is the first polyimide film, lO is AI! , membrane, 11 is a through hole, 12 is an upper layer ^ρ wiring layer, 13 is a second polyimide film, and 14 is a stainless steel adhesion prevention plate coated with aluminum.

15 is polyimide film, 16 is to! membrane, 17 is a polyimide membrane, 18 is l! It is a membrane.

One embodiment will be explained with reference to FIG.

As shown in Fig. 2(a), the field S of the semiconductor planting board
To the lower layer on the iO□ film 7! Wiring layer 8 is formed to have a thickness of 1 μm.

As shown in Figure 2(b), the first polyimide film was
Coat to a thickness of m.

As shown in FIG. 2C, the first polyimide film 9 is coated with an An film 10 to a thickness of 500 mm.

As shown in FIG. 2(d), the helium film 10 and the botaimide film 9 are etched to open a through hole 11.

By sputter etching, a thin layer was created naturally on the lower layer wiring. The oxide film of 4 is etched by RF etching.
Remove by dry etching with Ar ions at 00 to 500 V for 60 to 90 seconds. At this time, since the surface of the polyimide film 9 is covered with the Affi film, even if the /1ffi film is scraped to some extent, it will not be damaged.

Incidentally, the spuck etching described above may be replaced with reactive sputter etching.

As shown in Figure 2(e), to! A film was sputter-deposited to a thickness of 1 μm and patterned to form the upper layer Ap.

A wiring layer 12 is formed.

As shown in FIG. 2(f), the entire surface is coated with a second polyimide film 13 to a thickness of 2 μm.

At this time, as shown in FIG. Since polyimide films and Hel films are alternately superimposed on the coating stainless steel adhesion prevention plate 14, these films will not peel off and will not adhere as dust on the semiconductor substrate.

〔Effect of the invention〕

As explained above, according to the present invention, deterioration of the polyimide film used as an interlayer insulating film is prevented, no dust is generated from the adhesion prevention plate, and the reliability of multilayer wiring technology is improved. However, it is large.

[Brief explanation of drawings]

FIG. 1 is a diagram explaining the principle of the present invention. FIG. 2 is a schematic cross-sectional view of the steps of an embodiment of the present invention; FIG. 3 is an adhesion prevention plate of an embodiment of the present invention; FIG. 4 is an explanatory diagram of a conventional example. In fig. 1 is a field oxide film. 2 is a lower AI wiring layer, and 3 is a polymer resin film. 4 is a metal film, 5 is a through pole 6 is to the upper layer
Wiring layer 7 is 5iOz film 8 is on the lower layer! A wiring layer 9 is a first polyimide film. 10 ha! 11 is a through hole 12 is an upper Aff wiring layer, 13 is a second polyimide film 1
4 is a SUS-made protective board plate 5 is a polyimide film 16 is a thin film, 17 is a polyimide film 18 is a 8! Membrane -〇■

Claims (1)

[Claims] A step of coating a surface of a lower aluminum wiring layer (2) on a semiconductor substrate with a polymer resin film (3), and a step of coating a metal film (4) on the surface of the polymer resin film (3). a step of coating, a step of opening a through hole (5) for electrode wiring connection through the metal film (4) and the polymer resin film (3);
Dry etching the inside of the through hole (5) to remove the surface oxide film of the aluminum wiring layer (2); coating the substrate with an aluminum film and patterning it to form an upper wiring layer (6); 1. A method of manufacturing a semiconductor device, the method comprising: forming a semiconductor device.