JPS6046825B2 - Manufacturing method of semiconductor device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a semiconductor device, and more particularly to a method for manufacturing a multilayer wiring type semiconductor device that introduces a surface cleaning method for an upper wiring facility surface in a multilayer wiring structure.

Normally, when performing multilayer metal film interconnection through an interlayer insulating film, disconnection occurs in the upper layer interconnection in the conduction area between the upper layer and the lower layer, that is, in the through hole section, if the depth of the through hole section is deep. .

Conventionally, as a measure to improve the above, a liquid polyxane solution is applied onto the semiconductor substrate to form a film, and the interlayer insulating film in the through-hole portion is etched at an angle by utilizing the property of the film to corrode quickly. to reduce the step difference in the through-hole part,
Prevents disconnection of upper layer wiring. However, according to these methods, when the photoresist film used to open the through-hole portion adheres to the polysiloxane film, the photoresist film (or the hexafluoride used to improve the adhesion of the photoresist film) The organic substances in the methylene/diacine film) react to make the surface layer heterogeneous, and the surface treatment before attaching the metal film for wiring is incomplete, causing the adhesion of the metal film to deteriorate, resulting in micro wiring circuits. Peeling and disconnection of the wire and defective peeling of the bonding part occurred. An object of the present invention is to eliminate the above-mentioned drawbacks and improve the adhesion of the upper metal film by cleaning the surface using a polysiloxane film. The features of the present invention include the steps of depositing a polysiloxane film on the surface of the interlayer insulating film on the lower wiring, providing a photoresist film mask on a predetermined area, and opening a through hole in the interlayer insulating film; a step of removing the altered layer of the polysiloxane film remaining on the surface of the polysiloxane film after removing the photoresist film by irradiating it with a charged particle atmosphere; and a step of removing the entire amount of the polysiloxane film by chemical corrosion; This method of manufacturing a semiconductor device includes a step of providing an upper layer wiring in contact with a through-hole portion.

According to the present invention, the polysiloxane film used for the inclined corrosion of the interlayer insulating film in the through-hole portion comes into contact with the photoresist film and undergoes surface deterioration. By removing the polysiloxane film, the wettability of the chemical corrosive solution is improved, the corrosion rate is stabilized, and uniform removal of the polysiloxane film can be achieved, which improves the adhesion when installing the upper layer wiring, and improves the wettability of the chemical corrosion solution. This will eliminate defects in peeling and bonding defects.

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

For convenience of explanation, a case of a two-layer wiring structure of A1 film is shown using one through-hole region constituting the semiconductor device. 1 to 7 are cross-sectional views showing a method of manufacturing a multilayer wiring type semiconductor device according to an embodiment of the present invention.
N4 film) and an impurity diffusion element region 3, an A1 film 4 as a first layer wiring and a porous Al. An O3 membrane 5 is provided, and a thin non-porous Al. A first through-hole portion 7 is opened in the O3 film 6, and a vapor-phase grown SlO3 film 8, for example, is provided as an interlayer insulating film.

The interlayer insulating film can be used depending on the material of the Si3N4 film or polyamide film, and the deposition method such as sputtering (Figure 1).
. Next, a polysiloxane film 9 is provided on the main surface. The polysiloxane film is made into a film by applying a liquid, and the film is made from 150~
It is formed by baking at a temperature of 200°C (Figure 2). Subsequently, a pattern of the photoresist film 10 is provided in accordance with the pattern of the first through-hole portion 7 (FIG. 3).
Furthermore, using the photoresist film 10 as a mask, the polysiloxane film 9 in the opening of the photoresist film and the SlO2 film 8 as an interlayer insulating film are etched away with, for example, an ammonium hydrofluoride fluoride mixture, and the four surfaces of the underlying A1 film are removed. Expose and pass through the second
Finish the hole opening process. At this time, the opening end of the SiO2 film 8 forms a sloped part 11 because the upper polysiloxane film corrodes at a high rate (FIG. 4). Next, when the photoresist film 10 is removed, a degraded layer 12 caused by contact with the photoresist film remains on the surface of the polysiloxane film 9 (FIG. 5). In this state, oxygen or nitrogen plasma treatment is performed. For example, 1 to 0.1t0rr. Then, 02 gas is put into a plasma generation container and 02 plasma (charged particle state) is generated with 200 W and RF power, and the semiconductor device substrate is irradiated for a certain period of time to remove the above-mentioned altered layer (FIG. 6). After that, e.g. For example, the polysiloxane film 9 is uniformly removed using a hydrofluoric acid treatment solution, the surface is cleaned, and another A1 film 13 is provided as an upper layer wiring, thereby forming a two-layer wiring type semiconductor device of A1 film 4-A1 film 13. (Figure 7). According to the above embodiment, through-
The surface layer whose composition has changed due to the contact of the polysiloxane film used for tilting and corroding the hole with the photoresist film can be removed by plasma treatment, so the chemical etchant used when installing the upper layer wiring can be removed from the polysiloxane film. Because it wets well and exhibits a uniform corrosion rate, the lower layer AI film 4 in the through-hole area is not excessively corroded, the wiring adhesion of the upper layer AI film is maintained, and defective Al film peeling during bonding is prevented. This also prevents disconnection defects at the through-hole portion.

Figure 8 shows a photoresist film attached to the surface after a polysiloxane film was deposited and heat treated at each temperature for 0.5 hours, after which the photoresist film was removed and a corrosion treatment was performed using a hydrofluoric acid treatment solution. This shows the removal time of the time. A is a sample obtained without oxygen plasma treatment under the above conditions, and shows a long corrosion time and non-uniform results. on the other hand,
B was subjected to oxygen plasma treatment, and showed a short corrosion time and uniform results. In other words, B indicates that the surface of the polysiloxane film in contact with the photoresist film has been stabilized by oxygen plasma treatment, and therefore the hydrofluoric acid treatment when wiring the upper layer of the Al film can be completed in a short time. This makes it possible to prevent excessive corrosion of the through-hole portion as described above.

[Brief explanation of the drawing]

1 to 7 are cross-sectional views showing the manufacturing method of a multilayer wiring type semiconductor device according to an embodiment of the present invention in the order of steps, and FIG. 8 shows the relationship between the heating temperature and corrosion rate of the polysiloxane film. FIG. In addition, in the figure, 1... silicon substrate, 2...
SjO2 film, 3... impurity diffusion element region, 4...
...First layer AI film, 5...Porous Al2O
3 membrane, 6... non-porous Al2O3 membrane, 7...
...Through hole part, 8...Interlayer SiO2 film,
9...Polysiloxane film, 10...Photoresist film, 11...Through hole part SiO
2 Slanted part at the end of the membrane, 12... Altered layer of the polysiloxane film, 13... Second layer A1 film, A line... Corrosion state of the polysiloxane film having a surface altered layer, B line...
...This is the corrosion state of the polysiloxane film after plasma treatment.

Claims (1)

[Claims] 1. A step of depositing a polysiloxane film on the surface of the interlayer insulating film on the lower wiring, providing a photoresist film mask on a predetermined area, and opening a through-hole portion in the interlayer insulating film;
A method for manufacturing a semiconductor device, comprising the steps of: after removing the photoresist film, irradiating the surface of the polysiloxane film with charged particles; and chemically removing the polysiloxane film.