JPH03273626A - Etching apparatus for aluminum alloy film - Google Patents

Abstract

PURPOSE:To realize an excellent etching shape and the high stability in etching steps by providing a conveying chamber having a two-way conveying arm at the intermediate part between an etching chamber and a processing chamber for performing corrosion preventing treatment and polymer deposition processing, and forming a corrosion resisting film on the side wall of a wiring before additional etching. CONSTITUTION:A silicon oxide film 31, an aluminum alloy film 32 and a patterned photoresist mask 33 are sequentially formed on a silicon substrate 35. The silicon substrate 35 is conveyed into an etching chamber 21 with a conveying arm 27 from an evacuated chamber 20. The substrate is just etched with the mixed gas plasma of, e.g. BCl3, Cl2, CHCl3 and N2. The substrate is automatically conveyed into a processing chamber 1 through a conveying chamber 2 with a two-way conveying arm 3. For example, deposition processing of polymer 4 containing fluorine is performed with CHF3 plasma. Then, the substrate is conveyed into the etching chamber 21 again through the conveying chamber 2 with the two-way conveying arm 3. Additional etching is performed, and residue 34 is removed. The substrate is conveyed into the processing chamber 1 with the two-way conveying arm 3 again, and corrosion preventing treatment is performed.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an apparatus for etching aluminum alloy films in semiconductor devices.

BACKGROUND OF THE INVENTION In recent years, semiconductor devices using multilayer wiring formed of a plurality of aluminum alloy films or multilayer structure films including aluminum alloy films have been used.

A conventional aluminum alloy film etching apparatus will be described below.

FIG. 3 is a plan view of a conventional aluminum alloy film etching apparatus, where 20 is an inlet-side vacuum evacuation chamber, 21 is boron trichloride (BCe+), chlorine (Cf!x), trichlormethane<CHCe 3 ), an etching chamber using a mixed gas of nitrogen (N2), 22 a corrosion prevention treatment chamber using trifluoromethane (CHF3), and 23 a semiconductor substrate (hereinafter simply referred to as the substrate) having an aluminum alloy film. A transfer chamber for vacuum transfer from the etching chamber 21 to the corrosion prevention processing chamber 22, 24 an exit side atmosphere opening chamber, 25 a wafer cassette, 26 an exhaust port, 27 a transfer arm, 28 a chamber door, and 29 a lower electrode. FIG. 4 is a cross-sectional view of a substrate during the manufacturing process of an etching method using a conventional aluminum alloy film etching apparatus, in which 30 is a silicon semiconductor substrate, 31 is an oxide film formed on the semiconductor substrate A silicon film 32 is an aluminum alloy film containing trace amounts of silicon and steel formed on the silicon oxide film 31.
3 is a photoresist mask patterned on the aluminum alloy film 32, and 34 is an etching residue.

The operation of the aluminum alloy film etching apparatus constructed as described above will be explained below.

As shown in FIG. 4(a), a silicon oxide film 31. Aluminum alloy 1132 is placed on top of that, and photoresist mask 33 is patterned on top of that.
The substrate 35 subjected to this process is automatically transferred from the wafer cassette 25 shown in FIG. 3 to the inlet side evacuation chamber 20, and is evacuated to a vacuum. Next, the substrate 35 is automatically transported to the etching processing chamber 21 by the transport arm 27, and the BCI! 3, Cf! 2,
The aluminum alloy film 32 is etched by a mixed gas plasma of CHC (13, N2). In this case,
At the end of etching (just etching), an etching residue 34 is seen as shown in FIG. 4(b), so when additional etching is performed, the etching residue 34 is removed as shown in FIG. 4(c). The substrate 35 is the transfer arm 2
7, it is automatically transported to the corrosion prevention processing chamber 22 via the transport chamber 23, where it is subjected to corrosion prevention treatment using CHF3 plasma. Finally, the substrate 35 is automatically transported by the transport arm 27 to the exit side atmosphere opening chamber 24, and after being exposed to the atmosphere,
The wafer is stored in a wafer cassette 25.

Problems to be Solved by the Invention However, in the conventional etching apparatus as described above,
An additional etching step is required to remove the residue. In this process, the side walls of the wiring made of aluminum alloy are exposed to plasma containing chlorine, so that etching progresses in the lateral direction, causing the side walls of the wiring to become rough as shown at 36 in Figure 4(C), and the cross-sectional shape of the wiring to be There were problems in that the aluminum alloy wiring became reversely tapered and the aluminum alloy wiring corroded due to chlorine penetrating into the side wall surface.

The present invention solves the above-mentioned conventional problems, and realizes an excellent etching shape and high stability of the etching process when etching an aluminum alloy film or a multilayer structure film containing an aluminum alloy film. The purpose of this invention is to realize an etching apparatus for aluminum alloy films.

Means for Solving the Problems In order to achieve the above object, the aluminum alloy film etching apparatus of the present invention is provided with an etching chamber, a processing chamber for performing corrosion prevention treatment and polymer deposition treatment, and a two-way transfer arm in the middle thereof. The structure includes a transfer chamber with a

Function: With this configuration, a semiconductor substrate having an aluminum alloy that has been etched up to the time of just etching in a reaction chamber using a chlorine-based gas is transferred to a processing chamber using a fluorine-based gas, and is coated with a corrosion-resistant coating made of a polymer containing fluorine. After forming the film, the film can be transported to an etching chamber using chlorine-based gas for additional etching.

EXAMPLE Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 is a plan view of an aluminum alloy film etching apparatus in one embodiment of the present invention. In Figure 1, 1
2 is a treatment chamber where corrosion prevention treatment and polymer deposition treatment are performed;
is a transfer chamber in which a substrate can be vacuum-transferred in both directions from the etching chamber 21 to the processing chamber 1. 3 is a bidirectional transfer arm.

The rest is the same as the conventional example. FIG. 2 is a partial sectional view during the manufacturing process of a substrate when etching is performed using the etching apparatus according to the embodiment of the present invention shown in FIG.
4 in Figure (C) is a polymer containing fluorine. The rest is the same as the conventional example.

Next, the operation of the etching apparatus shown in FIG. 1 will be explained.

First, as shown in FIG. 2(a), a silicon oxide film 31 is placed on a semiconductor substrate 30, an aluminum alloy film 32 is placed on top of the silicon oxide film 31, and a photoresist mask 3 is patterned on top of the silicon oxide film 31.
The substrate 35 subjected to step 3 is automatically transferred from the Ueno\cassette 25 to the inlet side evacuation chamber 20 and evacuated to vacuum.

Next, the substrate 35 is transferred to the etching chamber 21 by the transfer arm 27.
BCez, Ce2. CHCe3. N
2 (D) The aluminum alloy film 32 is etched by the mixed gas plasma until it is just etched as shown in FIG. 2, the substrate is automatically transported to a processing chamber 1 where corrosion prevention treatment and polymer deposition treatment are performed, and a deposition treatment of a polymer 4 containing fluorine is performed using CHF3 plasma, resulting in the substrate as shown in Fig. 2 (C). The wire 35 is automatically transported to the etching chamber 21 through the transport chamber 2, which can be transported in both directions by the bidirectional transport arm 3, and additionally etched, and the residue 34 is removed, resulting in the wiring as shown in FIG. 2(d). Since the polymer 4 on the sidewall surface can withstand additional etching treatment, the wiring sidewall is not exposed to chlorine-containing plasma.As a result, the wiring sidewall surface may become rough, the cross-sectional shape may become reversely tapered, or the sidewall surface may become uneven. The problem of aluminum alloy wiring corroding due to adhesion of chlorine does not occur.Next, the substrate 35 is passed through the transfer chamber 2, which can be transferred in both directions by the bidirectional transfer arm 3, and subjected to corrosion prevention treatment and polymer deposition treatment. Room 1
The material is automatically transported to the factory and subjected to corrosion prevention treatment using CHF3 plasma. Finally, the substrate 35 is automatically transported by the transport arm 27 to the exit side atmosphere opening chamber 24, and after being exposed to the atmosphere, is stored in the wafer cassette 25.

As described above, according to this embodiment, the conventional transfer chamber 23 is made bidirectionally transferable, and the conventional corrosion prevention treatment chamber 22 is also used as a polymer accumulation treatment chamber, so that fluorine is removed before additional etching. Since a corrosion-resistant film made of a polymer containing aluminum alloy can be formed on the wiring sidewall, the wiring sidewall made of aluminum alloy is not exposed to etching containing chlorine, resulting in an excellent etched shape and a faster etching process. High stability can be achieved.

Effects of the Invention As described above, according to the aluminum alloy film etching apparatus of the present invention, a transfer chamber having a bidirectional transfer arm is provided between the etching chamber and the processing chamber for performing corrosion prevention treatment and polymer deposition treatment. , a corrosion-resistant film made of a polymer containing fluorine is formed on the wiring m wall before additional etching is performed on the aluminum alloy film, and since it is not exposed to additional etching containing chlorine, an excellent etched shape is achieved, and the etching High process stability can be achieved.

[Brief explanation of drawings]

FIG. 1 is a schematic plan view of an aluminum alloy film etching apparatus in one embodiment of the present invention, and FIGS. 2(a) to (d)
3 is a cross-sectional view of a main part of a substrate during the manufacturing process of an etching method using an etching apparatus for an aluminum alloy film according to an embodiment of the present invention, FIG. 3 is a schematic plan view of a conventional etching apparatus for an aluminum alloy film, and FIG. Figures (a) to (c) are cross-sectional views of essential parts of a substrate during the manufacturing process of an etching method using a conventional aluminum alloy film etching apparatus. 1... Processing room, 2... Transfer room, 3...
...Bidirectional transfer arm, 4...Polymer

Claims (2)

[Claims] (1) Etching the aluminum alloy film of a semiconductor device in which a silicon oxide film is formed on a silicon substrate, an aluminum alloy film is formed on the silicon oxide film, and a patterned photoresist film is formed on the aluminum alloy film. 1. An etching apparatus for an aluminum alloy film, characterized in that the apparatus comprises an etching chamber, a processing chamber for performing corrosion prevention treatment and polymer deposition treatment, and a transfer chamber having a bidirectional transfer arm located in between. (2) A claim for introducing chlorine gas or a mixture of chlorine-containing gas into the etching chamber, and introducing fluorine gas or a mixture of fluorine-containing gas into the processing chamber where corrosion prevention treatment and polymer deposition treatment are performed. Item 1. The aluminum alloy film etching apparatus according to item 1.