JPS5887276A - Treatment after dry etching - Google Patents

Abstract

PURPOSE:To effectively prevent the breaking of a formed pattern due to corrosion by dry etching an Al film in a container and by treating the etched film with plasma of a gaseous mixture of fluorocarbon with oxygen without taking out the film from the container. CONSTITUTION:An Al or Al alloy film is laid on a semiconductor wafer or the like, and a pattern for electrode wiring or the like is formed on the film. The wafer is put in a reaction chamber to dry etch the Al film with a gaseous halogen compound. The etched film is then treated with plasma by introducing a gaseous mixture of fluorocarbon such as tetrafluoromethane with oxygen without taking out the film from the container. By this after-treatment the breaking of the patterned Al due to corrosion is prevented when the Al is taken out into air.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a post-dry etching treatment method, and in particular provides a dry etching post-treatment method for preventing corrosion of aluminum or the like after dry etching.

Conventionally, pattern etching of aluminum films or aluminum alloy films formed on semiconductor devices has mainly been carried out by so-called chemical etching using a phosphoric acid-based etching solution, but in this method, the photoresist used for the etching mask and Due to the adhesion with aluminum and the isotropy of wet etching, it is difficult to form fine patterns on aluminum, films, etc. with a pattern width of 5 μm or less, so in recent years so-called dry etching such as plasma etching or ion etching has been used. Pattern formation by this method is the mainstream method. But carbon tetrachloride.

If an aluminum film or aluminum alloy film is pattern-etched by plasma etching using a halogen compound gas such as boron trichloride or silicon tetrachloride, and then taken out into the air, the remaining patterned aluminum will corrode. The phenomenon of wire breakage occurs. -This is generally a type of halogen compound used as an etching gas - which is deposited on the surface of the substrate, and this polymer absorbs moisture in the air and reacts to form a halogen compound that is active against aluminum. generate,
This is said to cause corrosion of aluminum.

The present invention aims to solve the above-mentioned conventional problems, and therefore, after performing dry etching on aluminum, etc., a pattern is formed by performing a mixed gas plasma treatment of fluorocarbon and oxygen without taking it out of the vacuum container. This eliminates the phenomenon of wire breakage due to corrosion.

Hereinafter, the dry etching post-treatment method of the present invention will be explained with reference to Examples.

Parallel child! Using a dry etching apparatus having an electrode-type reaction chamber, a semiconductor wafer 3 having a photoresist pattern 2 for electrode wiring on an aluminum membrane 1 having a thickness of 1 μm is placed in the reaction chamber as shown in FIG. The aluminum film 1 is etched as shown in FIG. 2 by adjusting the pressure of carbon tetrachloride gas to 0.06 Torr and applying high frequency power of 13.56 MHz to the parallel plate electrodes. Etching speed is 0 high frequency power, es W/
, J, the surface is approximately 0.18 μm/n.

Next, as an example, fluorocarbon CF4=s was added to the reaction chamber without taking out the semiconductor wafer to the outside.
A mixed gas of co/min and oxygen o2=30 ca/min was introduced, and while the pressure was adjusted to 1 Torr, 13°5 csMHzO high frequency power was applied to the parallel plate electrodes.

The application time is approximately 3 minutes, assuming that the high frequency gravity is 0.5 W/eJ. Even if the semiconductor wafer is taken out into the air during this process, the formed pattern of aluminum will not corrode and the wires will not break. According to experiments, the flow rate ratio of CF4 and 02 introduced is 10% to 4.
0% is optimal; if it is less than 10%, the desired effect cannot be obtained, and even if it exceeds 40%, it takes a long time to obtain the desired effect. This is undesirable because silicon is damaged by plasma ions or electrons.

In addition to pure aluminum films, the method of the present invention can also be applied to Aj! −
A similar effect can be obtained for full miniram alloys such as 8i, An-Cu, and An-91-Cu.

As explained above, the present invention involves performing dry etching of aluminum or an aluminum alloy pattern using a halogen compound gas in an active state in a container, and then applying a mixed gas plasma of fluorocarbon and oxygen without taking the etching out of the container. This is a dry etching post-treatment method that can effectively prevent corrosion of formed aluminum or aluminum alloy, and has high industrial value.

[Brief explanation of the drawing]

FIGS. 1 and 2 are cross-sectional views illustrating a post-dry etching treatment method according to an embodiment of the present invention. 1... Aluminum film, 2... Fist/photoresist pattern, 30... Semiconductor wafer 0 Name of agent Patent attorney Toshio Nakao and 1 other person Figure 1 Figure 2

Claims (1)

[Claims] (1) Dry etching of aluminum or aluminum alloy using a halogen compound gas in an active state in a container, and then taking it out from the container. - A mixed gas plasma of fluorocarbon and oxygen A post-dry etching treatment method characterized by performing a treatment. (The dry etching post-treatment method according to claim 1F, wherein the 21 fluorocarbon is tetrafluoromethane, and the mixing ratio with respect to oxygen is 10% to 40%.