JPH0567596A - Post processing of dry etching - Google Patents

Abstract

PURPOSE:To provide a post processing of dry etching which is suitable for preventing corrosion of aluminium alloy film, etc., after the dry etching. CONSTITUTION:A post processing chamber 2 generates plasma between the electrodes provides opposed each other 5 when a high frequency of 13.56MHz is applied from a high frequency power supply 4 in order to process a substrate 6 provided at the lower side thereof. Moreover, an electrode 7 having a plurality of holes is provided to prevent breakdown of aluminium pattern by charge up. In such an apparatus, after Al-Si(1%)-Cu(1%)/TiN/TiN film is etched within a processing chamber 1, a gas including ammonium is first flown in the post processing chamber 2, followed by the discharge. Next, a gas including carbon and hydrogen is flowed, followed by the discharge, a polymer is deposited in the thickness of about 200Angstrom on an aluminium alloy. Under this condition, a substrate is taken out under the atmospheric condition. This substrate did not generate any corrosion for a week or longer period.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dry etching post-treatment method, and more particularly to a dry etching post-treatment method suitable for preventing corrosion of an aluminum alloy film or the like after dry etching.

[0002]

2. Description of the Related Art As a conventional post-treatment after etching an aluminum alloy film, as described in JP-A-02-80585, a plasma treatment containing oxygen is carried out in another vacuum chamber, and then carbon and hydrogen are added. Alternatively, plasma treatment was performed with a compound gas containing these.

In such a method, it is possible to effectively remove chlorine adhering to the surface of the aluminum alloy film because the resist can be ashed or the aluminum alloy film can be plasma-treated without exposing the substrate after etching to the atmosphere.
Further, by treating with a compound plasma containing carbon and hydrogen to form a polymer, the surface of the aluminum wiring is protected and corrosion is prevented.

[0004]

However, in the above conventional structure, in the aluminum etching, the reaction product of the etching gas and the aluminum alloy film often adheres to the side wall of the aluminum wiring pattern.
In fact, in many cases, this sidewall deposit enables anisotropic processing of the aluminum alloy film. The side wall deposits are mainly reaction products of the resist and plasma of the aluminum alloy, and contain a large amount of carbon and chlorine.
Therefore, most of the carbon can be removed by the oxygen plasma treatment, but the chlorine adhering to the side wall of the aluminum wiring is not sufficiently removed. This residual chlorine reacts with water in the atmosphere to form hydrochloric acid, which dissolves aluminum and causes so-called corrosion. Furthermore, even if a polymer is formed, a laminated film of compounds such as Ti, W, Mo, etc. is much more vulnerable to corrosion as compared with a conventional aluminum alloy single layer film. Corrosion occurs even at the level of.

The present invention solves the above problems, and an object of the present invention is to provide a dry etching post-treatment method capable of obtaining a sufficient anticorrosion effect even for a laminated film which is susceptible to corrosion.

[0006]

In order to achieve the above-mentioned object, the present invention performs a plasma treatment on a substrate to be etched which has been treated with a gas containing ammonia or a compound thereof, and then, carbon and hydrogen or a compound containing them. It is achieved by performing plasma treatment with a gas containing.

[0007]

According to the present invention, with the above-mentioned structure, the surface of the substrate is neutralized by the plasma treatment containing ammonia or its compound, and the plasma is treated with carbon and hydrogen or these compounds to form a polymer on the surface of the aluminum alloy film. To do. As a result, even if the substrate comes into contact with moisture in the atmosphere, the substrate is in a nearly neutral state and is covered with the polymer, so that corrosion can be sufficiently prevented until the next step.

[0008]

EXAMPLE A dry etching post-treatment method according to an example of the present invention will be described below with reference to FIG. In FIG. 1, 1 is an etching treatment chamber, 2 is a post-treatment chamber, and 3 is a gate valve for connecting the treatment chamber 1 and the post-treatment chamber 2. Aftertreatment room 2
Uses a high frequency power source 4 to generate plasma between the opposite electrodes 5 with a high frequency of 13.56 MHz to process the substrate 6 placed below. Further, an electrode 7 having a plurality of holes is provided. This is because when the substrate 6 is directly exposed to plasma and the polymer is grown, the aluminum pattern may be destroyed due to charge-up. In such a device, Al--Si (1
%)-Cu (1%) / TiN / Ti film is etched in the processing chamber 1, and then NH ₃ / He = 5/100 cc / min as a gas containing ammonia and further O _{2 in the} post-processing chamber _2.
= 100 cc / min, discharge under the conditions of pressure = 400 mTorr and high frequency power = 500 W. Next to this
The pressure is 400 mTorr and the gas is CHF ₃ / O ₂ = 90 /
Flowing at a flow rate of 10 cc / min and discharging at high frequency power = 500 W for 30 seconds, about 200 Å polymer is deposited on the aluminum alloy. When taken out into the atmosphere in this state, 1
No corrosion occurred for more than a week. In the conventional method, corrosion occurred in about 2 days.

[0009]

As is apparent from the above examples, according to the present invention, after dry etching is performed, plasma treatment is performed with a gas containing ammonia or a compound thereof, and thereafter, carbon and hydrogen or a compound containing these are applied. Since the plasma treatment is performed with the gas described above, it is possible to provide a dry etching post-treatment method that can obtain a higher anticorrosion effect, is effective for an aluminum alloy film, in particular, a material vulnerable to corrosion, and can improve the yield.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional front view of an apparatus for performing a post-etching treatment method according to an embodiment of the present invention.

[Explanation of symbols]

 1 Etching processing chamber 2 Post-processing chamber 3 Gate valve 4 High frequency power supply 5 Counter electrode 6 Substrate 7 Electrode having a plurality of holes

Claims (2)

[Claims] 1. A dry etching of an aluminum film or an aluminum alloy film or a multilayer film of those films and another metal film is performed in a vacuum processing chamber using halogen or a halogen compound gas, and then ammonia or its compound is removed. A dry etching post-treatment method, which comprises performing a plasma treatment with a gas containing carbon and then performing a plasma treatment with a gas of carbon and hydrogen or a compound containing these. 2. The gas plasma treatment is performed by placing a substrate to be treated at a position apart from the plasma generating portion and further providing an electrode having a plurality of holes between the plasma generating portion and the substrate to be treated. The dry etching post-treatment method according to claim 1, wherein