JPS6453548A - Dry etching of aluminum-silicon-copper alloy - Google Patents

Abstract

PURPOSE:To keep a positive taper of an etched shape and, at the same time, to remove residual copper by a method wherein, during an etching operation using a chlorine-based reaction gas, a temperature of a wafer during a reaction is controlled in a specific range or a temperature of a stage inside a reaction chamber is controlled in a specific range. CONSTITUTION:A chlorine-based reaction gas containing a depot gas such as CHCl3 or the like and containing nitrogen gas is introduced into a reaction chamber 1 from a reaction gas inlet port 5; the inside of the reaction chamber 1 is kept at a definite pressure; a high-frequency voltage is impressed from a high-frequency power supply 7; a plasma is generated between both electrodes 2, 3; an Al-Si-Cu alloy film on a wafer specimen 4 mounted on the electrode 2 to which the high-frequency voltage is supplied is dry-etched. If, during a dry etching operation of the Al-Si-Cu alloy, a temperature of the wafer during a reaction is controlled from 80 deg.C to 180 deg.C or if a temperature of a stage is controlled from 55 deg.C to 80 deg.C, an etched shape can be kept to be a positive taper and at the same time, the dry etching operation without a recidual substance of copper can be executed.