To obtain a dry etching treatment method in which a high selectivity ratio is compatatible with a fine working operation by a method wherein the temperature of a sample is changed between an etching treatment and an etching treatment at a step succeeding it and the etching treatments at different temperatures are executed.
A W polycide layer which is composed of a polysilicon layer 32 and a WSix layer 33 is formed on an SiO2 film 31 on a silicon substrate 30. In addition, the W polycide layer at a sample W in which a photoresist pattern 34 is formed on it is etched and treated, and the layer is worked to a pattern shape corresponding to the resist pattern 34. At this time, a main etching operation at room temperature is performed as a first step, and an etching operation at a low temperature is performed as a second step succeeding it. Thereby, even when a sidewall protective film which is formed is thin, it is possible to restrain a radical reaction due to a low temperature.
SHIROSAKI TOMOHIDE
HIRANO SHINSUKE
Next Patent: METHOD AND DEVICE FOR ETCHING OF AL WIRING