Patent ID: 6756312
Filing Date: 2004-06-29
Classification: C09K,C23F,H01L

Abstract:
A method of fabricating a semiconductor device comprising treating a wafer in a chamber with hydrofluoric (HF) gas, a first part of the wafer having a first etching property relative to the HF gas and a second part of the wafer having a second etching property, different from the first etching property, relative to the HF gas, the method including:supplying the HF gas into the chamber only during a first time period, assuming that a time between introduction of the HF gas into the chamber and starting of etching of the first part of the wafer is a first starting time, and a time between introduction of the HF gas into the chamber and starting of etching of the second part of the wafer is a second starting time, longer than the first starting time, supplying the HF gas for a first time period, which is longer than the first starting time but shorter than the second starting time, wherein the first starting time and the second starting time correspond to respective time periods in which water is generated by reaction of the HF gas with the first part and the second part, respectively in amounts at which etching rates of the first part and the second part increase, and evacuating the etching gas from the chamber.