Patent ID: 7189653
Filing Date: 2007-03-13
Classification: H01J,H01L

Abstract:
1. An etching method for etching a silicon-containing oxide according to a pattern shape of a mask by using a gaseous mixture of gas containing carbon and fluorine, oxygen gas and inert gas, wherein recesses are formed in the silicon-containing oxide by an etching carried out under a condition that a ratio of a total flow rate of the gas containing carbon and fluorine and the oxygen gas to a flow rate of the inert gas ((a flow rate of the gas containing carbon and fluorine+a flow rate of the oxygen gas)/a flow rate of the inert gas) is smaller than 0.015, the recesses having approximately planar bottom portions formed of the silicon-containing oxide and approximately vertical sidewall portions formed of the silicon-containing oxide, and angled portions formed by the sidewall portions and the bottom portions being substantially right angled, and a formation of narrow groove shaped microtrenches is suppressed at the bottom portion sides of the angled portions.