Method for preparing semiconductor including formation of contact hole using difluoromethane gas

摘要

A method for forming a contact hole in a semiconductor device includes the steps of forming a polymer layer on an upper portion and a side wall of photo resist mask, while etching an oxide layer under the photoresist mask to form a contact hole that uses an etchant gas comprising CH2F2 gas; and etching the oxide layer while stopping the supply of CH2F2 gas to the etching process.