SEMICONDUCTOR DEVICE AND METHOD OF MANUFACTURING THE SAME

摘要

PROBLEM TO BE SOLVED: To provide a very precise and reliable trench having a gentle tapered face near an opening. SOLUTION: A process of forming the trench in the surface of a semiconductor substrate comprises: a first etching process of selectively etching the surface of the semiconductor substrate exposed out of a mask using a mixed gas of hydrohalogen and fluorocarbon; a second etching process of etching the surface of the semiconductor substrate using a plasma of a mixed gas of a halogen- contained gas and oxygen or nitrogen after the first etching process; and a third etching process of etching the surface of the semiconductor substrate using a plasma of a mixed gas of a halogen-contained gas and oxygen after the second etching process.