TRENCH ETCHING METHOD

摘要

PURPOSE: A method for etching a trench is provided to easily form a vertical deep trench without generating a black silicon by using Ar/Cl2 plasma etching used a hard masking layer as an etching stopper. CONSTITUTION: The method comprises the steps of forming a photoresist pattern(15) on a silicon substrate(11) having a hard masking layer(13); patterning the hard masking layer(13) using the photoresist pattern(15) as a mask; and forming a deep trench(17) by a plasma etching used the hard masking layer(13) as an etching stopper. The plasma etching is used Ar/Cl2 as a gas chemistry, and performed an ion-assisted etching using a physical effect of the Ar gas and a chemical effect of the Cl2 gas, thereby forming deep trench(17) without generating black silicon.