A NOVEL 2-STEP ETCHING TO SUPPRESS THE CHARGING DAMAGES DURING METAL ETCHING EMPLOYING HELICON WAVE PLASMA

A two-step etching has been performed to eliminate the plasma charging damages during helicon-wave plasma metal etching without selectivity loss, This technique utilized a normal etching recipe to remove the Al film and followed by an optimized etching recipe for the overetching step. By increasing the bias power and decreasing the source power, th e optimum etching recipe can cause the plasma more directionally and r educe the Al charging damages. Eventually, the damage mechanism was al so reported.