Effects of Gas Carriers on Dry Etching of Silicon Dioxide

Argon and helium are often used as gas carriers in dry etching of silicon dioxide.Effects of argon or/and helium on the etching rate,uniformity,and selectivity to different substrate materials are investigated.Experiments show that,when argon is used to obtain an optimized etching,the flux ratio of argon and reactive gases should be adjusted to approximately 1∶1.On the other hand,when helium is used,a 2∶1 ratio is preferable.Compared with helium, argon is believed to be a better gas carrier.