Optimization Study on the Reactive Ion Etching for SiO_2

The reactive ion etching for SiO2 was performed using CHF3,CF4,CHF3+CF4,CHF3+O2,and CF4+O2 as etching gases respectively.After the optimal etching gas had been ascertained,the relationship between RF power the ratio of different gases and the three major parameters of etching rate,uniformity selectivity was researched.By comparative analysis of the etching results,the optimized etching process was obtained with the etching rate of 79nm/min,the uniformity of 4% and the PR selectivity of 0.81.