Study on the Reactive Ion Etching of Si_3N_4

Reactive ion etching(RIE)of silicon nitride was performed with CHF3,CHF3+CF4,and CHF3+O2as etching gases.The relationship between different etching gases and the three parameters of etching rate,uniformity and selectivity was researched.By comparing the different etching results and optimizing the ratio of different gases,the optimized etching process were obtained with the etching rate as 119 nm/min,the uniformity as 0.6% and the PR selectivity as 3.62.