Study on The Performance of PECVD Silicon Nitride Thin Films

Abstract

Mechanical properties and corrosion resistance of Si 3 N 4 films are studied by using different experiment parameters, such as plasma enhanced chemical vapor deposition (PECVD)RF power, ratio of reaction gas, reaction pressure and working temperature. The etching process of Si 3 N 4 is studied by inductively coupled plasma (ICP) with a gas mixture of SF 6 and O 2 . The influence of the technique parameters, such as ICP power, DC bias, gas composition, total flow rate, on the etching selectivity of Si 3 N 4 /EPG533 which is used as a mask layer and the etching rate of Si 3 N 4 is studied, in order to get a better etching selectivity of Si 3 N 4 /EPG533 with a faster etching rate of Si 3 N 4 . The optimized process parameters of etching Si 3 N 4 by ICP are obtained after a series of experiments and analysis. Under the conditions of the total ICP power of 250 W, DC bias of 50 W, total flow rate of 40 sccm and O 2 composition of 30%, the etching selectivity of 2.05 can be reached when Si 3 N 4 etching rate is 336 nm/min.