关键词: 微机械加工, 低压化学气相淀积, 低应力氮化硅, 均匀性

Abstract: In order to flatten the bow of wafers, low stress silicon nitride is often used in the micro-electro mechanical system as structural layer materials or passivation films. We can obtain the silicon nitride films whose stress are under 200 MPa pascal through optimizing the ratio of the reaction gases in low pressure chemical-vapor deposition. Bad wafer to wafer non-uniformity of films’ stress and thickness is an important process problem. We analyzed that the change of ratio caused by the consumption of the reaction gases is the main factor in the method of using secondary ion mass spectroscopy (SIMS). By optimizing the process parameters, we can obtain the silicon nitride films whose wafer to wafer stress is between 100 to 150 MPa Pascal and thickness non-uniformity is below 5%. And we can also realize the process capability of 50 wafers per furnace, which can be used in micro-electro mechanical system process in the future.

Key words: micro-electromechanicalsystem, lowpressurechemical-vapordeposition, lowstresssiliconnitride, un-uniformity