为了获得应用于AlGaAs 激光器上的优异的氮化硅薄膜，采用等离子增强化学气相沉积(PECVD)低温条件下在GaAs 衬底上制备了不同参数的氮化硅薄膜，利用光学膜厚仪、原子力显微镜(AFM)、傅里叶变换红外光谱(FTIR)等技术对薄膜残余应力、表面形貌、折射率等进行了分析。结果表明，薄膜的残余应力随沉积功率的增加而变大；随气压先降低后变大，在200 Pa 时仅为6 MPa。薄膜的表面粗糙度随功率的提高而变大；随气压的提高而减小。功率和气压对薄膜的折射率影响不大，均在2.0~2.2 之间。薄膜中氢的存在形式为N-H 键。选择合适的功率和气压，可以在低温下获得极低应力和优异表面形貌的氮化硅薄膜。

In order to obtain the excellent silicon nitride (SiN) films in AlGaAs laser, SiN films with different deposition parameters are fabricated on GaAs substrate by plasma enhanced chemical vapor deposition (PECVD) at low temperature. The residual stress, surface morphology and refractive index of these films are investigated comprehensively by means of refractometer, atomic force microscope (AFM) and Fourier transform infrared spectroscopy (FTIR). The results show that residual stress of SiN films increases with the deposition power. An ultra low stress (6 MPa) is obtained at the pressure of 200 Pa. The AFM results show that the surface roughness increases with the deposition power, while decreases with the deposition pressure. Both the deposition power and the pressure have a weak effect on the refractive index. The refractive index of all these films are 2.0~2.2. The FTIR results show that the H element exists in the film with the N-H bond. SiN films with ultra low stress and good surface morphology can be obtained by selecting proper power and pressure at low temperature.