用ECRCVD方法制备优质氮化硅钝化膜

Silicon nitride passivation films prepared by ECRCVD

利用电子回旋共振等离子体化学气相沉积(ECR-CVD)技术,以SiH4和N2为反应气体进行了氮化硅钝化薄膜的低温沉积技术的研究。采用原子力显微镜、傅立叶变换红外光谱和椭圆偏振光检测等技术对薄膜的表面形貌、结构、厚度和折射率等性质进行了测量。结果表明,采用ECR-CVD技术能够在较低的衬底温度条件下以较高的沉积速率制备厚度均匀的氮化硅薄膜,薄膜中H含量很低。薄膜沉积速率随微波功率和混合气体中硅烷比例的增加而增大。折射率随微波功率的增大而减小,随混合气体中硅烷比例的增大而增大。在相同气体混合比和微波功率条件下,较高衬底温度条件下制备的薄膜折射率较大。

The technology of depositing silicon nitride passivation films was developed by using electroncyclotron resonance chemical vapor deposition technology with different mixture of silane and nitrogen asreaction gases. The effects of experimental parameters on the film characteristics were studied. Atomicforce microscope, Fourier transform IR spectrum and spectral ellipsometry technology were employed tocharacterize the films' topology, chemical bonding structure, film thickness and refractive index. Results show that uniform silicon nitride films with low hydrogen content can be deposited at high deposition rateunder low substrate temperature. The deposition rate increases with microwave power and silane-to-nitrogen flow ratio. The refractive index decreases with microwave power and increases with silane-to-nitrogen flow ratio. At higher substrate temperature, the refractive index also increases.