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利用SiH4(80%Ar稀释)和CH4作为源气体,通过改变源气体流量比、基片温度、沉积气压等参量,使用微波电子回旋共振化学气相沉积法生长非晶碳化硅薄膜。实验结果表明碳化硅薄膜沉积速率随气体流量比R(CH4/(CH4+SiH4))的增加而减小、随基片温度的升高明显减小、随沉积气压的增加先增大后减小。红外结构表明:在较低流量比R下,薄膜主要由硅团簇和非晶碳化硅两相组成,而当R>0.5时,薄膜的结构主要由非晶碳化硅组成,薄膜中键合的H主要是Si和C的封端原子。同时,沉积温度的升高使碳化硅薄膜中Si-H,C-C和C-H键的含量减少,而薄膜中Si-C含量明显增加且峰位发生了红移。薄膜相结构的转变是薄膜光学带隙变化的原因。
Amorphous silicon carbide films were grown by microwave electron cyclotron resonance chemical vapor deposition using SiH4 (diluted with 80% Ar) and CH4 as the source gases by changing the parameters of source gas flow ratio, substrate temperature and deposition pressure. The experimental results show that the deposition rate of silicon carbide decreases with the increase of gas flow ratio R (CH4 / (CH4 + SiH4)), decreases with the increase of substrate temperature, and then increases with the increase of deposition pressure . The infrared structure shows that the thin film mainly consists of two phases of silicon clusters and amorphous silicon carbide at a low flow rate ratio R. When R> 0.5, the structure of the thin film mainly consists of amorphous silicon carbide. H is mainly the Si and C terminated atoms. At the same time, the deposition temperature decreases the content of Si-H, C-C and C-H bonds in the silicon carbide thin film, while the Si-C content in the film increases obviously and the peak position shifts red. The change of the film phase structure is the reason of the change of the optical band gap of the film.