High rate synthesis of crystalline silicon films from SiH4+He using high density microwave plasma

Abstract

By using a high density microwave-induced plasma source, depositions of crystalline silicon films from SiH4+He mixture are investigated systematically. Microwave power and SiH4 flow rate are used as the variable deposition parameters. Results demonstrate that film deposition rate increases with increasing both the microwave power and the SiH4 flow rate. While film crystallinity promotes with increasing the microwave power but degrades with increasing the SiH4 flow rate. After optimizing the film deposition conditions, highly crystallized Si films are deposited at a rate higher than 1000 nm/s. Promotion of the dissociation efficiency of source gases and enhancement in the diffusion length of film precursors on growing surface are suggested to be main factors responsible for the simultaneous achievements of the high deposition rate and the high film crystallinity. Mechanisms under these phenomena are discussed in detail.