Effect of argon flow on promoting boron doping for in-situ grown silicon nitride thin films containing silicon quantum dots

Abstract Boron-doped silicon nitride thin films (SiN _x ) containing silicon quantum dots (Si QD) were prepared in situ by plasma enhanced chemical vapor deposition. With the aim of optimizing the performance of thin films, the mixed gas including argon and hydrogen was applied as dilution. The effects of Ar flow on the structural, electrical and optical properties of B-doped SiN _x thin films were systemically studied through various characterizations. By tuning the Ar flow, the properties, such as QD size, crystallinity and optical band gap, can be effectively controlled. The B-doping efficiency in thin films was proved to be promoted by introducing moderate Ar flow. The maximum values of dark conductivity (1.52 S cm ⁻¹ ) and carrier concentration (2.41 × 10 ¹⁹ cm ⁻³ ) were obtained for the B-doped SiN _x thin films at the Ar flow of 200 sccm. Furthermore, the mechanism on the promotion in B-doping was illustrated in detail in this paper.