SiSn mediated formation of polycrystalline SiGeSn

Abstract

Abstract Si1–x Sn x and Si1–x– y Ge x Sn y polycrystalline thin layers were grown using Sn nanodots as crystal nuclei. Si1–x Sn x crystallization occurred around Sn nanodots, and the substitutional Sn content was estimated as high as 1.5%. In the case of the poly-Si1–x– y Ge x Sn y , Ge and Si were deposited simultaneously on the Sn nanodots, however, Ge was preferentially incorporated into the Sn nanodots, resulting in the formation of the poly-Si1–x– y Ge x Sn y with amorphous Si residue. It was found that the poly-Si1–x Sn x formed by the Sn nanodots mediated formation can be used as the new virtual substrate to be alloyed with Ge, namely the 2-step formation process consisting of poly-Si1–x Sn x crystallization and Ge alloying with the poly-Si1–x Sn x is the effective process for the poly-Si1–x– y Ge x Sn y formation. This non-equilibrium process with achieving crystallization resulted in the substitutional Si and Sn content in the as-grown poly-Si1–x– y Ge x Sn y as high as 10.8% and 3.5%, respectively.