CMOS Compatible Growth of High Quality Ge, SiGe and SiGeSn for Photonic Device Applications

Germanium films were deposited on silicon substrate by an ultra-high vacuum chemical vapor deposition system using GeH 4 as Ge precursor and different carrier gases (Ar, N 2 and H 2 ). Silicon-germanium and SiGeSn films were deposited using optimized growth conditions of Ge growth. Silane and SnD 4 were used as precursors for Si and Sn, respectively. A complete study of SiGe growth at chamber pressure from 0.1 to 1.0 torr and at temperatures from 350-450ºC for different SiH 4 flow rate is performed. Silicon incorporation in Ge films varied from 1% to 17%. Tin incorporation of 2% was observed in the films with 17% Si incorporation. Investigation of film quality has been done using etch pit measurement, scanning electron microscopy and transmission electron microscopy. Threading dislocation density for Ge, SiGe and SiGeSn films were 1.7×10 7 cm -2 , 2.3 ×10 7 cm -2 and 4.0 ×10 7 cm -2 , respectively.