Phase transition of hydrogenated SiGe thin films in plasma-enhanced chemical vapor deposition

The phase transition of hydrogenated SiGe (SiGe:H) films in plasma enhanced chemical vapor deposition was investigated by varying Ge content and hydrogen dilution ratio, R; the phase transition was then compared with that of hydrogenated Si (Si:H). The incorporation probability of Ge in SiGe:H films was strongly affected by R and continuously increased when R ranged from 7.5 to 80. The incorporation of Ge might interfere with the formation of crystalline seeds in the film due to the increase of disorder. However, once the crystalline seeds are formed in the SiGe:H films, the crystalline volume fraction increased with R more rapidly than that did for Si:H films. •Incorporation probability of Ge in SiGe:H was increased with H2 dilution ratio.•Crystalline phase diagram of SiGe:H films according to Ge content and H2 dilution•Adding Ge into Si:H requires a high H2 dilution for forming microcrystalline phase.•Microcrystallization of SiGe:H proceeds more rapidly compared to that of Si:H.