SiGe:H THIN FILMS PREPARED BY PLASMA ASSISTED REACTIVE THERMAL CHEMICAL VAPOR DEPOSITION

摘要

In this work, very high frequency plasma assisted reactive thermal chemical vapor deposition (VHFPA-RTCVD) technology is applied to prepare SiGe:H thin films on a low-temperature substrate. The structural properties of SiGe:H thin films are investigated with varying H2 dilution for different germanium concentrations (GCs). The absorption coefficient, photo-conductivity and dark-conductivity of SiGe:H thin films in different phases are also measured. We observed that under the same hydrogen dilution the growth rates of SiGe:H thin films almost keep unchanged with the increase of GC. And we also observed that transition from microcrystalline to amorphous growth happens easier in the lower GC while comparing with the higher GC of SiGe:H alloys. Moreover, we found that with the increase of germanium incorporation into alloys, the photoconductivity decrease firstly and consequently ascend, and dark conductivity keeps an ascending trend.