A Phase Diagram of Low Temperature Epitaxial Silicon Grown by Hot-wire Chemical Vapor Deposition for Photovoltaic Devices
We have investigated the low-temperature epitaxial growth of thin silicon films by hot-wire chemical vapor deposition (HWCVD). Using reflection high energy electron diffraction (RHEED) and transmission electron microscopy (TEM), we have found conditions for epitaxial growth at low temperatures achieving twinned epitaxial growth up to 6.8 µm on Si(100) substrates at a substrate temperature of 230°C. This opens the possibility of growing high quality films on low cost substrates. The H_2:SiH_4 dilution ratio was set to 50:1 for all growths. Consistent with previous results, the epitaxial thickness is found to decrease with an increase in the substrate temperature.
Additional Information© 2005 Materials Research Society. The authors would like to thank BP Solar for their support on this project and CER would like to thank Corning for their NPSC Fellowship support. Thanks also to Bob Reedy at the National Renewable Energy Lab for his SIMS expertise which helped us to identify and resolve our contamination issues.