CVD-based Polytype Controlled SiC Nanowire Growth

A novel chemical vapor deposition (CVD) based step-flow epitaxy process is proposed for controllable growth of SiC nanowires with high polytype integrity. SiC nanowires will be grown in a modified commercial high-temperature CVD reactor, used by industry for growing high-quality SiC epitaxial thin films. Different polytypes of SiC nanowires will be grown by choosing appropriate substrate materials as well as tuning the Si/C molar ratio in the precursor species. The nanowires will be grown on off-oriented substrates, in an attempt to ensure polytype purity. Various techniques for controlling the diameter, orientation and doping type / concentration of the SiC nanowires will be explored. Several strategies for patterning the nanowires on specific locations on the substrates will be investigated. Finally, a prototype gas sensor device will be constructed using the SiC nanowires grown in this project. This gas sensor will allow the detection of greenhouse gasses like Nitrous Oxide and CO2 with extremely high sensitivity.