Low-temperature deposited highly-conductive SiC films has long been a goal for many researchers involved in hetero-junction bipolar transistor, thin-film transistor, solar cell.… etc. Here in this paper, we study the influences of the diluted PH3 flow rates on SiC film quality as well as electrical properties. PH+ was determined from residual gas analyzer to be the main dopant source. Phosphorous atoms will play a role of enhancing the SiC grain growth and resulting in a smaller film growth rate. Carrier concentrations increase monotonically with the diluted PH3 flow rates. While Hall mobility first increases than decreases with it due to a combination effect of the impurity scattering and a film quality improvement which dominates when the 1% PH3/H2 flow rate is above or below 40 seem, respectively.

Polycrystalline β-SiC, with grain size up to 0.2 μm, was grown on silicon substrate by electron cyclotron resonance chemical vapor deposition (ECR-CVD) from SiH4/CH4/H2 at 178–500 °C. The nucleation process and surface structure of polycrystalline SiC were investigated via observing the film surface by atomic force microscopy (AFM). Reaction species which promote polycrystalline SiC was in-situ monitored by quadruple mass spectrum analysers during deposition process, which is crucial for the control of polycrystalline SiC growth. The microstructure of SiC films were inspected by bright-field imaging, dark-field imaging, and electron diffraction in cross-sectional transmission electron microscopy. This paper will also discuss the key parameters for the nucleation and growth of polycrystalline β-SiC at very low temperature in ECR-CVD system.

Microcrystalline β-SiC films were deposited on silicon substrates by electron cyclotron resonance chemical vapor deposition (ECR-CVD) at 500°C utilizing a SiH4-CH4-H2 gas mixture. The effects of two important parameters on film growth, SiH4/CH4 flow ratio and microwave (MW) power, were investigated using X-ray photoelectron spectroscopy (XPS) along with the Fourier transform infrared spectra (FTIR). Results showed that the optimum flow ratio is about 0.5. Under the optimum flow ratio, a large MW power is favorable for the growth of high quality films with an ideal film stoichiometry. Surface morphology inspected by the contact mode atomic force microscopy (AFM) reveals that high MW powers not only improve the film crystallinity but also increase its surface roughness as well.