Atmospheric Pressure Chemical Vapor Deposition of 3C-SiC

In addition to its superior mechanical properties, the wide band gap (2.3 eV), high breakdown field, and high saturated electron velocity of cubic silicon carbide (3C-SiC) make it an attractive candidate for elevated-temperature, high-frequency, and high-power electronic devices. Optically transparent SiC deposits were grown via atmospheric pressure chemical vapor deposition (APCVD) on graphite substrates from methyltrichlorosilane (MTS) in hydrogen in a cold-walled, RF-induction furnace. Structural morphology was examined by scanning electron microscopy and correlated to substrate temperature, MTS/H{sub 2} ratio, and hydrogen flow. Photoluminescence revealed that high quality cubic material was grown. The PL spectra exhibited a zero phonon line (2.3787 eV) and attributable to an exiton bound to a neutral nitrogen donor, in addition to TA, LA, TO, and LO phonon replicas. Observed broadening and splitting of the PL spectral lines was associated with the morphological habit and internal strain of individual crystallites. In addition, the PL spectra for samples grown at higher MTS/H{sub 2} ratios and low H{sub 2} flows exhibited weak shoulders on the low energy side of the five-line spectra which might be associated with nonstoichiometric defects such as Si interstitials or C vacancies.