Optical investigation of bulk electron mobility in 3C-SiC films on Si substrates

The dependence between the carrier concentration and electrical mobility has been studied by micro-Raman spectroscopy in n-doped 3C-SiC films grown on (111) and (100) Silicon oriented substrates. Bulk mobility varies between 10 and 510 cm(2) V-1 s(-1) for a carrier concentration ranging between 1.6 X 10(16) and 5.4 X 10(18) cm(-3). Local stacking variations observed on the (111) 3C-SiC surface lead to a worse crystal morphology compared to (100) 3C-SiC films resulting in a decrease in the average bulk mobility. Defects are thus accountable for the dependence between mobility and carrier concentration for different 3C-SiC orientations.