Impact of Excess Carbon at the 3C-SiC/SiO₂ Interface Using LPCVD-Based Alternating Supply Deposition

Abstract

We present for the first time alternative supply deposition (ASD) for the synthetization of polycrystalline 3C-SiC on Si/SiO2 substrates, thus representing an alternative route to silicon carbide on insulator (SiCOI). For this purpose, we investigated the differences in microstructure and electrical performance depending on whether a carbonization step (CS) is included or not. In comparison to 3C-SiC thin films deposited on pure Si with the same parameters we found an inhibited growth per cycle of 37 % on SiO2. For thin films grown on SiO2 without a CS we measured film resistivity values of ~6600 Ω·cm being four orders of magnitude higher, than those with a CS. High-resolution TEM images of the 3C-SiC/Si interface revealed the presence of an amorphous carbon layer, decreasing the overall 3C-SiC film resistivity.