Formation of 3C-SiC films embedded in SiO2 by sacrificial oxidation

The formation of SiC on Insulator (SiCOI) using a tool wet sacrificial oxidation is studied. The wet oxidation in 3C-SiC is very anisotropic strongly depended on the defect density, especially the inversion domain boundaries (IDBs). The SiCOI structure was realized by depositing of 35 nm thick 3C-SiC film on (100)-Si substrate by APCVD subsequently the film was annealed by flash lamps. The flash lamp annealing system consists of Xe lamps powered by discharging capacitors producing pulses of 20 ms. After radiation two zones can be distinguished, upper and lower, exhibiting high and low defect density, respectively. The highly defected upper zone was etched by wet sacrificial oxidation at 1150°C for 16 min. forming a 50nm thick oxide layer on the top of a good quality, 20nm thick, 3C-SiC film. In parallel, a buried oxide layer having a mean thickness of 44nm was formed by oxidation of the Si substrate through existing channels created in the SiC by the preferential wet oxidation of the IDBs which touch the SiC/Si interface. Through the oxided channels the Si substrate is oxided fast forming a continuous buried oxide layer realizing the SiCOI structure.