Surface characterisation of inductively coupled plasma etched SiC in SF6/O2

An inductively coupled plasma (ICP) system has been used to dry etch 4H silicon carbide (SiC) substrate samples in SF6/O2 gas mixture. Under different etching conditions, etch rates have been studied. Dry etch-induced surface chemical bonding modifications have been systematically investigated using X-ray photoelectron spectroscopy (XPS). Various C–F bonds have been observed as etching products on the etched SiC surface. The increase of bias voltage and etch rate enhance not only the intensity of these C–F bonds but also the relative concentration of covalent C–F bonds on the etched SiC surfaces. Atomic force microscopy (AFM) results indicate that our etching process does not induce roughness on the etched surface even at higher bias voltages