A Comparison of Various Surface Finishes and the Effects on the Early Stages of Pore Formation during High Field Etching of SiC (original) (raw)

Effect of electrochemical etching solution composition on properties of porous SiC film

Journal of Physics: Conference Series, 2009

Porous amorphous SiC (a-SiC) layer with pore size in the nanometer region was fabricated on the a-SiC/Si substrates by the electrochemical etching method using HF/H2O/surfactant solution. Systematic study showed that the HF concentration in the etching solution (in the 1-73% region) strongly affects the structure (both the pore size and the pore density) of the porous a-SiC layer. It was also observed the changing of the photoluminescence properties of the porous a-SiC layer when its structure has been changed.

Metal assisted photochemical etching of 4H silicon carbide

Journal of Physics D: Applied Physics, 2017

Metal assisted photochemical etching (MAPCE) of 4H–silicon carbide (SiC) in Na2S2O8/HF and H2O2/HF aqueous solutions is investigated with platinum as metallic cathode. The formation process of the resulting porous layer is studied with respect to etching time, concentration and type of oxidizing agent. From the experiments it is concluded that the porous layer formation is due to electron hole pairs generated in the semiconductor, which stem from UV light irradiation. The generated holes are consumed during the oxidation of 4H–SiC and the formed oxide is dissolved by HF. To maintain charge balance, the oxidizing agent has to take up electrons at the Pt/etching solution interface. Total dissolution of the porous layers is achieved when the oxidizing agent concentration decreases during MAPCE. In combination with standard photolithography, the definition of porous regions is possible. Furthermore chemical micromachining of 4 H–SiC at room temperature is possible.