4H-silicon carbide wafer surface after chlorine trifluoride gas etching

Abstract

In order to develop the high etching rate reactor for silicon carbide, the C-face 4H-silicon carbide wafer, having the diameter of 50 mm, was etched by the chlorine trifluoride gas at 500 oC. By the deep etching, the concentric-circle-shaped valleys were observed at the positions corresponding to the radii of the pin-hole arrays of the gas distributor, as predicted by the calculation. The etching rate profile of 4H-silicon carbide was concluded to have a relationship with the local chlorine trifluoride gas supply. The wafer distortion was small even very thin, about 160 μm thick.