Plasmaless etching of silicon using chlorine trifluoride

Abstract

Silicon etching using ClF3 gas has been carried out at various substrate temperatures from −20 to 120 °C. The etching properties (etch rate, pressure effect, and surface morphology) depend remarkably on the temperature. Based on the mass spectroscopic measurements, SiF4 is specified as a main product. The minor product SiF2 is also found, and the ratio of the signal intensity of SiF2 to that of SiF4 decreases with temperature. From Auger electron analyses on the etched surface, the density of fluorine atoms on the surface decreases with increasing the temperature. It is concluded that the density of the fluorosilyl species greatly influences the etching reaction process.