The surface of silicon in hydroflouric acid (HF) is coated with covalently attached hydrogen (SiHxgroups, withx=1,2,3), with probably a very small concentration of SiF bonds. In contrast with a recent claim by Niwano &etal; [J. Appl. Phys.79, 3708 (1996)], we show that the concentration of SiF bonds is as yet beyond infrared detection limits. Our analysis indicates that the band at2230 cm−1observed by these authors actually arises from electrolyte absorption. ©1997 American Institute of Physics.