X-ray photoelectron spectroscopy(XPS) and a closed sample holder were used to study the intrinsic surface of silicon following etching of silicon oxide by the liquid and gas phases of HF. The XPS analyses showed that the surface atoms of silion wafer consisted of Si, C, O and F after the various etching processes. The process of anhydrous HF gas in conjugation with $CH_3$OH vapor resulted in lower concentrations of carbon and oxygen than other processes. The etching process using only the anhydrous HF gas could nto completely remove the oxide film on the surface, because it might be resulted form the depletion of $H_2$O adsorbed on the suface due to the hydrophobic property of silicon suboxide(SiOx : < 2) near the silicon surface. Also, the degree of fluorination of the oxide surface was greater than the silicon surface. Fluorine atoms were very sensitive to air exposure, narrow scan spectra of Fls could be deconvoluted into three peaks ; ~686.0, ~687.4. and ~690.0 V. The binding environments were asigned to Si-Fx(x=1 or 2) at ~686.0 eV, SiOxF(x${leqq}$1.5) at ~687.4 eV, and a highly fluorinated silicon oxide, SiOxFy(y${geqq}$2) at ~690.0 eV.