Deep level transient spectroscopy was used to detect the presence of deep levels correlated to the defects induced in the Si substrate by a CHF3/Ar dry etch of a 550 Angstrom gate oxide as a function of the rf power. Several energy levels were observed; some of them were due to the processing before the dry etching. Three traps produced by the dry etching, with Arrhenius plot activation energies, respectively, E-nal = 350 meV, E-na2 = 220 meV, and E-na3 = 100 meV, and capture cross sections around 10(-20) cm(2) were detected. The correlation with the surface recombination velocity variations and the F and C diffusion in the Si substrate was investigated.