SOFT-X-RAY STIMULATED ETCHING REACTION IN THE SF6 SIO2 ADSORPTION SYSTEM STUDIED BY NEURTAL PRODUCTS DETECTION/

Soft X-ray stimulated etching reactions in the adsorption systems SF6/ a-SiO2 and SF6/poly-Si at low temperature (approximately 100 K) have b een studied by the direct detection of neutral Products using a quadru pole mass spectrometer (QMS) in the 90-190 eV excitation energy range. The neutral products could be detected in a-SiO2, but not,in poly-Si. This is evidence that there is a high material selectivity. The yield curve of the SiF+ fragments which arised from SiF(x) neutral products in the SF6/SiO2 and the absorption spectrum of SF6/poly-Si were measu red. The peak positions of both spectra are similar. This suggests tha t the layers containing SiF(x) were initially produced on both surface s. The difference in reactivities between SiO2 and poly-Si can be ascr ibed to the desorption process of etching products from the reaction l ayers.