OXIDATION OF SI1-YCY ESS-THAN-OR-EQUAL-TO-Y-LESS-THAN-OR-EQUAL-TO-0.02) STRAINED LAYERS GROWN ON SI(001)

We have studied wet thermal oxidation between 700 and 1100 degrees C o f strained Si1-yCy (0 less than or equal to y less than or equal to 0. 02) layers grown by molecular beam epitaxy on Si(001) substrates. The oxidation kinetics and the refractive indices of the oxides grown on S i1-yCy were monitored by ellipsometry. They show no significant differ ences in comparison with oxides grown on silicon. Secondary ion mass s pectroscopy and x-ray photoelectron spectroscopy reveal the appearance of carbon in the oxide. To find an appropriate temperature window for oxidation, we investigated the underlying Si1-yCy layers after oxidat ion by infrared absorption measurements. We observed a decrease of the substitutional carbon concentration for oxidation temperatures higher than 800 degrees C. Thus, only a small temperature window for the gro wth of good thermal oxide on Si1-yCy layers is available. Infrared abs orption measurements on the oxide vibrational modes reveal a small inf luence of the carbon concentration on the structural quality of the ox ide. (C) 1998 American Vacuum Society.