HYDROGEN MOLECULES IN DEFECTIVE SILICON

Hydrogen molecules are formed in crystalline silicon treated with atom ic hydrogen. We have investigated the effect of defects in silicon on the formation of hydrogen molecules. Raman measurements were taken on crystalline, microcrystalline and amorphous silicon after treatment wi th atomic hydrogen. A vibrational line of Hz was observed in crystalli ne and microcrystalline silicon after treatment with atomic hydrogen. The intensity of the vibrational line in microcrystalline silicon is a pproximately one fifth of that observed in crystalline silicon. No Ram an signals due to Ha were detected in either amorphous Si:H or amorpho us silicon produced by ion implantation. These results suggest that hy drogen molecules observed in hydrogenated crystalline silicon are trap ped in the interstitial sites in nondamaged crystals of silicon.