Self-assembling formation of silicon quantum dots by low pressure chemical vapor deposition

The growth of Si dots on thermally-grown SiO2/c-Si from a thermal decomposition of pure silane has been systematically studied in the temperature range from 500 to 650 degrees C. It has been suggested that the Si dot height and dot diameter on as-grown SiO2 are rate-limited by the cohesive action of adsorbed precursors and the thermal decomposition of silane on Si nucleation sites, respectively. The nucleation site on as-grown SiO2 is likely to be generated by the thermal dissociation of surface Si-O bonds. It has been also found that in Si dot formation on OH-terminated SiO2 surface the nucleation density is dramatically enhanced and consequently the dot size and its distribution become small. This implies that surface OH bonds can provide the nucleation sites.