Transformation of SiOx films into nanocomposite SiO2(Si) films under thermal and laser annealing

Abstract

Oxide-assisted growth of Si nanocrystals includes deposition of a silicon-enriched SiO x film at the first stage and annealing at the second one. The ion-plasma sputtering method has been used for deposition of the SiO x film. The influence of thermal and laser annealing on SiO x film properties has been investigated. Formation of silicon nanoislands on oxide film surface has been observed by AFM both after thermal and laser annealing. The height and surface density of the nanoislands depends both on the silicon content in the initial SiO x film and temperature of thermal annealing. The higher annealing temperature causes formation of large nanoislands, but their surface density decreases. Comparison of nanoislands created at thermal and laser annealing shows that in case of laser annealing the nanoislands are higher and their surface density is lower. The intensity of laser irradiation influences on nanoisland parameters significantly. The growth of electrical conductivity with thermal annealing temperature has been observed. The influence of gas atmosphere during annealing is also significant in case of higher temperatures. In case of laser annealing at the beginning at low laser irradiation intensities, the SiO x film conductivity increases, but the following growth of intensity causes the decrease in electrical conductivity.