Precipitation and crystallization of nanometer Si clusters in annealed Si-rich SiO2 films

Si-rich SiO2 films with three different degrees of Si-richness were deposited by RF magnetron sputtering using Si-SiO2 composite targets. X-ray photoelectron spectroscopy measurements indicate that Si clusters were present in the as-deposited films. The precipitation and crystallization of nanometer Si clusters in SiO2 films annealed at high temperatures have been studied using high-resolution transmission electron microscopy and electron diffraction. Si nanocrystallites were observed in the sample deposited using a Si-SiO2 composite target having a 30% area of Si and which had been annealed at 900 degrees C. The average size and density of Si nanocrystallites in the films increased notably as the annealing temperature was increased from 900 to 1100 degrees C, Thus, using a 1100 degrees C anneal and increasing the area percentage of Si in the composite target from 20 to 30%, the average size of Si nanocrystallites increased about 15%, and the density of Si nanocrystallites increased by a factor of about 2.5. (C) 2000 Elsevier Science B.V. All rights reserved.