Formation of high-density Si nanodots by agglomeration of ultra-thin amorphous Si films

Abstract

High-density and similarly-sized Si nanodots were formed by annealing ultra-thin amorphous Si (a-Si) films deposited on SiO 2/Si substrates in vacuum. Dependences of density and diameter of the Si nanodots on the a-Si film thickness and, annealing temperature and time were investigated by scanning electron microscopy. It is found that drastic increase (decrease) in the density (diameter) occurred at an a-Si thickness of 1 nm. By agglomeration of sub-nanometer thick a-Si films, a density larger than 10 12 cm − 2 , an average diameter smaller than 5 nm, and a dispersion of diameter less than 15% were achieved.