Effect ofSndoping on the formation of silicon nanocrystal in silicon nitride films

Abstract

Sn-doped silicon nanocrystals (Si-NCs) embedded in silicon nitride was synthesized by post-annealing of silicon-rich silicon nitride (SRN) films deposited by co-sputtering. The effects of Sn impurity on the Si crystallization behavior and photoluminescence (PL) in SRN films were investigated. Doping with Sn dopants enhances phase separation in SRN and thus accelerates the crystallization of silicon nanoparticles. It was also found that the existence of Sn decreases crystallization temperature, and could be as low as 800 • C. In the Sn-doped samples, the crystalline volume fraction increases monotonically from 16.2% to 78.5% with increasing annealing temperature and the area densities of about ∼ 2.2 × 10 12 cm −2 can be achieved after annealing at 1100 • C. In addition, the intensity of PL of the SRN film could be enhanced by adding Sn impurity.