Controlling defect and Si nanoparticle luminescence from silicon oxynitride films with CO{sub 2} laser annealing

We demonstrate that a focused CO{sub 2} laser beam ({lambda}=10.6 {mu}m) can be employed to locally synthesize light emitting defects and Si nanoparticles in silicon rich oxynitride thin films. Films with a stoichiometry of SiO{sub 1.08}N{sub 0.32} were prepared by plasma enhanced chemical vapor deposition with N{sub 2}O and SiH{sub 4}. Strongly absorbing CO{sub 2} laser light was then used to induce local heating in the films in air ambient using power densities in the range from 0 to 580 W/cm{sup 2} and times of 5 s to 60 min. High-resolution cross sectional transmission electron microscopy (TEM) images of the irradiated region revealed the presence of crystalline Si nanoparticles. Photoluminescence (PL) spectra taken from irradiated areas showed two distinct peaks around 570 and 800 nm. From a combined TEM, Rutherford back scattering (RBS), forming gas annealing (FGA), PL, and PL lifetime study it is concluded that the 570 nm peak with a short PL lifetime (