Investigation of Optical Mechanisms of Silicon Nanoclusters Embedded in Silicon Nitride

Silicon nanoclusters embedded in silicon nitride matrix have been widely studied, those films must be grown or annealed at high temperature. In this work, we used a novel designed laser-assisted plasma enhanced chemical vapor deposition system (LAPECVD) to grow silicon nanostructure embedded in silicon nitride films at room temperature and without post-annealing process. The photoluminescence (PL) property of the laser-assisted films is different from the films grown without laser assistance. A detailed analysis of the PL property from silicon nitride film is reported. The PL spectra of the laser-assisted silicon nitride films originated from the quantum confinement effect of silicon nanoclusters. Moreover, the PL spectra of the silicon nitride films grown without laser assistance originated from defects in the silicon nitride films. The function of CO2 laser will be studied in this work. A direct verification of silicon nanoclusters embedded in the silicon nitride films was examined using a high resolution transmission electron microscope (HRTEM) image. The light-emission mechanism of the Si nanocluster embedded in silicon nitride films grown using CO2 laser will be proposed and proved in this work.