Photoluminescence of Si/SiO2 and SiNx/SiO2 multilayers

Si/SiO2 and SiNx/SiO2 multilayers were prepared on Si(100) at room temperature by radio-frequency (RF) magnetron sputtering. The optical properties of these films were investigated using Fourier transform infrared (FTIR) absorption and photoluminescence (PL) spectra. Strong photoluminescence at 374 nm and 712 nm is observed. The quantum confinement-luminescence center (QCLC) model is adopted to interpret the PL results. The two PL peaks at 374 nm and 712 nm are attributed to the luminescence center of defect states at the SiOx interface. On the other hand, it is suggested that the peaks appeared at 440 nm and 485 nm after annealing be related to the N-Si-O and Si-O-Si defect states level.