Structures Analysis And Luminescence Characteristics Of Amorphous SiN_x Films Prepared By Magnetron Sputtering

In the last decade, the silicon-based nanomaterial has grown to be a span-new photoelectron communications material, which is important in light-emitter and photo-electronic integration technology. Efforts have been devoted to study the PL and EL origin of silicon nanocrystals embedded in a Si-rich oxide matrix or Si/SiO₂ superlattice due to quantum confinement effect (QCE). However, a-SiN_x films are regarded as ideal candidates for the study of PL in silicon-based compound due to its wide gap (about 5.3eV), strong light emission and lower barriers for electrons and holes than silicon oxide.In this paper, amorphous SiN_x films were deposited on Si substrates by magnetron sputtering technology. The mechanism of deposition and inner structure of amorphous SiN_x films with different sputtering power and annealing temperature during preparation were studied by FTIR spectra and XPS measurement. One absorption band of the SiN_x films which was assigned to the stretching vibration mode of Si-N-Si bond was detected by Fourier transform infrared (FTIR) spectroscopy. It showed that a red shift for the absorption peak occurred in the FTIR spectrum with the increasing of sputtering power; Nevertheless, a blue shift for the absorption peak occurred after annealing. The phases of SiN_x films were separated into Nc-Si and Si₃N₄ at high temperature. According to XPS analysis, the structures of Si-N-Si₃, Si-N₂-Si₂, Si-N₃-Si and Si-Si₄ were formed in SiN_x films.Further more, the PL and EL mechanism was studied according to the spectra of annealed samples.