Deep Level Emission of ZnO and Amorphous SiOC Films by Photoluminescence

Abstract

Effect of polarity in substrate for ZnO growth was researched. The zinc oxide films were deposited on SiOC/Si wafer by a RF magnetron sputtering system. SiOC film was also deposited by RF magnetron sputtering to obtain a low temperature process. Polarity in SiOC film changed with increasing the oxygen gas flow rates, and the chemical shift in the PL spectra was observed because of lowering the polarity of SiOC film caused by chemical reactions between CH group and OH group as the polar sites by high plasma energy. The chemical shift after ZnO deposition on SiOC film made was attributed to defects owing to the Vo and Zni and the valence band in ZnO at interfaces between ZnO and SiOC films. ZnO grown on SiOC film including polar sites changed the roughness owing to the induction of the trap charge resulted from the defects. The roughness of ZnO increased at SiOC with low polarity. SiOC with polar sites enhanced the level of blue emission deeply, and showed the blue shift in PL spectra.