Effect Of Sio2(1.2 Mu M)/Ti-Foil Substrate Nitridation On Gan Thin Films Grown By Reactive Evaporation Method

The effect of the plasma nitridation of the SiO2(1.2 mu m)/Ti-foil substrate on the quality of the GaN thin films grown by the reactive evaporation method was investigated. Highly c-axis oriented GaN(0002) thin films were obtained. In contrast to the case without nitridation, the quality of GaN(0002) crystals with substrate nitridation was improved. This can be attributed to the flattened surface of the intermediate SiO2 layer and the passivation of Si and O dangling bonds during the substrate nitridation. Photoluminescence measurements show that the emission at the near-band edge (about 3.15 eV) is detected when nitridation occurs whereas only deep level emission is observed when no nitridation occurs.