Doping of nitrogen in Li-Al doped ZnO by RF magnetron sputtering

ZnO and Li-Al co-doped ZnO thin films were grown on c-plane Al ₂O ₃ at a growth temperature of 500°C with a N ₂O pressure of 10 mTorr by using RF magnetron sputtering. The composition of the sputtering targets consisted of (1 - x)ZnO + x(LiO _0.5 + AlO _1.5) (x = 0, 2.5, 5, 10, 15). The Li-Al co-doped ZnO were observed to be a single phase with a hexagonal wurtzite structure. The solubility of (LiO _0.5 + AlO _1.5) in the ZnO thin films was estimated to be more then 15 mol%. The incorporation of nitrogen in the ZnO thin film grown using RF magnetron sputtering was enhanced with increasing co-doped amount of (LiO _0.5 + AlO _1.5). The main nitrogen defect in the ZnO thin films was a single N atom substituting at the O site (N _o), which could be an acceptor.