Effects of Annealing Ambient on the Characteristics of LaAlO(3) Films Grown by Atomic Layer Deposition

We investigated the effects of different annealing ambients on the physical and electrical properties of LaAlO(3) films grown by atomic layer deposition. Post-grown rapid thermal annealing (RTA) was carried out at 600 °C for 1 min in vacuum, N(2), and O(2), respectively. It was found that the chemical bonding states at the interfacial layers (ILs) between LaAlO(3) films and Si substrate were affected by the different annealing ambients. The formation of IL was enhanced during the RTA process, resulting in the decrease of accumulation capacitance, especially in O(2) ambient. Furthermore, based on the capacitance-voltage characteristics of LaAlO(3)/Si MIS capacitors, positive V (FB) shifting tendency could be observed, indicating the decrease of positive oxide charges. Meanwhile, both trapped charge density and interface trap density showed decreased trends after annealing treatments. In addition, RTA process in various gaseous ambients can reduce the gate leakage current due to the enhancement of valence band offset and the reduction of defects in the LaAlO(3)/Si structure in varying degrees.