Electrical characteristics and the x-ray photoelectron spectroscopy of AlN/InP structure fabricated by helicon-wave-excited plasma nitridation of vacuum-evaporated Al

Aluminum nitride/n-type InP (100) metal-insulator-semiconductor (MIS) structures were fabricated by helicon-wave-excited plasma nitridation of vacuum-evaporated Al on an InP substrate. Nitridations were performed in both N-2 plasma and N-2 + Ar mixed plasma. For comparison's sake, the Al/InP structure was exposed to the helicon-wave-excited Oz plasma to fabricate the Al2O3/InP MIS structure. Relatively good capacitance-voltage (C-V) characteristics were obtained for the Nz-plasma-treated Al/InP sample, which were superior to those obtained for the O-2-plasma-and N-2 + Ar-mixed-plasma-treated ones. The leakage current was also the smallest for the N-2-plasma-treated sample. X-ray photoelectron spectroscopic (XPS) measurements indicated that AlN and/or AlNxOy was formed nearly throughout the entire film depth in both N-2-and N-2 + Ar-plasma treatments,while Al2O3 was found to be formed in the case of the O-2-plasma treatment.