Layer-by-layer oxidation of InN(0001) thin films into body-center cubic In2O3(111) by cycle rapid thermal annealing

• Main Authors: Liu, H. F., Chi, Dong Zhi, Liu, Wei
• Other Authors: School of Electrical and Electronic Engineering
• Format: Article
• Language: English
• Published: 2013
• Subjects: DRNTU::Engineering::Electrical and electronic engineering
• Online Access: https://hdl.handle.net/10356/95618; http://hdl.handle.net/10220/10823
• Institution: Nanyang Technological University

We report on a study of In2O3 thin films obtained by post-growth thermal oxidation of InN(0001) using rapid thermal annealing (RTA) and cycle-RTA (CRTA). The crystal qualities of both the resultant In2O3 and the remaining InN were significantly improved by using CRTA instead of RTA. Body-center cubic (bcc) In2O3, consisting of two In2O3(111) variants in-plane rotated 60° with respect to each other, was epitaxially grown on InN(0001). The in-plane orientations were determined as In2O3[01[1 with combining macron]]//InN[11[2 with combining macron]0] and In2O3[01[1 with combining macron]]//InN[[1 with combining macron]2[1 with combining macron]0] for the two In2O3(111) variants. Microscopic and spectroscopic analyses, together with the effect of Si3N4 encapsulations, provide evidence that the oxidation of InN is realized by oxygen inward diffusion. The oxygen inward diffusion is slowed down and the thermal decomposition of InN is suppressed by using CRTA, which in turn leads to a layer-by-layer oxidation of InN.