Effect of oxidation temperature on physical properties of thermally grown oxide on GaN in N2O ambient

Thermal oxidation of AlGaN nanowires for sub-250 nm deep ultraviolet photodetection

“…After 5 h of oxidation, the peak intensity of AlGaN nanowires is almost the same as that of 3 h of oxidation, suggesting that oxidation degree of AlGaN nanowires has saturated. When the oxidation temperature was less than 700 • C, only Al-N bond in AlGaN nanowire can be oxidized, and the Ga-N bond cannot be oxidized [26,27]. In other words, the AlGaN nanowires were transformed into AlGaON.…”

“…Previous studies on the oxidation process of GaN have suggested that GaN was scarcely oxidized below 700 • C in an oxygen atmosphere. The Ga-N bond cannot be easily broken because there was no change in the XRD peak before and after oxidation [13,26,27]. However, when the temperature was elevated to above 700 • C, the GaN can be oxidized gradually by increasing the temperature and time.…”

Atomic structure analysis of gallium oxide at the Al2O3/GaN interface using photoelectron holography

“…Therefore, in recent years, the control of the oxidation state of the interface and the atomic arrangement have been reported. 4,[19][20][21][22][23][24][25] In particular, the gallium oxide layer has been analyzed by X-ray photoelectron spectroscopy (XPS) 26,27) and observed by cross-sectional transmission electron microscopy (TEM). 9,[28][29][30][31] Although many crosssectional TEM observations have been reported, making a detailed analysis of the interface between the amorphous and crystalline layers is difficult because of the damage that occurred during the sample preparation and crystallization of the material; this damage was caused by electron beam irradiation of Al 2 O 3 /GaN.…”