Annealing Effect on Electronic Properties of Transparent Oxide Semiconductor Ga-In-Zn-O (GIZO) Thin Films

Abstract

The effect of temperature annealing on electronic properties of Ga-In-Zn-O (GIZO) have been\ud studied quantitatively by use refelection electron energy loss spectroscopy (REELS), X-ray photoelectron\ud spectroscopy (XPS) and extended X-ray absorption fine structure (EXAFS) spectroscopy.\ud The bandgap value of GIZO were obtained as a function of temperature annealing from the\ud REELS spectra The band gap changes from 3.1 eV as deposited to 4.2 eV for annealing at 800oC.\ud The composition of element and chemical bonding in GIZO thin films were obtained by XPS and\ud EXAFS, respectively. The K-edge spectra by EXAFS were observed with sharp absorption edges\ud at 10.37 keV for Ga and 9.66 keV for Zn for GIZO thin films. The composition by XPS shows Ga\ud increase and Zn reduce while temperature annealing increase and will become GIO thin films for\ud 800oC. The composition changed as a function of temperature that impact to the electronic properties\ud of GIZO thin films are investigated