Energy band alignment of InGaZnO4/Si heterojunction determined by x-ray photoelectron spectroscopy

Abstract

X-ray photoelectron spectroscopy was utilized to determine the valence band offset (ΔEV) of the InGaZnO4 (IGZO)/Si heterojunction. The IGZO films were grown on Si (100) using radio frequency magnetron sputtering. A value of ΔEV = 2.53 eV was obtained by using In 3d5/2, Ga 2p3/2 core energy levels as references. Taking into consideration the experimental band gap of 3.20 eV of the IGZO, this would result in a conduction band offset ΔEC = 0.45 eV in this heterostructure.