This study investigates bipolar resistance switching memory in a fabricated Pt/GaOx/TiN device. Gallium oxide sputtered in ambient Ar shows a change in resistance ratio of two orders of magnitude. The enhancement of resistance ratio is also observed in the gallium oxide layer when deposited in ambient Ar/O-2. The X-ray photoelectron spectroscopy analysis shows that this gallium oxide in ambient Ar/O-2 can reduce the number of defects and enhance the stability of switching behavior. An analysis of current transport mechanism in the high resistance state indicates that the larger effective thickness can be attributed to the higher oxygen concentration, and can increase the resistance value of the high resistance state. (C) 2012 Elsevier B.V. All rights reserved.