DC sputter deposition of amorphous indium–gallium–zinc–oxide (a-IGZO) films with H2O introduction

Abstract Amorphous indium–gallium–zinc–oxide (a-IGZO) films were deposited by dc magnetron sputtering with H 2 O introduction and how the H 2 O partial pressure (P H 2 O ) during the deposition affects the electrical properties of the films was investigated in detail. Resistivity of the a-IGZO films increased dramatically to over 2 × 10 5 Ωcm with increasing P H 2 O to 2.7 × 10 − 2 Pa while the hydrogen concentration in the films increased to 2.0 × 10 21 cm − 3 . TFTs using a-IGZO channels deposited under P H 2 O at 1.6–8.6 × 10 − 2 Pa exhibited a field-effect mobility of 1.4–3.0 cm 2 /Vs, subthreshold swing of 1.0–1.6 V/decade and on–off current ratio of 3.9 × 10 7 –1.0 × 10 8 .