The performance and negative bias illumination stability of Hf-In-Zn-O thin film transistors on sputtering conditions

Abstract

This study examined the performance and stability of amorphous Hf-In-Zn-O (a-HIZO) thin film transistors (TFTs) with different sputtering conditions (DC and RF) for the active layer. The field-effect mobility and stability under negative bias illumination stress for the DC device significantly improved to 13.7 cm(2)/Vs and -1.5 V shift of threshold voltage, respectively, compared to those (2.4 cm(2)/Vs and -2.4 V shift) for the RF device. It is suggested that the incorporation of hydrogen into the RF-sputtered HIZO film has generated larger defect states in the vicinity of the HIZO/gate insulator interface, which may act as hole trap centers. This work demonstrates that the oxide TFTs combined with DC magnetron sputtering will be a prominent candidate for commercial production of the TFT backplane toward next-generation display applications.