Reliability analysis under bias stress and elevated temperature of dual-gate IGZO TFT

Indium–gallium–zinc oxide (IGZO) as a star material has been broadly applied in multiple functional devices, including planar displays, flexible electronic devices, and photoelectronics. In recent years, the development of artificial intelligence and great data also extends the application of IGZO-based thin film transistors (TFTs) to memory, memristors, and neuromorphic computing. Thus, the research of high performance and reliable IGZO TFTs attracts tremendous attention worldwide. Herein, a high-quality IGZO thin film was deposited via atomic layer deposition, and a dual-gate (DG) IGZO TFT was fabricated. Comprehensive electrical characterization was conducted on the fabricated DG IGZO TFTs, revealing that DG IGZO TFTs exhibited good performance for reliability analysis. The reliability and degradation mechanism of the DG IGZO TFT was systematically investigated under bias stress at room temperature and elevated temperatures of 350, 400, and 450 K by the comprehensive electrical characterization. Results indicate that the defects of the dual gate insulators and the interfaces majorly influence the degradation under bias stresses, while the carrier scattering of the IGZO channel is the major degradation mechanism under elevated temperatures. These findings highlight the degradation mechanism of the DG IGZO TFT under bias stress and elevated temperatures from a novel viewpoint, which provides a utilizable reference to its application in circuits.