Effect of Amorphous Si-Zn-Sn-O Passivation Layer on Si-In-Zn-O Thin Film Transistors

Abstract

Bi-layer thin film transistors (TFTs) have been fabricated with improved field effect mobility and stability. These TFTs feature a unique channel structure comprising a dielectric layer, an amorphous-Si-In-Zn-O (a-SIZO) layer, and an amorphous-Si-Zn-Sn-O (a-SZTO) layer. Total resistance of the channel and contact resistance between the electrode and channel were determined using transmission line method (TLM). Precisely deposited thin films via RF sputtering at room temperature, our TFTs, equipped with a bottom gate top contact and processed at 500 \(^{\circ }\)C, exhibited outstanding characteristics. They showcased high mobilities exceeding 30 cm\(^2\)V\(^{-1}\)s\(^{-1}\), a current on/off ratio of approximately 10\(^9\), and a subthreshold swing (SS) value below 0.45 V decade\(^{-1}\). Furthermore, these bi-layer TFTs demonstrated stability under negative and positive bias stress, indicating their potential for reliable performance across a range of applications and promising advancements in TFT technology.