Performance Enhancement of Oxide-Based Source-Gated Transistors via Structural and Contact Engineering

Abstract

A 2T1C driving transistor (TFT), which is commonly used in OLED pixels, must supply a constant current to the OLED. However, as the operating time of the device increases, the drain voltage (Vd) may vary, leading to corresponding variations in the drain current. To ensure a stable current supply, the transistor must have a low saturation voltage and strong current saturation characteristics. In this study, a top-gate SGT structure that exhibits these characteristics was fabricated and its electrical properties were characterized. Furthermore, to address the relatively low drain current associated with SGTs due to the source barrier, process and structural optimizations were implemented by increasing the source– gate overlap and modifying the drain electrode metal. Consequently, a linear increase in drain current was observed as the source–gate overlap increased, and replacing the drain electrode from Pt to Au improved the drain current by more than one order of magnitude.