Wide-range and area-selective threshold voltage tunability in ultrathin indium oxide transistors
Robert Tseng, Sung-Tsun Wang, Tanveer Ahmed, Yi-Yu Pan, Shih-Chieh Chen, Che‐Chi Shih, Wu‐Wei Tsai, Hai-Ching Chen, Chi‐Chung Kei, Tsung-Te Chou, Wen‐Ching Hung, Jyh-Chen Chen, Yi-Hou Kuo, Chun‐Liang Lin, Wei-Yen Woon, Szuya Sandy Liao, Der‐Hsien Lien
Abstract
Abstract The scaling of transistors with thinner channel thicknesses has led to a surge in research on two-dimensional (2D) and quasi-2D semiconductors. However, modulating the threshold voltage ( V T ) in ultrathin transistors is challenging, as traditional doping methods are not readily applicable. In this work, we introduce a optical-thermal method, combining ultraviolet (UV) illumination and oxygen annealing, to achieve broad-range V T tunability in ultrathin In 2 O 3 . This method can achieve both positive and negative V T tuning and is reversible. The modulation of sheet carrier density, which corresponds to V T shift, is comparable to that obtained using other doping and capacitive charging techniques in other ultrathin transistors, including 2D semiconductors. With the controllability of V T , we successfully demonstrate the realization of depletion-load inverter and multi-state logic devices, as well as wafer-scale V T modulation via an automated laser system, showcasing its potential for low-power circuit design and non-von Neumann computing applications.