Black Phosphorus Based Field Effect Transistors with Simultaneously Achieved Near Ideal Subthreshold Swing and High Hole Mobility at Room Temperature

• DOI: 10.1038/srep24920
• Publication Date: 2016-04-22T09:28:15Z
• Authors: Xinke Liu; Kah-Wee Ang; Wenjie Yu; Jiazhu He; Xuewei Feng; Qiang Liu; He Jiang; Dan Tang; Jiao Wen; Youming Lu; Wenjun Liu; Peijiang Cao; Shun Han; Jing Wu; Wenjun Liu; Xi Wang; Deliang Zhu; Zhubing He
• Keywords: 530; 01 natural sciences; 7. Clean energy; Article; 0104 chemical sciences

AbstractBlack phosphorus (BP) has emerged as a promising two-dimensional (2D) material for next generation transistor applications due to its superior carrier transport properties. Among other issues, achieving reduced subthreshold swing and enhanced hole mobility simultaneously remains a challenge which requires careful optimization of the BP/gate oxide interface. Here, we report the realization of high performance BP transistors integrated with HfO2 high-k gate dielectric using a low temperature CMOS process. The fabricated devices were shown to demonstrate a near ideal subthreshold swing (SS) of ~69 mV/dec and a room temperature hole mobility of exceeding >400 cm2/Vs. These figure-of-merits are benchmarked to be the best-of-its-kind, which outperform previously reported BP transistors realized on traditional SiO2 gate dielectric. X-ray photoelectron spectroscopy (XPS) analysis further reveals the evidence of a more chemically stable BP when formed on HfO2 high-k as opposed to SiO2, which gives rise to a better interface quality that accounts for the SS and hole mobility improvement. These results unveil the potential of black phosphorus as an emerging channel material for future nanoelectronic device applications.