$\hbox {MoS}_{2}$ Dual-Gate MOSFET With Atomic-Layer-Deposited $\hbox {Al}_{2}\hbox {O}_{3}$

We demonstrate atomic-layer-deposited (ALD) high-k dielectric integration on 2-D layer-structured molybdenum disulfide (MoS₂) crystals and MoS₂ dual-gate n-channel MOSFETs with ALD Al₂O₃ as the gate dielectric. Our C- V study of MOSFET structures shows good interface between 2-D MoS₂ crystal and ALD Al₂O₃. Maximum drain currents using back gates and top gates are measured to be 7.07 and 6.42 mA/mm, respectively, at V_ds = 2 V with a channel width of 3 μm, a channel length of 9 μm, and a top-gate length of 3 μm. We achieve the highest field-effect mobility of electrons using back-gate control to be 517 cm²/V·s. The highest current on/off ratio is over 10⁸.