Reconfigurable MoTe2 Field-Effect Transistors and its Application in Compact CMOS Circuits

Abstract

The outstanding physical and electrical properties of transition metal dichalcogenides (TMDs) as semiconductor materials demonstrate a promising platform for future electronic devices. Among all the TMDs, MoTe <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> , in which the bandgap is close to that of the silicon (Si), is a more favorable candidate than others to be applied in next-generation integrated circuits (ICs). However, the conventional physical or chemical doping method is complicated for fabricating the MoTe <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> logic ICs. The transistors with additional polarity gates (PGs) are defined as polarity-controllable transistors (PCTs). The PG can dynamically control the type of charge carriers (n- or p-type) in the source/drain by electrostatic doping without the need of any physical or chemical doping, and thus reconfigure the transistor between n-type and p-type. In our work, the ambipolar conduction property in MoTe <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> enables the fabrication of high-quality polarity-controllable MoTe <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> transistors (PCMTs) that are promising as building blocks to construct the MoTe <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> logic ICs. The on/off ratios of the PCMTs are above 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">7</sup> for both n-type and p-type. The highest field-effect mobility μ of p- and n-type MoTe <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> transistors are 38 and 42, respectively. The inverter (INV) based on the PCMTs has achieved a high gain of 37. Furthermore, the logic-gate cell library, which includes INV, negative- AND (NAND), negative- OR (NOR), exclusive- OR (XOR), and maJority (MAJ) is demonstrated using PCMTs. The above-mentioned desirable properties make PCMTs promising for future applications in 2-D-semiconductor-material-based logic ICs.