3D Integration of Vertical-Stacking of MoS₂ and Si CMOS Featuring Embedded 2T1R Configuration Demonstrated on Full Wafers

Abstract

For the first time, a 3D stacking of MoS <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> and Si CMOS integrated with embedded RRAM is proposed and fabricated, and CMOS inverter comprised of MoS <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> nFET and Si pFET is demonstrated. Vertically stacked multiple MoS <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> channels are required for the performance matching. Resistive switching (RS) of a Ti/MoS <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> /p <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">+</sup> -Si structure showing high ON/OFF ratio of 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">6</sup> is demonstrated firstly by highly Si-compatible process. Surface modification is the key to formation of uniform and smooth stacked MoS <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> multiple channels and to enhanced resistive switching endurance. This scheme can be applied to CMOS-based bipolar RRAM 1T1R or 2T1R without increasing the cell size. Our work offers a new pathway with high feasibility of integrated 2D materials and Si FETs into CMOS to enabling 3D embedded logics and memories for future computing systems.