Ultrathin MoS₂-Channel FeFET Memory With Enhanced Ferroelectricity in HfZrO₂ and Body-Potential Control

Abstract

We have experimentally demonstrated memory operation of a HfO2-based ferroelectric FET (FeFET) with an ultrathin MoS2 channel and bottom-gate structure. ZrO2 seed layer enhances ferroelectricity in HfZrO2 by post deposition anneal process. Surface passivation of a MoS2 layer reduces the instability of the transistor characteristics. An additional top gate effectively controls the body potential instead of floating body. Thereby, FeFET memory operation was realized with enhanced ferroelectricity and body-potential control. By using pulse write operation, the ultrathin MoS2 channel FeFET showed the memory window of 0.22V, the retention time >5000 seconds, and the endurance cycles were $> 10^{6}$ times. This work highlights the applicability of the device for high-density memory such as 3D FeFET.

Keywords

• MoS₂
• FeFET
• ferroelectric HfO₂