Effects of Forming Gas Annealing and Channel Dimensions on the Electrical Characteristics of FeFETs and CMOS Inverter

Abstract

In this study, ferroelectric FETs (FeFETs) and CMOS inverters are fabricated and analyzed, exhibiting 13% of 593 devices with sub-60 mV subthreshold swing (SS) at room temperature. Forming gas annealing (FGA) is found to not only enhance ferroelectricity but also significantly improve FeFET electrostatics. The experimental results indicate that FeFET with a narrow width shows weaker ferroelectric properties, and SS of sub-60 mV/dec with ID change less than two orders of magnitude. However, FeFET with a broad channel width reveals stronger ferroelectric properties, and SS of sub-60 mV/dec is over 2 orders of magnitude of Id. Finally, typical voltage transfer characteristics (VTCs) of a FeFET CMOS inverter with double sweeps at various VD from 0.6 to 2 V are demonstrated. The results show that hysteresis in a FeFET CMOS inverter could have both clockwise (CW) and counter-clockwise (CCW) loops.

Keywords

• FeFET
• forming gas annealing (FGA)
• steep slop
• HfZrO₂
• ferroelectric