Investigation of NH3 Plasma Nitridation on Hysteresis-Free Gate-All-Around Stacked Poly-Si Nanosheet Channel FeFETs

In this study, hysteresis-free double-layer gate-all-around stacked poly-Si nanosheet channel ferroelectric field-effect transistors (DL GAA NS FeFETs) and NH
3
plasma nitridation have been investigated and discussed. The NH
3
plasma nitridation at both metal/oxide interfaces can effectively improve the Hf
x
Zr
1–x
O
2
(HZO) ferroelectricity and quality by reducing the amount of oxygen vacancy (V
o
) as well as enhance the SiON interfacial layer quality by passivating the bulk defects. Therefore, devices can show the most excellent electrical characteristics: 1) extremely low subthreshold swing (S.S.) ~ 45.77 mV/decade, 2) high ON/OFF current ratio (I
ON
/I
OFF
) > 5 × 10
⁷
, and 3) high effective breakdown voltage (V
EBD
) ~ 6.7 V at V
D
= 0.1 V. These devices are very promising candidates for the low-power-consumption monolithic 3-D integrated circuit (IC) applications.