Transient negative capacitance and charge trapping in FDSOI MOSFETs with ferroelectric HfYOX

Artificial Sub-60 Millivolts/Decade Switching in a Metal–Insulator–Metal–Insulator–Semiconductor Transistor without a Ferroelectric Component

“…Different from the original proposal, alternative mechanisms for the observed steep slope switching have been proposed and the validity of a stabilizing negative capacitance (NC) region of FE materials has been challenged [11][12][13] . For example, some papers relate the observed steep switching to transient effects such as internal potential jumps 14,15 or differential voltage amplification caused by polarization switching of FE material [16][17][18][19][20][21][22] , instead of a quasi-static NC effect represented as the "S"-shaped curve in the polarization-electric field (P-E) relation of FE materials 1,23,24 .…”

“…Since then, sub-60 mV/decade operations have been reported in NC-FETs from various material systems and device structures. − However, the origin of the observed steep-slope switching is still under intense debate. Different from the original proposal, alternative mechanisms for the observed steep slope switching have been proposed, and the validity of a stabilizing negative capacitance (NC) region of FE materials has been challenged. − For example, some papers relate the observed steep switching to transient effects such as internal potential jumps , or differential voltage amplification caused by polarization switching of the FE material, − instead of a quasi-static NC effect represented as the “S”-shaped curve in the polarization–electric field ( P – E ) relation of FE materials. ,, Other explanations include domain nucleation and growth in multidomain FE materials. ,, Yet due to the complexity of both the ferroelectric physics and the experimental systems, there has not been a single consolidated theory that can convincingly explain all the experimental findings. Therefore, a model system exhibiting similar device characteristics yet with simplified physics is highly sought after.…”