Correlation of Gate Capacitance with Drive Current and Transconductance in Negative Capacitance Ge PFETs

Correlation of gate capacitance CG with drive current IDS and transconductance G
_m
in negative capacitance (NC) Ge pFETs is first investigated. Hysteresis-free NC Ge pFETs integrated with 4.5-nm HZO achieving the improved I
_DS
and G
_m
over the control devices are fabricated. A peak in the C
_G
versus gate voltage curve is demonstrated in the NC Ge pFET, indicating the NC effect induced by HZO film. It is observed that I
_DS
and G
_m
of the NC transistors are enhanced as the C
_G
peak gets increased. This is attributed to the fact that, as the device operates in the NC region, both C
_G
and internal gate voltage amplification are proportional to CFE/(CFE + CMOS), where C
_FE
and CMOS are the NC of HZO and the MOS capacitance of the device, respectively.