Influence of the Gate Height Engineering on the Intrinsic Parameters of UDG-MOSFETs With Nonquasi Static Effect

This paper presents the results of a systematic theoretical investigation on the impact of gate height on the analog and radio-frequency (RF) performances of underlap-FinFET devices. The conventional underlap-FinFETs offer lower on current (I
_on
) and higher distributed channel resistance (R
_ch
). This paper shows that a higher gate height improves both I
_on
and R
_ch
due to higher gate side-wall fringing fields. In this paper, the various figure of merits (FOMs) for analog applications of the underlap-FinFETs such as drain current (Ids), transconductance (g
_m
), transconductance generation factor (g
_m
/I
_ds
), output resistance (R
_o
), and intrinsic gain (g
_m
R
_o
) are systematically analyzed for different values of gate height and reported. The RF FOMs studied include intrinsic capacitances (C
_gs
, C
_gd
) and resistances (R
_gs
, R
_gd
), transport delay (τ
_m
), cutoff frequency (f
_T
), and the transit frequency of maximum available power gain (f
_MAX
). This paper clearly demonstrates that the gate height is a critical technology parameter in improving the analog performance of underlap-FinFETs.