A Comparative Study on the Effect of Dielectric Gate Materials on Analog and RF Performance of a Symmetrical Underlap DG Si/SiGe-based MOS-HEMT Device

This paper aims to elucidate a comparative and analytical study based on the analog characteristics of a Symmetrical Underlap DG Si/SiGe-based MOS-HEMT with varying effective k-values of the gate dielectric materials. This study examines the influence of different dielectric gate materials on the Analog Figures of Merit (FOMs) and RF performance such as drain current (I
d
), transconductance (g
m
), transconductance generation factor (g
m
/I
d
), output resistance (R
o
), the intrinsic gain of the device (g
m
R
o
), and Cut-off frequency (F
T
). The Device with HfO
2
as gate oxide resulted in faster-switching transients, higher transconductance, elevated efficiency, improved gain performance, and better cut-off frequency at low voltages. Further, this device showed an increase of approximately 20% and 10% increase in drain current with respect to the device with SiO
2
and the device with both materials as gate oxide respectively.