Narrow-Width Effect on High-Frequency Performance and RF Noise of Sub-40-nm Multifinger nMOSFETs and pMOSFETs

The impact of narrow-width effects on high-frequency performance like
fT
,
f
_MAX
, and RF noise parameters, such as
NF
_min
and
Rn
, in sub-40-nm multifinger CMOS devices is investigated in this paper. Narrow-oxide-diffusion (OD) MOSFET with smaller finger width and larger finger number can achieve lower
Rg
and higher
f
_MAX
. However, these narrow-OD devices suffer
fT
degradation and higher
NF
_min
, even with the advantage of lower
Rg
. The mechanisms responsible for the tradeoff between different parameters will be presented to provide an important guideline of multifinger MOSFET layout for RF circuit design using nanoscale CMOS technology.