RF performance of 28nm PolySiON and HKMG CMOS devices

The impact of scaling in advanced RF/MS-CMOS has been extensively discussed but there has not been a publication that compares the RF characteristics of 28nm high-K metal gate HKMG and PolySiON technologies fabricated in the same facility. In this work, we show that HKMG improves transistor f
_T
and increases varactor tunning range. However, it can actually decrease f
_max
. We examine how process features made to optimize cost and digital performance impact the RF performance. Process features which improve DC current and gm, including HKMG also give higher f
_T
. However, f
_max
is sensitive to gate resistance and PolySiON has an advantage here.