RF Performance of a Fully Integrated 3D Sequential Technology

RF performance of a fully integrated CMOS 3D Sequential Integration (3DSI) is, for the first time, deeply investigated. We highlight that Top Tier PMOS processed at 630°C can feature good RF Figure-Of-Merits (FOM) with F
_t
=55GHz and F
_max
=80GHz at L=30nm and V
_DD
=-1V. Moreover, it is proved that these RF features for Top Tier transistors are achieved without altering those of Bottom Tier devices. Finally, we identify, by means of advanced characterization and modeling, mobility and gate resistance as the key electrical factors affecting our RF FOM. Optimizing these two parameters throughout a novel low temperature process (T<; 530°C), we achieve a record performance for a low temperature PMOS, of F
_t
=102GHz and F
_max
=170GHz.