RF behavior of undoped channel ultra-thin body with ultra-thin BOX MOSFETs

RF performance of ultra-thin body with ultra-thin buried oxide (BOX), so-called UTBB, MOSFETs with gate length down to 30 nm is presented. Current gain cut-off frequency f_T and maximum oscillation frequency f_max of 160 GHz and 143 GHz, respectively, are demonstrated. Based on an accurate extraction of the small-signal equivalent circuit of UTBB MOSFET over a wide frequency range, it is revealed that ground plane (GP) implementation (i.e. highly-doped region underneath the BOX)does not increase the high frequency parasitic capacitances, and thus does not degrade the RF performance of UTBB devices.