Characterization of the High Frequency Performance of 28-nm UTBB FDSOI MOSFETs as a Function of Backgate Bias

This paper describes for the first time the high frequency performance characterization of a production 28-nm ultra-thin-body-and-BOX (UTBB) fully-depleted (FD) SOI CMOS technology. The measured g_m, f_T, and maximum available gain (MAG) of fully-wired n-channel and p-channel MOSFETs are reported as a function of gate-source, drainsource, back-gate voltages and drain current density. It is shown that the back-gate bias can reduce the V_GS at which the peak g_m, peak f_T and peak MAG occur by up to 400 mV and can flatten the f_T-V_GS characteristics, as needed in highly linear amplifiers. The peak g_m/f_T values of 1.5mS/μm/298GHz and 0.93mS/μm/194GHz, for n-MOSFETs and p-MOSFETs respectively, match or exceed those of 28-nm LP bulk and 45-nm SOI MOSFETs with identical layout geometry and metal stack wiring.