Reconfigurable ferroelectric hafnium oxide FeFET fabricated in 28 nm CMOS technology for mmWave applications

In this work we introduce reconfigurable multifinger ferroelectric field effect transistors (FeFETs) which were fabricated using 28 nm CMOS technology. By switching the threshold voltage, the FeFETs can be utilized as reconfigurable devices for RF circuits, functioning at V
GS
= 0, thereby reducing energy losses during operation. The devices were realized in the common-source configuration and demonstrated a memory window of more than 1 V along with an exceptional performance at mmWave frequencies. For a 32×1µm device with 80 nm gate length, the transit frequency (f
T
) and maximum oscillation frequency (f
MAX
) were calculated to be 113 GHz and 230 GHz, respectively. These f
T
/f
MAX
values are the highest among reconfigurable RF FeFETs.