Record-High Performance Trantenna based on Asymmetric Nano-Ring FET for Polarization-Independent Large-Scale/Real-Time THz Imaging

We demonstrate a record-high performance monolithic trantenna (transistor-antenna) using 65-nm CMOS foundry in the field of a plasmonic terahertz (THz) detector. By applying ultimate structural asymmetry between source and drain on a ring FET with source diameter
$(d_{\text{S}})$
scaling from 30 to
$0.37\mu \text{m}$
, we obtained 180 times more enhanced photoresponse
$(\Delta u)$
in on-chip THz measurement. Through free-space THz imaging experiments, the conductive drain region of ring FET itself showed a frequency sensitivity with resonance frequency at 0.12 THz in
$0.09\sim 0.2$
THz range and polarization-independent imaging results as an isotropic circular antenna. Highly-scalable and feeding line-free monolithic trantenna enables a high-performance THz detector with responsivity of 8.8 kV/
$W$
and NEP of
$3.36\text{pW}/\text{Hz}^{05}$
at the target frequency.