Record-High Performance Trantenna Based On Asymmetric Nano-Ring Fet For Polarization-Independent Large-Scale/Real-Time Thz Imaging

Abstract

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 $( d_{S})$ scaling from 30 to 0.38 mm, 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. Highlyscalable and feeding line-free monolithic trantenna enables a high-performance THz detector with responsivity of 8.8 kV/W and NEP of 3.36 pW/Hz0.5 at the target frequency.