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 mu 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 similar to 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 pW/Hz(0.5) at the target frequency.