Demonstration of 2.58 THz detectors based on asymmetric channel transistors

Abstract

This letter presents several antenna-coupled 2.58 THz direct detectors based on 55 nm standard CMOS process. Each detector consists of a patch antenna and a metal-oxide-semiconductor field-effect-transistor (MOSFET) with an asymmetric channel. We demon-strated four detectors with THz wave coupling into the source with different width ratios of drain and source, and found that the responsivity is proportional to its asymmetric ratio. The detectors’ output signal is amplified with a low noise amplifier and extracted with a lock-in amplifier. The measured results showed that 2.58 THz detectors has a maximum responsivity (R_V) of 822.5 V/W, with a corresponding noise equivalent power (NEP) of 24.2 pW/Hz^0.5.