Investigation of Channel Parasitic Effect of CMOS Transistor for High Responsivity 2.58 THz Detector Array With Patch Antennas in Chip

This article is mainly to investigate the responsivity (
R_v
) and noise equivalent power (NEP) performance of a 2.58 THz complementary metal-oxide-semiconductor (CMOS) detector under transistor parasitic capacitance effect between the gate-source and the gate-drain with different gate-source distances. The capacitance effect of the transistor was incorporated into existing response models to explore the enhanced response. A 4×8 terahertz (THz) detector array is designed and fabricated using 55-nm CMOS technology based on the asymmetric distance between the gate-source and gate-drain. Each detector comprised a high-efficiency on-chip single-ended patch antenna and a source-driven NMOS field-effect transistor. At 195-Hz modulation frequency, the enhanced
R_v
of the designed THz imaging chip measured using lock-in techniques achieved the best
R_v
of 573.5 V/W, and the minimum NEP of the detector unit was 95.9 pW/Hz
^1/2
for the 2.58 THz at room temperature. Mechanical scanning transmission imaging of the leaf was carried out for verification with good quality.