High-Responsivity 3.2 THz Detector Design and TCAD Modeling in 28 nm CMOS Technology

THz detectors based on CMOS technology have garnered widespread attention due to their potential in building compact, low-power, and scalable THz sensing and imaging systems. This paper proposes a 3.2 THz plasmonic wave detector fabricated in a standard 28 nm CMOS process, featuring an integrated on-chip antenna and NMOS transistor design. A response model was established, in which the NMOS input impedance at 3.2 THz extracted from the calibrated TCAD model was incorporated to evaluate the detector performance. At a modulation frequency of 2 kHz, the highest Rv of 830.1 V/W and the lowest NEP of 63.1 pW/Hz1/2 were obtained. The predicted results show good agreement with the experimental measurements, confirming the effectiveness of the TCAD-assisted response modeling approach. Furthermore, demonstration experiments such as concealed object detection and high-resolution biological sample imaging further confirm the practical value of this CMOS detector in compact THz sensing and imaging systems.