Abstract-Dual-frequency CMOS terahertz detector with silicon-based plasmonic antenna

Ruizhi Huang, Xiaoli Ji, Yiming Liao, Jingyu Peng, Ke Wang, Yue Xu, and Feng Yan

Fig. 1 (a) The schematic illustration of 3D stacked structure of dual-frequency CMOS THz detector and (b) Cross-section of the detector realized in standard CMOS technology.

https://www.osapublishing.org/oe/abstract.cfm?uri=oe-27-16-23250

Multi-frequency Terahertz (THz) detectors have shown great application potentials in THz imaging and sensing systems. For the first time to our knowledge, a novel dual-frequency THz detector with the stacked structure consisting of a silicon-based plasmonic antenna and a metal-based antenna in one compact unit is proposed and fabricated in standard CMOS technology. Compared with the metal antenna, the antenna based on heavy-doped poly-silicon materials enables the detector to excite localized surface plasmon resonance mode, making the effective absorption of the THz waves and thus resulting in the significant responsivity enhancement of the detector. The experimental results show a maximum voltage responsivity up to about 2000 V/W and 450 V/W, while the noise equivalence power is as low as 23 pW/Hz0.5and 110 pW/Hz0.5 for the silicon antenna and metal antenna at the frequency of 220 GHz and 650 GHz, respectively. The presented dual-frequency detector can be easily implemented in a small size in favor of high-density array integration.

© 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreement

Abstract-A 220- to 299-GHz CMOS Terahertz Detector

Zhao-yang Liu, Feng Qi, Ye-long Wang, Peng-xiang Liu, Wei-fan Li

https://link.springer.com/article/10.1007/s10762-019-00592-2

This paper proposes a terahertz (THz) detector in a 180-nm standard CMOS process. The detector consists of a square loop antenna and an NMOS transistor. The antenna has two feed ports. One is connected to the source of the transistor and the other is grounded to provide the source a dc ground. To improve the power transfer efficiency between the antenna and the transistor, impedance matching between them is needed. It is concluded that in order to increase the voltage responsivity of the detector, impedance matching should be achieved by changing the impedance of the antenna rather than by changing the impedance of the transistor. The parasitic capacitance and inductance of the gate power supply line will affect the antenna-transistor impedance matching. An open microstrip transmission line connected to the gate is designed to eliminate this influence. Measurement results show that the detector can detect THz radiation in the frequency range of 220 to 299 GHz. At 244 GHz, the detector achieves a best voltage responsivity of 2497 V/W and a noise equivalent power (NEP) of 357 pW/Hz1/2.