Responsivity enhancement techniques for CMOS source‐driven terahertz detectors

Abstract

The size and asymmetry effects of MOSFET detectors operating in a source‐driven configuration on responsivity are discussed in this paper. Seven MOSFET detectors with different sizes and structures are fabricated in a standard 55 nm CMOS technology. At 2.58 THz, the measurement results show that for the symmetric device, the minimum size MOSFET can achieve a higher responsivity, and for the asymmetric device, when the ratio of the source channel width to the drain channel width reaches 4:1 or higher, the asymmetric detector can achieve a higher responsivity than the detector based on the minimum size device available in the process. The best responsivity of the 2.03 kV/W is achieved by the asymmetry structure MOSFET detector with the ratio of the source channel width to the drain channel width reaching 4:1.

Review on Physics and Modelling of THz Radiation Detection Using Field-effect Transistors

“…Kopyt et al [64] used the transmission line method to create a model of the MOSFET's channel to study the behaviour of the detector under sub-THz radiation delivered through the gate and source pads. By representing the device with an electric equivalent circuit (as in the TCL model), the device could be simulated using a standard circuit simulator ( SPICE model) at frequencies significantly higher than the device cut-off frequency, as in the work of Guttin et al [25,65,66]. Fig.…”

A Novel Terahertz Detector Based on Asymmetrical FET Array in 55-nm Standard CMOS Process

“…Antenna-coupled MOSFET detectors show poor performance at high frequencies, since the return loss between the antenna and the detector will increase as frequency increases, due to the existence of antenna. In order to solve the above problems, the impedance matching structures have been used to reduce the return loss [ 18 , 19 ], hence the new antenna structures [ 20 , 21 ] or asymmetric MOSFET structures [ 22 , 23 ] have been used to improve the performance of the THz detector. Although these approaches can solve some problems, the impedance matching is very difficult to realize in high-frequency, and the new structure antennas are likely to further increase the detector area.…”