On-wafer Measurements of Responsivity of FET-based subTHz Detectors

This article describes a novel approach to measure responsivity of a FET-based sub-THz detector using on-wafer probes to directly feed a bare antenna-less detecting device. Thus, the approach eliminates the need to know beforehand the detector's effective aperture, which can be a source of large variation between responsivity measurements of various FET-based detectors often cited in the literature. It seems that the presented method can be useful at making direct comparisons between responsivity of various devices (e.g. MOSFETs, HEMTs etc.). As a demonstration, the sub-THz responsivity of FET devices fabricated using three different processes has been measured in the WR-3 band and compared.