A study on scaling behavior of responsivity and low frequency noise of Si MOSFET-based terahertz detectors

We study scaling behaviour of terahertz responsivity and low-frequency noise of silicon MOSFET-based detectors. A set of 550-GHz resonant patch-antenna-coupled transistors with different channel widths varying from 320 nm to 1920 nm have been fabricated and investigated in temperature range from 77 K to 360 K. We find that the best sensitivities are achieved for narrowest devices without applied bias. When biased, all samples exhibit strong contributions random-telegraph switching noise. Characteristic time constants of the generation and recombination processes in investigated transistors vary from millisecond to microseconds.