Terahertz responsivity enhancement and low-frequency noise study in silicon CMOS detectors using a drain current bias

We report on the study of the enhancement of responsivity and properties of low-frequency noise in silicon 0.25 µm CMOS transistor-based detectors for terahertz radiation under applied dc source-to-drain current. We find that at signal modulation frequencies above 50 kHz the signal-to-noise ratio becomes independent from applied current, whereas the responsivity of detectors can be enhanced up to three times. We present quantitative results of noise measurements in the frequency range from 600 Hz to 1 MHz and currents up to the saturation current.