THz Detection Using p+/n-Well Diodes Fabricated in 45-nm CMOS

Electronic-detection up to ~0.9 THz using p±/n-well junction diodes in a 45-nm bulk CMOS process is demonstrated. Because the 1/f noise corner frequency is ~1 kHz instead of ~10 MHz common to Schottky and diode-connected nMOS transistor detectors, despite lower responsivity, detectors using a p
⁺
/n-well diode with an optimized transit time achieve competitive noise equivalent power (NEP) while exhibiting smaller variations. The junction diode has a measured zero-bias cutoff frequency ( fT) of ~1.8 THz. The direct-antenna matched structure can reach a peak optical responsivity (Rv) of 558 V/W at 0.781 THz with a minimum optical NEP of 56 pW/Hz
^0.5
at a modulation frequency of 100 kHz.