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

Electronic-detection up to similar 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 similar to 1 kHz instead of similar to 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 (f(T)) of similar to 1.8 THz. The direct-antenna matched structure can reach a peak optical responsivity (R-v) 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.