Terahertz Imaging Circuits in CMOS

An 820-GHz 8×8 imaging array of diode-connected NMOS transistor detectors, and 5-, and 10-THz fundamental Schottky diode detectors are demonstrated in a 130-nm bulk CMOS process. Measured mean optical responsivity (Rv) of 2.6kV/W and mean optical NEP of 36pW/Hz1/2 at a modulation frequency of 1MHz are achieved for the 820-GHz imaging array. The NEP is more than 2.5X lower than that of the previously reported NMOS terahertz imaging arrays. The fundamental electronic detection of Far-Infrared radiation up to 9.74THz is also reported. A peak Rv of 383 at 4.92THz and a peak Rv of 14V/W at 9.74THz have been measured using a free electron laser. The Rv at 9.74THz is 14X of that for the previously reported highest frequency electronic detection. The shot noise limited NEP at 4.92 and 9.74THz is ∼0.43 and ∼2nW/VHz, respectively.