Design and Demonstration of Antenna-Coupled Schottky Diodes in a Foundry Complementary Metal-Oxide Semiconductor Technology for Electronic Detection of Far-Infrared Radiation
Electronic detection of far-infrared (FIR) radiation up to 9.74 THz is reported in a foundry complementary metal-oxide semiconductor (CMOS) technology. The detectors were fabricated with Schottky-barrier diodes (SBDs) formed in 130-nm CMOS without any process modifications. Direct-antenna matched detectors achieve a measured peak optical responsivity (R V ) of 383 and 25 V/W at 4.92 and 9.74 THz, respectively, near the 5 and 10 THz fundamental frequency of the antennas. A significantly improved R V at 9.74 THz (25× compared to the MOSFET detectors and ~2× compared to the SBD) ensures negligible impact on the system noise-equivalent power (NEP) due to the input-referred noise of the amplifier following the detector. This work also demonstrated that by incorporating the effects of plasma resonance, transit time, and FIR absorption behavior of SiO 2 , as well as the 3D electromagnetic simulations into the SBD model, good agreement between the measurements and simulations can be attained. The detector designed for a 10-THz operation achieves an optical NEP of 1.1 nW/vHz at 9.74 THz in the shot-noise limit, which is comparable to that of commercially available pyro-detectors that are 50 000× larger. © 2019 Author(s).