Broadband Terahertz Power Detectors Based on 90-nm Silicon CMOS Transistors With Flat Responsivity Up to 2.2 THz

Abstract

We present broadband high sensitivity terahertz (THz) detectors based on 90 nm CMOS technology with the state-of-the-art performance. The devices are based on bow-tie and log-spiral antenna-coupled field-effect transistors (FETs) for the detection of free-space THz radiation (TeraFETs). We report on optimized performance, which was achieved by employing an in-house developed physicsbased model during detector design and thorough device characterization under THz illumination. The implemented detector with bow-tie antenna design exhibits a nearly flat frequency response characteristic up to 2.2 THz with an optical responsivity of 45 mA/W (or 220 V/W). We have determined a minimum optical noise-equivalent power as low as 48 pW/ √ Hz at 0.6 THz and 70 pW/ √ Hz at 1.5 THz. The results obtained at 1.5 THz are better than the best narrowband TeraFETs reported in the literature at this frequency and only up to a factor of four inferior to the best narrowband devices at 0.6 THz.

Plasmonic Helicity‐Driven Detector of Terahertz Radiation

“…TeraFET was experimentally demonstrated. [19] This result dramatically simplifies separating intrinsic frequency dependence of the detector. 3) A phase-sensitive detection with extremely high sensitivity was reported for detector operating in the homodyne regime and possibility to use TeraFET as spectrometer and/or interferometer was demonstarted.…”

“…Very recently, there appeared an opportunity for a further revolutionary breakthrough in this direction which is based on experimental results obtained this year by different groups: A resonant tunable response with clearly distinguishable contributions of several plasmonic harmonics was obtained in a graphene TeraFET A possibility to integrate broadband THz antennas with a TeraFET was experimentally demonstrated . This result dramatically simplifies separating intrinsic frequency dependence of the detector. A phase‐sensitive detection with extremely high sensitivity was reported for detector operating in the homodyne regime and possibility to use TeraFET as spectrometer and/or interferometer was demonstarted …”

“…They also might have own frequency dependence determined by antenna's properties. However, for recently implemented broadband antennas this dependence can be neglected within the narrow resonant width and, therefore, antennas can not mask the intrinsic response of the TeraFET. The latter has a sharp resonant frequency dependence and, therefore, can be easily distinguished from the smooth antennas‐induced contribution even for small U a and U b .…”

“…[1] and actively discussed subsequently as a THz emitter [2][3][4][5][6] and detector, [7][8][9][10][11][12][13][14][15][16][17][18] is now called the TeraFET. [19] The underlying physics responsible for superior performance of the TeraFET is a strong coupling of the THz radiation with nonlinear plasma waves in the cannel of field effect transistor (FET). [1,7] The TeraFET applications already being commercialized include sub-THz and THz detectors implemented in Si, [16,17] GaAs, [8][9][10][11][12][13][14][15] GaN, [8,18] graphene (see ref.…”

“…[22] ). The properly designed TeraFETs yield excellent detection of the THz radiation [19,[22][23][24][25][26][27][28] and have already achieved performance exceeding in some points that of the existing commercial detectors. The key advantages of such detectors are tunability, [7][8][9][10][11][12][13][14][15][16][17][18][19] a relatively low value of the noise equivalent power, [17,18] a potential to detect signals with very high modulation frequencies (up to hundreds of GHz), [29] and…”