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

• Published in: IEEE electron device letters Vol. 39; no. 9; pp. 1413 - 1416
• Main Authors: Ikamas, Kestutis, Cibiraite, Dovile, Lisauskas, Alvydas, Bauer, Maris, Krozer, Viktor, Roskos, Hartmut G.
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.09.2018; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Antenna design; Broadband; broadband antenna; Broadband antennas; CMOS; Detectors; FET device modeling; Field effect transistors; field-effect transistor; Frequency response; Log spiral antennas; Logic gates; Metals; Narrowband; Optical noise; rectification; Semiconductor devices; Silicon; Spiral antennas; submillimeter-wave detector; terahertz detector; THz power detector; Transistors
• ISSN: 0741-3106; 1558-0563
• DOI: 10.1109/LED.2018.2859300

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 physics-based 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/<inline-formula> <tex-math notation="LaTeX">\sqrt {\textsf {Hz}} </tex-math> </inline-formula> at 0.6 THz and 70 pW/<inline-formula> <tex-math notation="LaTeX">\sqrt {\textsf {Hz}} </tex-math> </inline-formula> 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.