Terahertz (THz) commonly refers to a region of the electromagnetic spectrum with frequencies ranging between 0.1 to 10 THz (wavelengths of 3 mm to 30 μm). The technology available for detection and generation in this spectral region has been less developed than in the adjoining infrared and visible domains. For the astronomy community, THz observation provides information related to various phenomena including, for example, the study of cosmic microwave background radiation (CMBR), emission from proto-planetary disks, and planetary atmospheric remote sensing. Many molecules have emission and absorption spectral features in the THz regime whose observation provides the ability to extract information on chemical composition, abundances, and environmental conditions.
Current detector technology utilized for THz astrophysics typically utilizes bolometers or kinetic inductance devices (KIDs) that must be cooled and are available in limited array size. Detectors that could be operated in a fashion similar to that available in the visible, both in format and array size, would be very welcome. Bow-tie antenna-coupled silicon metal oxide semiconductor field effect transistors (Si-MOSFETs) have shown promise in detecting THz radiation for terrestrial applications. They have been fabricated in array formats and scaling to formats of interest to astronomers is straightforward. However, the characterization of such devices is insufficient to determine if they could be operated and optimized to be useful in some astronomical applications.
This dissertation presents the characterization and analysis of such bow-tie antenna-coupled Si-MOSFETs designed for detection near 0.2 THz. Design parameters for the Si-MOSFETs, such as antenna size and source region, were varied in devices manufactured using MOSIS foundry access. These devices were extensively tested in this work to determine the fabrication parameters providing optimal performance. An exploration of the detection mechanism for the devices and its consistency with the characterization results will also be presented. This characterization will include a study of the nonlinearity of these devices with incident power. The detector sensitivity and noise requirements for a small-scale space mission will be discussed and compared to the devices tested. Finally, a discussion on potential future development for these detectors will be provided.
Library of Congress Subject Headings
Submillimeter waves; Metal oxide semiconductor field-effect transistors--Materials; Detectors--Design and construction
Astrophysical Sciences and Technology (Ph.D.)
Department, Program, or Center
School of Physics and Astronomy (COS)
Seery, Katherine E., "Characterization of Si-MOSFETs for Terahertz Detection: Development for a Potential Future Astrophysical Sensor Technology" (2021). Thesis. Rochester Institute of Technology. Accessed from
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