17 research outputs found
Silicon- and Graphene-based FETs for THz technology
[EN] This Thesis focuses on the study of the response to Terahertz (THz) electromagnetic
radiation of different silicon substrate-compatible FETs. Strained-Si MODFETs, state-of-
the-art FinFETs and graphene-FETs were studied.
The first part of this thesis is devoted to present the results of an experimental and
theoretical study of strained-Si MODFETs. These transistors are built by epitaxy of
relaxed-SiGe on a conventional Si wafer to permit the fabrication of a strained-Si electron
channel to obtain a high-mobility electron gas. Room temperature detection under
excitation of 0.15 and 0.3 THz as well as sensitivity to the polarization of incoming
radiations were demonstrated. A two-dimensional hydrodynamic-model was developed to
conduct TCAD simulations to understand and predict the response of the transistors. Both
experimental data and TCAD results were in good agreement demonstrating both the
potential of TCAD as a tool for the design of future new THz devices and the excellent
performance of strained-Si MODFETs as THz detectors (75 V/W and 0.06 nW/Hz0.5).
The second part of the Thesis reports on an experimental study on the THz behavior of
modern silicon FinFETs at room temperature. Silicon FinFETs were characterized in the
frequency range 0.14-0.44 THz. The results obtained in this study show the potential of
these devices as THz detectors in terms of their excellent Responsivity and NEP figures
(0.66 kV/W and 0.05 nW/Hz0.5).
Finally, a large part of the Thesis is devoted to the fabrication and characterization of
Graphene-based FETs. A novel transfer technique and an in-house-developed setup were
implemented in the Nanotechnology Clean Room of the USAL and described in detail in
this Thesis. The newly developed transfer technique enables to encapsulate a graphene
layer between two flakes of h-BN. Raman measurements confirmed the quality of the
fabricated graphene heterostructures and, thus, the excellent properties of encapsulated
graphene. The asymmetric dual grating gate graphene FET (ADGG-GFET) concept was
introduced as an efficient way to improve the graphene response to THz radiation. High
quality ADGG-GFETs were fabricated and characterized under THz radiation. DC
measurements confirmed the high quality of graphene heterostructures as it was shown
on Raman measurements. A clear THz detection was found for both 0.15 THz and 0.3
THz at 4K when the device was voltage biased either using the back or the top gate of the
G-FET. Room temperature THz detection was demonstrated at 0.3 THz using the
ADGG-GFET. The device shows a Responsivity and NEP around 2.2 mA/W and 0.04
nW/Hz0.5 respectively at respectively at 4K.
It was demonstrated the practical use of the studied devices for inspection of hidden
objects by using the in-house developed THz imaging system
Recommended from our members
Laboratory Directed Research and Development Program FY 2004 Annual Report
The Oak Ridge National Laboratory (ORNL) Laboratory Directed Research and Development (LDRD) Program reports its status to the U.S. Department of Energy (DOE) in March of each year. The program operates under the authority of DOE Order 413.2A, 'Laboratory Directed Research and Development' (January 8, 2001), which establishes DOE's requirements for the program while providing the Laboratory Director broad flexibility for program implementation. LDRD funds are obtained through a charge to all Laboratory programs. This report describes all ORNL LDRD research activities supported during FY 2004 and includes final reports for completed projects and shorter progress reports for projects that were active, but not completed, during this period. The FY 2004 ORNL LDRD Self-Assessment (ORNL/PPA-2005/2) provides financial data about the FY 2004 projects and an internal evaluation of the program's management process. ORNL is a DOE multiprogram science, technology, and energy laboratory with distinctive capabilities in materials science and engineering, neutron science and technology, energy production and end-use technologies, biological and environmental science, and scientific computing. With these capabilities ORNL conducts basic and applied research and development (R&D) to support DOE's overarching national security mission, which encompasses science, energy resources, environmental quality, and national nuclear security. As a national resource, the Laboratory also applies its capabilities and skills to the specific needs of other federal agencies and customers through the DOE Work For Others (WFO) program. Information about the Laboratory and its programs is available on the Internet at <http://www.ornl.gov/>. LDRD is a relatively small but vital DOE program that allows ORNL, as well as other multiprogram DOE laboratories, to select a limited number of R&D projects for the purpose of: (1) maintaining the scientific and technical vitality of the Laboratory; (2) enhancing the Laboratory's ability to address future DOE missions; (3) fostering creativity and stimulating exploration of forefront science and technology; (4) serving as a proving ground for new research; and (5) supporting high-risk, potentially high-value R&D. Through LDRD the Laboratory is able to improve its distinctive capabilities and enhance its ability to conduct cutting-edge R&D for its DOE and WFO sponsors. To meet the LDRD objectives and fulfill the particular needs of the Laboratory, ORNL has established a program with two components: the Director's R&D Fund and the Seed Money Fund. As outlined in Table 1, these two funds are complementary. The Director's R&D Fund develops new capabilities in support of the Laboratory initiatives, while the Seed Money Fund is open to all innovative ideas that have the potential for enhancing the Laboratory's core scientific and technical competencies. Provision for multiple routes of access to ORNL LDRD funds maximizes the likelihood that novel and seminal ideas with scientific and technological merit will be recognized and supported
Air Force Institute of Technology Research Report 2012
This report summarizes the research activities of the Air Force Institute of Technology’s Graduate School of Engineering and Management. It describes research interests and faculty expertise; lists student theses/dissertations; identifies research sponsors and contributions; and outlines the procedures for contacting the school. Included in the report are: faculty publications, conference presentations, consultations, and funded research projects. Research was conducted in the areas of Aeronautical and Astronautical Engineering, Electrical Engineering and Electro-Optics, Computer Engineering and Computer Science, Systems and Engineering Management, Operational Sciences, Mathematics, Statistics and Engineering Physics
Eleventh European Powder Diffraction Conference. Warsaw, September 19-22, 2008
Zeitschrift für Kristallographie. Supplement Volume 30 presents the complete Proceedings of all contributions to the XI European Powder Diffraction Conference in Warsaw 2008: Method Development and Application,Instrumental, Software Development, Materials. Supplement Series of Zeitschrift für Kristallographie publishes Proceedings and Abstracts of international conferences on the interdisciplinary field of crystallography
Sixteenth International Laser Radar Conference, part 2
Given here are extended abstracts of papers presented at the 16th International Laser Radar Conference, held in Cambridge, Massachusetts, July 20-24, 1992. Topics discussed include the Mt. Pinatubo volcanic dust laser observations, global change, ozone measurements, Earth mesospheric measurements, wind measurements, imaging, ranging, water vapor measurements, and laser devices and technology
Aeronautical engineering: A cumulative index to a continuing bibliography (supplement 248)
This publication is a cumulative index to the abstracts contained in Supplements 236 through 247 of Aeronautical Engineering: A Continuing Bibliography. The bibliographic series is compiled through the cooperative efforts of the American Institute of Aeronautics and Astronautics (AIAA) and the National Aeronautics and Space Administration (NASA). Seven indexes are included -- subject, personal author, corporate source, foreign technology, contract number, report number and accession number
Proceedings of the 2018 Canadian Society for Mechanical Engineering (CSME) International Congress
Published proceedings of the 2018 Canadian Society for Mechanical Engineering (CSME) International Congress, hosted by York University, 27-30 May 2018
Aeronautical Engineering: A continuing bibliography, supplement 96
This bibliography lists 448 reports, articles, and other documents introduced into the NASA scientific and technical information system in April 1978
Aeronautical engineering: A continuing bibliography with indexes (supplement 267)
This bibliography lists 661 reports, articles, and other documents introduced into the NASA scientific and technical information system in June, 1991. Subject coverage includes design, construction and testing of aircraft and aircraft engines; aircraft components, equipment and systems; ground support systems; theoretical and applied aspects of aerodynamics and general fluid dynamics; electrical engineering; aircraft control; remote sensing; computer sciences; nuclear physics; and social sciences