Active solid-state devices (e.g. – transistors – solid-state diode – Heterojunction device – Field effect transistor
Reexamination Certificate
2008-09-02
2008-09-02
Luu, Chuong A. (Department: 2892)
Active solid-state devices (e.g., transistors, solid-state diode
Heterojunction device
Field effect transistor
C257S019000, C257S184000, C257S187000
Reexamination Certificate
active
11290090
ABSTRACT:
A direct detector for terahertz radiation comprises a grating-gated field-effect transistor with one or more quantum wells that provide a two-dimensional electron gas in the channel region. The grating gate can be a split-grating gate having at least one finger that can be individually biased. Biasing an individual finger of the split-grating gate to near pinch-off greatly increases the detector's resonant response magnitude over prior QW FET detectors while maintaining frequency selectivity. The split-grating-gated QW FET shows a tunable resonant plasmon response to FIR radiation that makes possible an electrically sweepable spectrometer-on-a-chip with no moving mechanical optical parts. Further, the narrow spectral response and signal-to-noise are adequate for use of the split-grating-gated QW FET in a passive, multispectral terahertz imaging system. The detector can be operated in a photoconductive or a photovoltaic mode. Other embodiments include uniform front and back gates to independently vary the carrier densities in the channel region, a thinned substrate to increase bolometric responsivity, and a resistive shunt to connect the fingers of the grating gate in parallel and provide a uniform gate-channel voltage along the length of the channel to increase the responsivity and improve the spectral resolution.
REFERENCES:
patent: 4821093 (1989-04-01), Iafrate et al.
Wanke, Michael, Terahertz Radiation Mixer, Apr. 25, 2005.
X. G. Peralta,Terahertz photoconductivity and plasmon modes in double-quantum-well field-effect transistors, Applied Physics Letter, vol. 81, No. 9, Aug. 26, 2002, 1627-1629.
Mark Lee,Millimeter wave mixing using plasmon and bolometric response in a double-quantum-well field-effect transistor, Applied Physics Letters, vol. 86, 033501-1-033501-3 (2005).
E. A. Shaner, “Single-quantum-well grating-grated terahertz plasmon detectors,” Applied Physics Letters, vol. 87, 193507-1-193507-3.
Taiichi Otsuji, “Terahertz plasma wave resonance of two-dimensional electrons in InGaP/InGaAs/GaAs high-electron-mobility transistors,” Applied Physics Letters, vol. 85, No. 11, Sep. 13, 2004, 2119-2121.
W. Knap,Resonant detection of subterahertz and terahertz radiation by plasma waves in submicron field-effect transistors, Applied Physics Leters, vol. 81, No. 24, Dec. 9, 2002, 4637-4639.
Niu Jin,High Sensitivity Si-Based Backward Diodes for Zero-Based Square-Law Detection and the Effect of post-Growth Annealing on Performance, IEEE Electron Device Letters, vol. 26, No. 8, Aug. 2005, 575-578.
U.S. Appl. No. 11/113,635, filed Apr. 25, 2005, Michael C. Wanke, et al.
Allen S. James
Lee Mark
Shaner Eric A.
Wanke Michael C.
Bieg Kevin W.
Luu Chuong A.
Sandia Corporation
LandOfFree
Direct detector for terahertz radiation does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Direct detector for terahertz radiation, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Direct detector for terahertz radiation will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3916569