Broadband terahertz imaging with highly sensitive silicon CMOS detectors

CEA-LETI, MINATEC Campus, 38054 Grenoble, France.
Optics Express (Impact Factor: 3.49). 04/2011; 19(8):7827-32. DOI: 10.1364/OE.19.007827
Source: PubMed


This paper investigates terahertz detectors fabricated in a low-cost 130 nm silicon CMOS technology. We show that the detectors consisting of a nMOS field effect transistor as rectifying element and an integrated bow-tie coupling antenna achieve a record responsivity above 5 kV/W and a noise equivalent power below 10 pW/Hz(0.5) in the important atmospheric window around 300 GHz and at room temperature. We demonstrate furthermore that the same detectors are efficient for imaging in a very wide frequency range from ~0.27 THz up to 1.05 THz. These results pave the way towards high sensitivity focal plane arrays in silicon for terahertz imaging.

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Available from: Laurent Dussopt, Sep 02, 2015
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    • "mW = 842 V/W at Z a = 50 (325 times) than those of sample B (75 times) from the result of the detector without antenna as shown in inset from Ref. [7], even if sample B and C have same criterion of Z gs < 50 as expected in Fig. 3. The lowest noiseequivalent-power (NEP) in sample C (inset) has been obtained as 18 pW/ √ Hz at V GS -V T = 0.25 V commonly based on the channel thermal noise (N = (4kTR ch ) 0.5 ), which is comparable with the reported lowest NEP values for antenna-coupled plasmonic Si-based THz detectors [3], [19], owing to the relatively low channel resistance (R ch ) from large micron-scale width for low-impedance MOSFET design. It can be noted that these enhancement trends of R v and NEP in sample C with thinner T ox mainly originate from increase of the plasmonic channel electron density modulation by T ox scaling. "
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    ABSTRACT: We demonstrate the performance enhancement of field-effect transistor (FET)-based plasmonic terahertz (THz) detector with monolithic integrated antenna in low-impedance regime and report the experimental results of Si MOSFET impedance in THz regime using 0.2-THz measurement system. By designing FET with low-impedance ranges (<1 k) and integrating antennas with impedances of 50 and 100 , we found that our low-impedance MOSFETs have the input impedance criterion of 50 at 0.2 THz and the MOSFETs with thinner gate oxide show the highly enhanced plasmonic photoresponses at 50-antenna by 325 times from the result of the detector without antenna.
    Full-text · Article · Mar 2015 · IEEE Electron Device Letters
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    • "Terahertz plasmonic field effect transistor (FET) detectors [1] implemented in Si [2] [3] [4] [5], GaAs/InGaAs [6] [7] [8], GaN, [9] and graphene technologies [10] demonstrated responsivities up to 5.8 kV/ W [11] and up to 90 kV/W with on-chip amplifiers [12] [13] [14]. These devices could be also used as mixers [15], THz mirrors [16], and THz sources [17] [18]. "
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    ABSTRACT: The terahertz SPICE FET model has been experimentally validated in Si CMOS and InGaAs HEMTs up to 4.5 THz and updated to account for parasitic gate fringing capacitance and parasitic source and drain resistance. The model is in good agreement with experimental data at low and high THz field intensities. We also show that introducing additional capacitances linking the drain and gate electrodes may lead to enhancement of the THz plasmonic detector response at lower THz frequencies. The simulation results of the plasmonic detector response to a single terahertz pulse are in good agreement with our measured data.
    Full-text · Article · Feb 2015 · Solid-State Electronics
    • "Detection of THz radiation by plasmonic nonlinearities in a 2D electron channel of a field-effect transistor (FET) was originally proposed by Dyakonov and Shur [1]. Resonant (frequency selective) [3], [4], [12], [13] as well as nonresonant (broadband) [10], [14] plasmonic detectors have been studied. The frequencies of the plasmon resonances in the FET channel with asymmetric boundary conditions are given by [21] "
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    ABSTRACT: We report on room-temperature plasmonic detection of the thermal emission from a black body in the terahertz and mid-infrared domains by dual-grating-gate InAlAs/InGaAs/InP high electron mobility transistors (HEMTs). In such detectors, the asymmetric grating gate of a large area acts as an effective antenna that improves the performance in the two spectral domains.
    No preview · Conference Paper · Sep 2014
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