Width dependence of platinum and titanium thermistor characteristics for application in room-temperature antenna-coupled terahertz microbolometer

Banerjee, Amit; Satoh, Hiroaki; Tiwari, Ajay; Apriono, Catur; Rahardjo, Eko Tjipto; Hiromoto, Norihisa; Inokawa, Hiroshi

doi:10.7567/jjap.56.04cc07

Cited by 23 publications

(16 citation statements)

References 30 publications

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“…It is worth recalling that the gap between the antenna’s arm is limited to 11.5 μm. Our group had established that a narrower thermistor reduces TCR but increases resistivity [ 52 ]. For the present design, we focus on one thermistor design width of 0.1 μm.…”

Section: Resultsmentioning

confidence: 99%

Responsivity and NEP Improvement of Terahertz Microbolometer by High-Impedance Antenna

Aji

Satoh

Apriono

et al. 2022

Sensors

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The antenna-coupled microbolometer with suspended titanium heater and thermistor was attractive as a terahertz (THz) detector due to its structural simplicity and low noise levels. In this study, we attempted to improve the responsivity and noise-equivalent power (NEP) of the THz detector by using high-resistance heater stacked on the meander thermistor. A wide range of heater resistances were prepared by changing the heater width and thickness. It was revealed that the electrical responsivity and NEP could be improved by increasing the heater’s resistance. To make the best use of this improvement, a high-impedance folded dipole antenna was introduced, and the optical performance at 1 THz was found to be better than that of the conventional halfwave dipole antenna combined with a low-resistance heater. Both the electrical and optical measurement results indicated that the increase in heater resistance could reduce the thermal conductance in the detector, thus improved the responsivity and NEP even if the thermistor resistance was kept the same.

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Section: Resultsmentioning

confidence: 99%

Responsivity and NEP Improvement of Terahertz Microbolometer by High-Impedance Antenna

Aji

Satoh

Apriono

et al. 2022

Sensors

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“…Hence in this report we qualitatively predict the optimum proximity between FDA arms is 2 μm to obtain highest resistance with any number of arms. While in the narrow width case, the decaying resistance can be explained by the size effect caused from the mean free path of conduction electrons, which limits the electrical properties of a metal [20]. From the input impedance simulation results, it is concluded that a proper design process is critical when applying FDA to select desired resonant resistance for the impedance matching with the bolometer.…”

Section: A Radiating Modementioning

confidence: 99%

Folded-Dipole Antenna Geometrical Analysis for THz Microbolometer

et al. 2023

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To improve the responsivity of terahertz (THz) antenna-coupled bolometer, heater (load) resistance has to be increased to suppress the thermal conduction and realize larger temperature rise of the thermistor. Proper design of antenna is therefore essential to assure the impedance matching between antenna and heater. From this viewpoint, a high-impedance folded-dipole antenna (FDA) has been studied numerically by the finite element simulation. The effect of FDA structural parameters such as number of arms, antenna width, and arm spacing are discussed with the lumped port and resistive heater coupled to the antenna gap for the cases of radiating and receiving modes, respectively. The product of resonant resistance and area efficiency is used to predict the improvement made by FDA as a figure of merit (FOM) correlated to the bolometer responsivity. This study revealed that the optimum FOM in FDA-coupled bolometer operating at 1 THz was obtained with three arms, 1-μm antenna width and 4-μm arm spacing. A comparison was made with the result from a half-wave dipole antenna and revealed that FDA could enhance the bolometer responsivity by a factor of 15. This research demonstrated the effectiveness of the FDA to improve the performance of THz antenna-coupled bolometer for applications such as imaging for non-destructive inspection.

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“…Bolometers without an antenna of the present work were fabricated by the standard Si CMOS technology instead of the complex non-standard lift-off process used in our previously reported works [44,45]. The key advantages of the Si CMOS technology are good reproducibility and universalities of the results.…”

Section: Structure Of Antenna-coupled Bolometersmentioning

confidence: 99%

Performance Comparison of SOI-Based Temperature Sensors for Room-Temperature Terahertz Antenna-Coupled Bolometers: MOSFET, PN Junction Diode and Resistor

et al. 2020

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Assuming that the 0.6-μm silicon-on-insulator (SOI) complementary metal–oxide–semiconductor (CMOS) technology, different Si-based temperature sensors such as metal-oxide-semiconductor field-effect transistor (MOSFET) (n-channel and p-channel), pn-junction diode (with p-body doping and without doping), and resistors (n+ or p+ single crystalline Si and n+ polycrystalline Si) were designed and characterized for its possible use in 1-THz antenna-coupled bolometers. The use of a half-wave dipole antenna connected to the heater end was assumed, which limited the integrated temperature sensor/heater area to be 15 × 15 µm. Our main focus was to evaluate the performances of the temperature sensor/heater part, and the optical coupling between the incident light and heater via an antenna was not included in the evaluation. The electrothermal feedback (ETF) effect due to the bias current was considered in the performance estimation. A comparative analysis of various SOI bolometers revealed the largest responsivity (Rv) of 5.16 kV/W for the n-channel MOSFET bolometer although the negative ETF in MOSFET reduced the Rv. The noise measurement of the n-channel MOSFET showed the NEP of 245 pW/Hz1/2, which was more than one order of magnitude smaller than that of the n+ polycrystalline Si resistive bolometer (6.59 nW/Hz1/2). The present result suggests that the n-channel MOSFET can be a promising detector for THz applications.

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Width dependence of platinum and titanium thermistor characteristics for application in room-temperature antenna-coupled terahertz microbolometer

Cited by 23 publications

References 30 publications

Responsivity and NEP Improvement of Terahertz Microbolometer by High-Impedance Antenna

Responsivity and NEP Improvement of Terahertz Microbolometer by High-Impedance Antenna

Folded-Dipole Antenna Geometrical Analysis for THz Microbolometer

Performance Comparison of SOI-Based Temperature Sensors for Room-Temperature Terahertz Antenna-Coupled Bolometers: MOSFET, PN Junction Diode and Resistor

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