SOI-based micro-mechanical terahertz detector operating at room-temperature and atmospheric pressure

Kevin Froberger (1, 2) , Benjamin Walter (3) , Melanie Lavancier (1, 2) , Romain Peretti (1, 2) , Guillaume Ducournau (1, 2) , Jean-Francois Lampin (2, 1) , Marc Faucher (1, 4) , Stefano Barbieri (1, 2)

1 IEMN - Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520
2 PHOTONIQUE THZ - IEMN - Photonique THz - IEMN
3 Vmicro SAS
4 NAM6 - IEMN - Nano and Microsystems - IEMN

We present a micro-mechanical terahertz (THz) detector fabricated on a silicon on insulator substrate and operating at room-temperature. The device is based on a U-shaped cantilever of micrometric size, on top of which two aluminum half-wave dipole antennas are deposited. This produces an absorption extending over the [Formula: see text] THz frequency range. Due to the different thermal expansion coefficients of silicon and aluminum, the absorbed radiation induces a deformation of the cantilever, which is read out optically using a 1.5 μm laser diode. By illuminating the detector with an amplitude modulated, 2.5 THz quantum cascade laser, we obtain, at room-temperature and atmospheric pressure, a responsivity of [Formula: see text] for the fundamental mechanical bending mode of the cantilever. This yields noise-equivalent-power of [Formula: see text] at 2.5 THz. Finally, the low mechanical quality factor of the mode grants a broad frequency response of approximately 150 kHz bandwidth, with a thermal response time of ∼ 2.5 μs.

Mots clés: Antennas; Terahertz detectors; Silicon-on-insulator; Thermal effects

Domaines: Sciences de l'ingénieur [physics]

Kevin Froberger, Benjamin Walter, Melanie Lavancier, Romain Peretti, Guillaume Ducournau, et al.. SOI-based micro-mechanical terahertz detector operating at room-temperature and atmospheric pressure. Applied Physics Letters, 2022, 120 (26), pp.261103. ⟨10.1063/5.0095126⟩. ⟨hal-03742065⟩