Biomolecule sensing in THz range with n-Ge/Si antennas

We present n-doped germanium-on-silicon (Ge-on- Si) antennas fabricated with CMOS mainstream methods, showing resonances between 0.1 and 0.7 THz for sensing applications. After surface functionalization with α-lipoic acid, a red-shift of the antenna resonance is observed, as demonstrated by THz time domain spectroscopy. Similar results are obtained with silicon nitride (Si 3 N 4 )-coated antennas, enabling microfluidic integration. Finally, we compare antennas of bow-tie slots to antennas fabricated via maskless photolithography.