THz Antenna-Coupled Microbolometer with 0.1-μm-wide Titanium Thermistor

Antenna-coupled microbolometers to detect terahertz wave were fabricated and their characteristics were evaluated at room temperature. The microbolometer consists of an integrated heater-thermistor and half-wave dipole antenna designed for 1 THz. The width of the Ti thermistor is made as narrow as 0.1 μm by electron beam lithography, and meander shape with longer effective length of thermistor is adopted to realize higher electrical resistance and to improve responsivity. The electrical responsivity for meander shape was 255 V/W, which was more than four times higher than that for the straight one. The electrothermal circuit simulation was carried for better understanding of the observed results. Optical characterization of the bolometer with half-wave dipole antenna in the frequency range from 0.955 to 1.065 THz suggested that the Ti microbolometer was a promising device for detecting the electromagnetic waves in 1-THz frequency region.