Bimetallic Thermal Radiation Microsensor with Integrated Dipole Antenna

In this paper, a bimetallic thermal radiation microsensor with a dipole antenna for detecting electromagnetic waves ranging from infrared to terahertz region is designed, fabricated and evaluated. A cantilevered silicon-aluminum bimetal structure with an absorber at the end is employed as a thermal sensing element. On the basis of the resonant frequency change of the cantilever relying on photothermal conversion, the incident electromagnetic waves can be detected. The dipole antenna is integrated to enhance the electric field intensity at the sensing element and increase the sensitivity of the microsensor. This electric field enhancement effect is simulated by finite difference time domain simulation and it is found that the designed antenna can enhance the electric field several ten times. The frequency variation sensitivity to an incident light is found to be 11 Hz/muW Also, a thermal nose equivalent power of 2times10^-10 W/radicHz is demonstrated.