A transition-edge hot electron microbolometer for cosmology experiments.
We are currently developing a Transition-Edge Hot Electron Microbolometer (THM) suitable for the observation of Cosmic Microwave Background polarization anisotropies. It is designed as a micron-sized thin superconducting bilayer deposited on a silicon substrate and it relies on the hot electron effect to achieve thermal isolation from the substrate, thus reaching high sensitivity together with low noise levels at sub-Kelvin temperatures. The fabrication of this kind of detector is possible exploiting electron beam lithography. We are planning to fabricate a Cu/Al THM prototype for astrophysical observations and to test it criogenically at $\sim 300$ mK.