Microfabrication of silicon–nitride micromesh bolometric detectors for Planck high frequency instrument

Abstract

The high frequency instrument (HFI) on the National Aeronautics and Space Administration/European Space Agency Planck Surveyor, scheduled for launch in 2007, will map the entire sky in six frequency bands ranging from 100 to 857 GHz to probe cosmic microwave background anisotropy and polarization with angular resolution ranging from 9[prime] to 5[prime]. The HFI focal plane will contain 48 silicon–nitride micromesh bolometers operating from a 100 mK heat sink. Four detectors in each of the six bands will detect unpolarized radiation. An additional four pairs of detectors will provide sensitivity to linear polarization of emissions at 143, 217, and 353 GHz. We have fabricated and developed sensitive Si3N4 micromesh spider-web bolometers for submillimeter observation using microelectromechanical system techniques. The spiderweb architecture in this research provides high infrared absorption with minimal heat capacity and volume.