Development of molybdenum-gold proximity bilayers as transition edge sensors for the SPEED camera

Bolometers are being developed with thermistor elements using Mo/Au proximity bilayers as superconducting transition edge sensor. These bolometers will be used by the Spectral Energy Distribution camera which is being developed to study the spectral energy distribution of high redshift galaxies. The bolometers are fabricated on 11x11 mm2 suspended 0.5 μm thick low-stress LPCVD silicon nitride films supported by 475 μm thick silicon frames. To obtain the required thermal conductivity, the films are perforated to form central disks suspended by thin legs. Here we discuss the design, fabrication process, and current test results of these bolometers