SUSPENDED YBACUO MICROBOLOMETERS ON MICRO MACHINED SI OR SIMOX SUBSTRATES

The improvement of the bolometer performances is obtained by thermally insulating the sensitive region. The results we have measured in the 3-5 mu m wavelength range on a YBaCuO suspended membrane, with an opti mised geometry and without any absorbing layer, are among the best rep orted. However, to meet the requirements of spatial observations, thes e microbolometers must be covered by an absorbing layer adapted to wor k at wavelengths larger than 20 mu m. In order to compensate for the i ncrease of the thermal mass brought by the absorber, and thus the unde sirable increase of the response time, we suggest the simultaneous add ition of a layer with a higher thermal conductivity to the suspended m embrane.