Bolometers with suspended absorbers

A technology for manufacturing suspended bridges to improve the performance of superconducting micro- and nanodevices, sensors and electronic coolers is described. Samples of bolometers and electron coolers of the superconductor-insulator-normal metal-insulator-superconductor (SINIS) structure have been fabricated, in which the strip of normal metal does not touch the substrate, but hangs between the banks of superconducting aluminum. The fabrication technology involves isotropic chemical etching of aluminum and critical point drying, which allows the superconductor layer under the normal bridge to be removed and prevents the bridge from sagging and sticking to the substrate. The current-voltage characteristics of such devices were measured at a temperature of 0.3 K.