Silicon microcalorimeters for high energy resolution spectroscopy

Integrated bolometers of a volume of about 0.05 mm3 are fabricated by the technique of silicon micromachining. As thermistor serves a heavily phosphorus doped area implanted in the absorber surface. The optimum thermistor doping was determined with respect to a high resistance gradient, but at the same time with resistance values low enough for providing signals which are reasonably high. Measurements of low-energetic γ-rays and conversion electrons indicated the high sensitivity of our detectors, however unfortunately for picking up noise, too. The steps to improve the current energy resolution are reported.