Superconductor-insulator-normal junctions for self-refrigerating thin-film bolometers

Electronic refrigeration by Peltier effect in superconductor-insulator-normal (SIN) junctions allows to cool down electrons in a metal and achieve an operating temperature of about 100mK, or even lower. We will review the theory for obtaining electronic on-chip refrigeration, the state of art of fabrication and some results concerning our SIN junctions necessary to develop the refrigerator. We investigated two types of junctions consisting in a case of a sandwich made by Nb/AlOx/Cu and in the other case by Al/AlOx/Cu.