GEOMETRY-EFFECTS ON THE RESPONSE OF A SUPERCONDUCTING TUNNEL JUNCTIONDETECTOR

Superconductive tunnel junction detectors are promising as next genera tion X-ray detectors. By means of Low Temperature Scanning Electron Mi croscopy, the inhomogeneities in the response of this type of detector s are investigated. Spatial variations in the quasiparticle life time and the quasiparticle tunnel time are reasons for inhomogeneity in the response. In this article junctions with two different counter electr ode geometries are compared. It is shown that the response homogeneity of a junction with a wiring layer fully covering the counter electrod e is better than the response of a junction in which the counter elect rode is contacted by means of a contact pad.