Development of iridium TES by pulsed laser deposition with a Nd:YAG laser

The use of cryogenics micro calorimeters with Transition Edge Sensors for high-resolution spectroscopy for space applications puts several constraints on the detector's performances. Among several requirements, the long term stability of TES from a chemical and physical point of view is one of the most important. Iridium is a very interesting material for TES fabrication due to its excellent chemical stability and low transition temperature. Starting from the promising results we had with a cryogenic microcalorimeter with TES made of an Ir single crystal, we are developing a procedure to produce patterned Ir thin films by means of the Pulsed Laser Deposition (PLD). PLD with an infrared laser, in UHV, allows very clean evaporation process, good efficiency (about 4 nm/shot) and low dissipated power in the vacuum chamber (about 1 W). We have applied a lift-off mask technique that allows to heat the substrate during the deposition, which improves the adhesion and the thermal conductivity and circumvents the needs of very aggressive etchant solutions. (C) 2003 Elsevier B.V. All rights reserved.