X-ray microcalorimeter arrays fabricated by surface micromachining

We are developing arrays of Mo/Cu transition edge sensor-based detectors for use as X-ray microcalorimeters and sub-millimeter bolometers. We have fabricated 8×8 pixel X-ray microcalorimeter arrays using surface micromachining. Surface-micromachining techniques hold the promise of scalability to much larger arrays and may allow for the integration of in-plane multiplexer elements. In this paper we describe the surface micromachining process and recent improvements in the device geometry that provide for increased mechanical strength. We also present X-ray and heat pulse spectra collected using these detectors.