TY - JOUR
T1 - Bismuth X-ray absorber studies for TES microcalorimeters
AU - Sadleir, J. E.
AU - Bandler, S. R.
AU - Brekosky, R. P.
AU - Chervenak, J.
AU - Figueroa-Feliciano, E.
AU - Finkbeiner, F.
AU - Iyomoto, N.
AU - Kelley, R. L.
AU - Kilbourne, C. A.
AU - King, J. M.
AU - Porter, F. S.
AU - Robinson, I. K.
AU - Saab, T.
AU - Talley, D. J.
PY - 2006/4/14
Y1 - 2006/4/14
N2 - Bismuth's large atomic number and low carrier density makes it an attractive X-ray absorber material for microcalorimeters. Bismuth's long fermi wavelength and long mean free paths have motivated much interest in the fabrication of high quality bismuth films to study quantum size effects. Despite such incentives, fabrication of high quality bismuth films has proven difficult, and measured properties of such films are highly variable in the literature. Implementing a bismuth deposition process for TES (superconducting Transition Edge Sensor) device fabrication presents additional challenges particularly at interfaces due to the inherent granularity and surface roughness of its films, its low melting point, and its tendency to diffuse and form undesired intermetallic phases. We report observations of Bi-Cu and Bi-Au diffusion in our devices correlating with large shifts in Tc (superconducting transition temperature). Using SEM and in situ R vs T annealing experiments we have been able to study these diffusion processes and identify their activation temperatures.
AB - Bismuth's large atomic number and low carrier density makes it an attractive X-ray absorber material for microcalorimeters. Bismuth's long fermi wavelength and long mean free paths have motivated much interest in the fabrication of high quality bismuth films to study quantum size effects. Despite such incentives, fabrication of high quality bismuth films has proven difficult, and measured properties of such films are highly variable in the literature. Implementing a bismuth deposition process for TES (superconducting Transition Edge Sensor) device fabrication presents additional challenges particularly at interfaces due to the inherent granularity and surface roughness of its films, its low melting point, and its tendency to diffuse and form undesired intermetallic phases. We report observations of Bi-Cu and Bi-Au diffusion in our devices correlating with large shifts in Tc (superconducting transition temperature). Using SEM and in situ R vs T annealing experiments we have been able to study these diffusion processes and identify their activation temperatures.
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U2 - 10.1016/j.nima.2005.12.033
DO - 10.1016/j.nima.2005.12.033
M3 - Article
AN - SCOPUS:33645889652
VL - 559
SP - 447
EP - 449
JO - Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
JF - Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
SN - 0168-9002
IS - 2
ER -