We demonstrate electronic cooling of a suspended AuPd island using superconductor-insulator-normal metal tunnel junctions. This was achieved by developing a simple fabrication method for reliably releasing narrow submicron sized metal beams. The process is based on reactive ion etching and uses a conducting substrate to avoid charge-up damage and is compatible with e.g. conventional e-beam lithography, shadow-angle metal deposition and oxide tunnel junctions. The devices function well and exhibit clear cooling; up to factor of two at sub-kelvin temperatures.
@article{arxiv.0807.0283,
title = {Electronic cooling of a submicron-sized metallic beam},
author = {J. T. Muhonen and A. O. Niskanen and M. Meschke and Yu. A. Pashkin and J. S. Tsai and L. Sainiemi and S. Franssila and J. P. Pekola},
journal= {arXiv preprint arXiv:0807.0283},
year = {2009}
}