Bonetti, J. A.Turner, A. D.Kenyon, M.Orlando, A.Brevik, J. A.Trangsrud, A.Sudiwala, R.LeDuc, H. G.Nguyen, H. T.Day, P. K.Bock, J. J.Golwala, S. R.Sayers, J.Kovac, JohnLange, A. E.Jones, W. C.Kuo, C. LYoung, BettyCabrera, BlasMiller, Aaron2017-08-042009Bonetti, J. A., A. D. Turner, M. Kenyon, A. Orlando, J. A. Brevik, A. Trangsrud, R. Sudiwala et al. 2009. "Microfabrication and Device Parameter Testing of the Focal Plane Arrays for the Spider and BICEP2/Keck CMB Polarimeters." In Proceedings of AIP Conference Proceedings 1185, Vol 31 (1), Stanford, CA, July 20-24, 2009: 367.http://nrs.harvard.edu/urn-3:HUL.InstRepos:33717522Spider and BICEP2/Keck are projects to study the polarization of the cosmic microwave background (CMB). The focal planes for both require large format arrays of superconducting transition edge sensors (TES's). A major challenge for these projects is fabricating arrays with high uniformity in device parameters. A microfabrication process is described that meets this challenge. The results from device testing are discussed. Each focal plane is composed of 4 square wafers (tiles), and each wafer contains 128 membrane-isolated, polarization-sensitive, antenna-coupled TES's. After processing, selected wafers are pre-screened in a quick-turn-around, cryogen-free, ^He fridge. The pre-screening is performed with a commercial resistance bridge and measures transition temperatures (Tc) and normal state resistances (R„). After pre-screening, 4 tiles at a time are fully characterized in a testbed employing a SQUID readout and SQUID mulitplexing. The tests demonstrate the values of Tc, RB, thermal conductance, g, and the standard deviations of each, across a wafer and from wafer to wafer, are within design specifications.en-USTES bolometerscosmologyCMBcosmic microwave backgroundpolarizationJournal Article10.1063/1.3292354