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Advanced ACTPol Multichroic Polarimeter Array Fabrication Process for 150 mm Wafers



Shannon M. Duff, Gene C. Hilton, Johannes Hubmayr, James A. Beall, Jason E. Austermann, Daniel T. Becker, Jeffrey L. Van Lanen


Advanced ACTPol is a third generation cosmic microwave background (CMB) receiver, deploying in 2016 on the Atacama Cosmology Telescope (ACT) in the Atacama desert of Chile. Spanning five frequency bands from 25 – 280 GHz and having a total of nearly 5800 transition edge sensor (TES) bolometers, the Advanced ACTPol receiver will exhibit increased sensitivity and mapping speed compared to previously fielded ACT recievers. This work presents the fabrication processes developed by NIST to scale to large arrays of feedhorn-coupled multichroic AlMn-based TES polarimeters on 150 mm diameter wafers. In addition to descriptions of the methods used to streamline the fabrication process to enable high yields of densely packed detectors across larger wafer surface areas, we also report details of additional process improvements and the resulting performance improvements.
Journal of Low Temperature Physics


AlMn, cosmic microwave background, multichroic, polarimeter, transition edge sensor
Created July 22, 2015, Updated March 26, 2018