The Simons Observatory: Production-Level Fabrication of the Mid- and Ultra-High-Frequency Wafers

Published

May 4, 2024

Author(s)

Shannon Duff, Jason Austermann, James Beall, David Daniel, Johannes Hubmayr, Gregory Jaehnig, Bradley Johnson, Dante Jones, Michael J. Link, Tammy Lucas, Rita Sonka, Suzanne Staggs, Joel Ullom, Yuhan Wang

Abstract

The Simons Observatory (SO) is a cosmic microwave background instrumentation suite in the Atacama Desert of Chile. More than 65,000 polarization-sensitive transition-edge sensor (TES) bolometers will be fielded in the frequency range spanning 27 to 280 GHz, with three separate dichroic designs. The mid-frequency 90/150 GHz and ultra-high-frequency 220/280 GHz detector arrays, fabricated at NIST, account for 39 of 49 total detector modules and implement the feedhorn-fed orthomode transducer (OMT)-coupled TES bolometer architecture. A robust production-level fabrication framework for these detector arrays and monolithic DC/RF routing wafers has been developed, which includes single device prototyping, process monitoring techniques, in-process metrology, and cryogenic measurements of critical film properties. Application of this framework has resulted in timely delivery of nearly 100 total superconducting focal plane components to SO with 88% of detector wafer starts meeting criteria for integration into a detector module with a channel yield > 95% and Tc in the targeted range.

Citation

Journal of Low Temperature Physics

Volume

216

Pub Type

Journals

Download Paper

https://doi.org/10.1007/s10909-024-03117-x

Local Download

Keywords

transition-edge sensor, cosmic microwave background, microfabrication, bolometer

Citation

Duff, S. , Austermann, J. , Beall, J. , Daniel, D. , Hubmayr, J. , Jaehnig, G. , Johnson, B. , Jones, D. , Link, M. , Lucas, T. , Sonka, R. , Staggs, S. , Ullom, J. and Wang, Y. (2024), The Simons Observatory: Production-Level Fabrication of the Mid- and Ultra-High-Frequency Wafers, Journal of Low Temperature Physics, [online], https://doi.org/10.1007/s10909-024-03117-x, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=956921 (Accessed May 24, 2025)