A robust, efficient process to produce scalable, superconducting kilopixel far-IR detector arrays

Abstract

Robust, high sensitivity kilopixel format arrays with large focal plane filling factors and low cosmic ray cross sections that operate over the entire far-IR regime are required for future NASA missions, such as Origins and a future far-IR Probe. Our kilopixel Backshort Under Grid (BUG) detectors are designed to meet all those requirements: By bump-bonding two-dimensional detector arrays to readout multiplexers are gaplessly tileable in one spatial direction with the integration of the multiplexer scalable beyond wafer sizes. The detector arrays provide high filling factors (<90% at 1mm pixel pitch) and are designed for low Cosmic ray cross sections. The major missing technology is a detector array architecture that can be gaplessly tiled to deliver the desired pixel counts of npixel ~105, while being providing a robust process to produce these detector arrays. We introduce a new array architecture that is very flexible allowing for a variety of tileable solutions and describe its individual components and the tests of those. Our results demonstrate that this architecture allows for flexible designs with high yields and reliable superconducting bump-bond connections of detectors and the cold readout SQUID multiplexers directly under the detector array, or on a different board that can be connected with e.g. flex lines for compact tiling.