Commercial feedhorn-coupled multichroic AlMn-based TES polarimeters on 150 mm wafers

SeeQC-HYPRES is pleased to submit this phase I SBIR proposal to develop optimized processing modules for a fast turn round cryogenic bolometer manufacturing technology on HYPRES’s 150-mm (6-inch)-wafer micro-fabrication line for future cosmic microwave background (CMB) experiments. The developed modules will be tested for scalability to a higher volume while lowing the cost without compromising fabrication yield to meet the requirements of the stage-IV CMB experiments. The number of polarization sensitive detectors need for field deployed CMB experiments has been growing steadily from 1000 of stage- II to 10,000 stage-III and projected detectors count ~500,000 for CMB-S4 experiments. There is a strong community support behind CMB-S4. P5 recommendation: "The Particle Physics Project Prioritization Panel (P5) outlined a strategic plan for US particle physics research over the coming decade in 2014. The panel recommended, "support CMB experiments as part of the core particle physics program. The multidisciplinary nature of the science warrants continued multiagency support." In response to the recommendation, CMB community started planning CMB Stage IV (CMB-S4), which aims to make definitive measurement of the early universe with ~500,000 detectors." Such a task will involve the fabrication of over 500 science grade wafers within a few years. It has increasingly been clear that the next phase of development of detectors for CMB experiments will require well maintained with controlled environments micro-fabrication facilities. SeeQC-HYPRES’ fabrication facility fits this requirement very well. HYPRES is the premier commercial superconductor electronics company in the US equipped with 150 mm wafer processing equipment. Furthermore, the decades of experience with low temperature superconducting electronics fabrication processes gives HYPRES an edge to deliver wafers needed for the CMB experiments. The primary goal of this program is the development of feed-horn coupled detector array technology for future Cosmic Microwave Background experiments. In doing so the project will focus on merging the niobium processes and MEMS processes on a 150 mm wafers. SeeQC-HYPRES has been fabricating CMB detector arrays. The planar antenna-coupled detector fabrication process that we are currently routinely running at SeeQC-HYPRES in collaboration with LBNL have most of processes that carries over to make feedhorn-coupled detectors. The current processes have nine modules, eight of which can be adapted with some process parameters adjusted to make sensitive feedhorn-coupled detectors for various frequency ranges. The process for the last module, which is related to the MEMS release mechanism, needs to be developed. For the antenna coupled detectors this is currently done using XF2 etch through a etch-window on top of the wafer, while the feed-horn coupled detector needs to be done through opening on the back of the silicon wafer with Deep Reactive Ion Etch (DRIE) process. We are excited about developing a process that combines DRIE MEMs process with superconducting microfabrication processes. Such combination has direct application for packaging of Quantum computing devices that is also core of SeeQC-HYPRES’s expertise.