Hafnium Transition Edge Sensor Bolometer for Cosmic Microwave Background Experiments

SEEQC together with LBNL are pleased to submit this phase-I SBIR proposal to develop a fabrication process for commercial manufacturing of Hafnium Transition Edge Sensor Bolometers for Cosmic Microwave Background Experiments. The project's objective is to develop a Hafnium Transition Edge Sensor (TES) bolometer array for Cosmic Microwave Background (CMB) experiments that is aligned with the evolving needs of the field. One of the key challenges facing next-generation CMB experiments is the need for a substantial increase in fabrication throughput to meet the growing demand. As CMB experiments scale up in terms of the number of detectors and the complexity of observations, a streamlined and efficient production process becomes essential. Engaging in process development through the SBIR program represents a sensible choice, as it provides the ideal platform to partner with industry experts and leverage the expertise in achieving large-volume production. Collaborating with industry partners offers several advantages, including access to advanced manufacturing techniques, economies of scale, and the ability to benefit from industry best practices. By simplifying fabrication and improving yield, repeatability, and performance, not only will the experiments become more cost-effective, but they will also be better positioned to meet their ambitious timelines. This, in turn, will accelerate scientific progress and the quest for transformative discoveries in cosmology. This initiative exemplifies the spirit of innovation and collaboration that drives scientific progress in the field of cosmology. During Phase I we will integrate the Hf TES bolometer into CMB detector arrays. We have successfully fabricated standalone Hf TESs as well as CMB-S4 detector arrays with AlMn TESs. We will leverage this experience to modify the fabrication process flow of the CMB detector array to allow for a seamless integration of the Hf TES. Due to the nature of the Hf deposition, this will require us to process the TES first. This is a critical measure of success, as it ensures that the introduction of Hf TES technology does not compromise the reliability and performance of the overall detector array. During Phase I we will demonstrate that the Hafnium TES fabrication process is repeatable and stable. The ability to maintain stability and consistency throughout the integrated fabrication process is essential for boosting the yield and efficiency of detector array production for the CMB-S4 project.