ALMA2030: Development study to develop new SIS process kicks off

Published: 03 Dec 2020
SIS Junctions

A new development study, led by the Group for Advanced Receiver Development (GARD) at Chalmers University in Gothenburg, will develop new processes to fabricate small size Superconductor Insulator Superconductor (SIS) junctions, which are at the heart of the ALMA receivers

This fundamental technology development study aims to adapt the fabrication techniques to increase the instantaneous IF bandwidth of the receivers by a factor of 2 to 4, following one of the key recommendations of the ALMA Development Roadmap.

To achieve this, the GARD group will need to keep tight control over the SIS junction capacitance, which they aim to do by reducing the junction size to <1 µm2. To verify the achieved capacitance, the junctions will be measured in the cryogenic probe station at the National Astronomical Observatory of Japan. The study will initially start looking at junctions for ALMA Bands 6+7, and later try to implement this in Band 9, in collaboration with the Nederlandse Onderzoekschool Voor Astronomie.