Speaker
Description
The Shirokoff Line-Intensity Mapper (SPT-SLIM) is a pathfinder instrument deployed on the South Pole Telescope, using on-chip superconducting filterbank spectrometers to perform mm-wavelength line-intensity mapping (LIM). Each SPT-SLIM pixel couples incident radiation from a feedhorn-fed orthomode transducer into superconducting microstrip transmission lines, which route the signal to an array of half-wavelength channelizing resonators; each spectral channel is read out with a lumped-element kinetic inductance detector (leKID). Realizing this architecture at the resolution and sensitivity required for LIM has required sustained fabrication development, including hybrid (multi-material) leKID processes and the integration of low-loss dielectrics compatible with low-temperature processing to preserve resonator performance. We describe the fabrication process flow for the SPT-SLIM spectrometer chips and present results from material and device characterization — including microstrip loss extraction and spectral bandpass characterization of fabricated filterbanks. We connect these lab-based fabrication results to the as-built performance of the array that was deployed and successfully operated during SPT-SLIM's first observing season, and outline fabrication-driven upgrades planned for the next deployment.