Probing ABCStar Front-End Readout ASICs for the new ATLAS Inner Tracker

The ABCStar is a front-end ASIC implemented in a commercial 130 nm CMOS process designed for readout of the ATLAS ITk Silicon Strip sensors for the HL-LHC at CERN. The analog and digital circuitry of over 330,000 ASICs needs to be thoroughly tested to ensure they can accurately process the high rate of collision data within the HL-LHC and last throughout the lifetime of the detector. There are two probing sites to test the ABCStar ASICs on wafers containing 470 devices – a dedicated probing station at Rutherford Appleton Laboratory (RAL) and a specialist wafer testing company in Canada collaborating with Carleton University – with half being tested at each site. Probing at these two sites has bridged the methodological, technical and semantic gap between research facilities and the semiconductor testing industry. We report on the performance of the final design of the ABCstar ASIC and on the cross-checks between the two probing sites that demonstrated 99.8% agreement on test results from pre-production.