RADIATION HARD MONOLITHIC CMOS SENSORS WITH SMALL ELECTRODE SIZE FOR THE ATLAS EXPERIMENT IN THE HL-LHC

Mini-MALTA is a Monolithic Active Pixel Sensor prototype developed in the TowerJazz 180 nm CMOS imaging process, with a small collection electrode design (3 um), and a small pixel size (36.4 um), on high resistivity substrates and large voltage bias. It targets the outermost layer of the ATLAS ITK Pixel detector for the HL-LHC. This design addresses the pixel in-efficiencies observed in MALTA and TJ- Monopix to meet the radiation hardness requirements. This contribution will present the results from characterisation in particle beam tests that show full efficiency up to 1e15 neq/cm2 and 70 Mrad.