Performance of Irradiated RD53A 3D Pixel Sensors

Abstract

The ATLAS experiment at the LHC will replace its current inner tracker system for the HL-LHC era. 3D silicon pixel sensors are being considered as radiation-hard candidates for the innermost layers of the new fully silicon-based tracking detector. 3D sensors with a small pixel size of $50\times 50\hat{\mathrm{I}}¼{\mathrm{m}}^2$ and $25\times 100\hat{\mathrm{I}}¼{\mathrm{m}}^2$ compatible with the first prototype ASIC for the HL-LHC, the RD53A chip, have been studied in beam tests after uniform irradiation to $5\times 10^{15}{\mathrm{n}}_{\mathrm{eq}}/c{\mathrm{m}}^2$. An operation voltage of only 50 V is needed to achieve a 97% hit efficiency after this fluence.