Microelectronic test structures for the development of a strip sensor technology for high energy physics experiments

Abstract

The planned upgrade of the Large Hadron Collider, the HL-LHC, requires the development of improved tracking silicon sensors for the main CERN experiments. These devices must fulfil the specifications established by the different detectors for the adverse HL-LHC working conditions, in order to guarantee the proper performance of the tracking systems during the lifetime of the experiments. In the framework of the ATLAS Inner-Tracker sensor Market Survey, a prototype strip sensor layout has been designed by the collaboration, and fabricated in 6-inch substrates by Infineon Technologies AG. This work presents a set of test structures included in this prototype, capable to evaluate key device and technological parameters as strip implant resistivity, bias resistance, coupling capacitance, surface currents, or the influence of the sensor edge design in device breakdown voltage. A complete analysis of these parameters before and after proton and gamma irradiations, up to fluences and doses similar to the ones expected in the future HL-LHC experiments, is presented. This study shows the relevance of microelectronic test structures in the development of technologies of tracking silicon sensors for High Energy Physics experiments.