Backside doping profiles of irradiated silicon detectors

Silicon detectors are used in High Energy Physics (HEP) experiments as tracking and vertexing devices. The damage caused by radiation is of special interest for sensors to be used at the HL-LHC. The doping profiles of highly irradiated sensors can neither be measured with common capacitance voltage methods nor with methods of chemical analysis. Nevertheless, they need to be known for damage modelling or for simulations of the sensor performance. In this paper it is shown that highly neutron irradiated doping profiles can be measured by using a spreading resistance probe technique. It turned out that the implantation depth of the profiles of active dopants decreases with increasing fluences.