Low-field carrier mobilities in silicon irradiated to extreme fluences

Abstract

The low-field carrier mobilities in <100> silicon were quantified as a function of the 1MeV neutron-equivalent fluence up to $10^{18}$cm${}^{-2}$ and for temperatures between 230K and 260K. Current measurements were fitted using a mobility model for scattering at ionized impurities. Technology-aided design (TCAD) simulations were compared to measurements and used to estimate the carrier concentrations, which are parameters in the fit. The fit model describes the data very well, both as a function of fluence and the temperature. At a fluence of $6\cdot 10^{17}$cm${}^{-2}$, which is expected for the innermost detector layers at the proposed Future Circular Hadron Collider (FCC-hh), the sum of the mobilities of electrons and holes was found to decrease by $\sim 60$%.

21st "Trento" Workshop on Advanced Silicon Radiation Detectors