Correlation between dopant reduction and interfacial defects in low-energy x-ray-irradiated MOS capacitors

We discuss effects associated with dopant reduction and interface defects generated in p-type metal-oxide semiconductor (MOS) capacitors exposed to doses of low-energy x-ray radiation up to 500 Mrad (Si). The dependence on dose, size, oxide charge and interface trapped charge density suggests that the dopant-reduction behaviour is influenced by the oxide and interface charges and their behaviour during and after irradiation. In particular, the interfacial defect generation dynamics suggests that mechanisms associated with tunnelling of carriers at the SiO2/Si interface may be involved.