Electron and Neutron Radiation Damage E ects on a Two - Phase CCD

Ionization and bulk radiation damage e ects in a two-phase CCD, operated in a Multi Pinned Phase (MPP) mode have been evaluated. Two-phase CCD's are one of the candidates for application in the vertex detector of a future linear collider. Flat-band voltage shifts, dark current, dark current spikes and charge transfer e ciency (CTE) were studied on devices, subjected to irradiation with uencies reaching 4:3 10 12 electrons/cm 2 and 8:9 10 9 neutrons/cm 2 . An additional source of dark signal in electron irradiated devices was observed and explained by impact ionization by holes, released by tunneling from defect states near the Si-SiO 2 interface. A model for the CTE in a two-phase CCD as a function of temperature, background charges and clock timing is described. Calculations based on the model are in a good agreement with the experimentally determined values of CTE in electron and neutron irradiated CCD's.