Identification of the atomic scale defects involved in radiation damage in HfO/sub 2/ based MOS devices

Abstract

We have identified the structure of three atomic scale defects which almost certainly play important roles in radiation damage in hafnium oxide based metal oxide silicon technology. We find that electron trapping centers dominate the HfO/sub 2/ radiation response. We find two radiation induced trapped electron centers in the HfO/sub 2/: an O/sub 2//sup -/ coupled to a hafnium ion and an HfO/sub 2/ oxygen vacancy center which is likely both an electron trap and a hole trap. We find that, under some circumstances, Si/dielectric interface traps similar to the Si/SiO/sub 2/ P/sub b/ centers are generated by irradiation. Our results show that there are very great atomic scale differences between radiation damage in conventional Si/SiO/sub 2/ devices and the new Si/dielectric devices based upon HfO/sub 2/.