In this study we compared the charge trapping characteristics of low pressure chemical vapour deposited (LPCVD) oxide and remote plasma enhanced chemical vapour deposited (RPECVD) oxide with two types of thermally grown oxide, namely high-pressure grown oxide (HIPOX) and the standard thermal dry oxide. The deposited oxides show enhanced Fowler-Nordheim tunnelling currents compared with the thermal oxides. Our results an charge trapping characteristics under high-field stressing and irradiation show that the deposited oxides exhibit very large electron trapping compared with the grown oxides and that these electron traps in the deposited oxides reside close to the Si-SiO2 interface and hence can affect the device reliability.