Reliability of thin SiO2films showing intrinsic dielectric integrity

The reliability of 6-10 nm SiO2films is investigated on 0.8 mm²MOS capacitors with polycrystalline silicon electrode in terms of dielectric breakdown. The SiO2films prepared show intrinsic dielectric integrity, that is, time-zero dielectric breakdown field for all capacitors distributes sharply around 10 MV/cm. Accelerated time dependent dielectric breakdown (TDDB) is examined. Electric field acceleration factor and temperature acceleration factor are evaluated. Using these factors, the failure rate for 6-10 nm SiO2is estimated to be less than /hour under a 5 MV/cm at 150°C operating condition. It is concluded that the SiO2films with intrinsic time-zero dielectric breakdown behavior are highly reliable with regard to TDDB and the SiO2films as thin as 6 nm are assured to be applicable to VLSI devices.