Interface chemistry of pristine TiN/La:Hf0.5Zr0.5O2 capacitors

We present a hard and soft x-ray photoelectron spectroscopy study of the interface chemistry in pristine TiN/La-doped Hf0.5Zr0.5O2/TiN capacitors. An oxynitride phase (∼1.3 nm) is formed at the top interface, while a TiO2−δ phase was detected near the bottom interface. The oxygen vacancy (VO) concentration is higher at the top interface than in the film due to oxygen scavenging by the top electrode. The VO concentration was also found to increase from ∼1.5 to 1.9 × 1020 cm−3 when increasing La doping from 1.7 to 2.7 mol. %. Two La dopants are compensated by the formation of one positively charged VO.