Lawniczak-Jablonska Krystyna, Wolska Anna, Kuzmiuk Piotr, Rejmak Pawel, Kosiel Kamil
Institute of Physics, Polish Academy of Sciences Al. Lotników 32/46 02-668 Warsaw Poland
Łukasiewicz Research Network - Institute of Electron Technology Al. Lotników 32/46 02-668 Warsaw Poland.
RSC Adv. 2019 Nov 4;9(61):35727-35734. doi: 10.1039/c9ra07318c. eCollection 2019 Oct 31.
The experimental and theoretical studies of the local atomic order and chemical binding in tantalum oxide amorphous films are presented. The experimental studies were performed on thin films deposited at the temperature of 100 °C by atomic layer deposition on silicon (100) and glass substrates. Thin films of amorphous tantalum oxide are known to exhibit an extremely large extent of oxygen nonstoichiometry. Performed X-ray absorption and photoelectron studies indicated the oxygen over-stoichiometric composition in the considered films. Surplus oxygen atoms have 1s electron level with binding energy about 1 eV higher than these in reference TaO oxide. The density functional theory was applied to find the possible location of additional oxygen atoms. Performed calculation indicated that additional atoms may form the dumbbell defects, which accumulate the dangling oxygen bonds in orthorhombic structure and lead to increase of oxygen 1s level binding energy. The presence of this kind of oxygen-oxygen bonding may be responsible for increase of amorphous film chemical resistivity which is very important in many applications.
本文介绍了氧化钽非晶薄膜中局部原子序和化学键合的实验与理论研究。实验研究是在通过原子层沉积在硅（100）和玻璃基板上于100°C温度下沉积的薄膜上进行的。已知非晶氧化钽薄膜表现出极大程度的氧非化学计量比。进行的X射线吸收和光电子研究表明，所研究的薄膜中存在氧过化学计量组成。多余的氧原子具有1s电子能级，其结合能比参考TaO氧化物中的高约1eV。应用密度泛函理论来寻找额外氧原子的可能位置。进行的计算表明，额外的原子可能形成哑铃状缺陷，这些缺陷在正交结构中积累悬空氧键并导致氧1s能级结合能增加。这种氧-氧键合的存在可能是导致非晶薄膜化学电阻率增加的原因，这在许多应用中非常重要。
