Mittmann Terence, Michailow Michail, Lomenzo Patrick D, Gärtner Jan, Falkowski Max, Kersch Alfred, Mikolajick Thomas, Schroeder Uwe
NaMLab gGmbH, Noethnitzer Str. 64a, 01187 Dresden, Germany.
Department of Applied Sciences and Mechatronics, 80335 Munich, Germany.
Nanoscale. 2021 Jan 21;13(2):912-921. doi: 10.1039/d0nr07699f.
Thin film metal-insulator-metal capacitors with undoped hafnium oxide and a mixture of hafnium and zirconium oxides are prepared by sputtering from ceramic targets. The influence of the oxygen concentration while sputtering and of the zirconium concentration on the ferroelectric properties is characterized by electrical and structural methods. Depending on the ambient oxygen, the thin undoped hafnium oxide films show distinct ferroelectric properties. The interplay of oxygen and zirconia could improve the ferroelectric properties. By varying the ambient oxygen and zirconia concentration in the films, stabilization of the tetragonal, orthorhombic or monoclinic phase is possible. This phase stabilization is strongly influenced by the pre-existing phase and size of the nanocrystallites in the as-deposited films. In conclusion, the impact of the film stress coming from oxygen vacancies and oxygen interstitials is correlated with the phase and ferroelectric properties.
采用陶瓷靶溅射法制备了具有未掺杂氧化铪以及氧化铪与氧化锆混合物的薄膜金属-绝缘体-金属电容器。通过电学和结构方法表征了溅射过程中氧浓度和锆浓度对铁电性能的影响。根据环境氧气的不同，未掺杂的氧化铪薄膜表现出明显的铁电性能。氧与氧化锆的相互作用可改善铁电性能。通过改变薄膜中的环境氧和氧化锆浓度，可以实现四方相、正交相或单斜相的稳定。这种相稳定受到沉积态薄膜中预先存在的相和纳米微晶尺寸的强烈影响。总之，来自氧空位和氧间隙的薄膜应力的影响与相和铁电性能相关。
