Yoshimoto Takuya, Goto Taichi, Takagi Hiroyuki, Nakamura Yuchi, Uchida Hironaga, Ross Caroline A, Inoue Mitsuteru
Department of Electrical and Electronic Information Engineering, Toyohashi University of Technology, 1-1 Hibari-Ga-Oka, Tempaku, Toyohashi, Aichi, 441-8580, Japan.
JST, PRESTO, 4-1-8 Honcho, Kawaguchi, Saitama, 332-0012, Japan.
Sci Rep. 2017 Oct 23;7(1):13805. doi: 10.1038/s41598-017-14184-4.
Thin film oxide materials often require thermal treatment at high temperature during their preparation, which can limit them from being integrated in a range of microelectronic or optical devices and applications. For instance, it has been a challenge to retain the optical properties of Bragg mirrors in optical systems at temperatures above 700 °C because of changes in the crystalline structure of the high-refractive-index component. In this study, a ~100 nm-thick amorphous film of tantalum oxide and yttrium oxide with an yttrium-to-tantalum atomic fraction of 14% was prepared by magnetron sputtering. The film demonstrated high resistance to annealing above 850 °C without degradation of its optical properties. The electronic and crystalline structures, stoichiometry, optical properties, and integration with magnetooptical materials are discussed. The film was incorporated into Bragg mirrors used with iron garnet microcavities, and it contributed to an order-of-magnitude enhancement of the magnetooptical figure of merit at near-infrared wavelengths.
薄膜氧化物材料在制备过程中通常需要高温热处理，这可能会限制它们集成到一系列微电子或光学器件及应用中。例如，由于高折射率组分的晶体结构发生变化，在温度高于700°C的光学系统中保持布拉格镜的光学性能一直是一个挑战。在本研究中，通过磁控溅射制备了一种钽氧化物和钇氧化物的约100nm厚非晶薄膜，钇与钽的原子分数为14%。该薄膜在高于850°C的退火条件下表现出高抗性，且其光学性能不会退化。文中讨论了该薄膜的电子和晶体结构、化学计量、光学性能以及与磁光材料的集成。该薄膜被并入与铁石榴石微腔一起使用的布拉格镜中，在近红外波长下，它使磁光品质因数提高了一个数量级。
