Seifert Marietta
Leibniz IFW Dresden, Helmholtzstraße 20, 01069 Dresden, Germany.
Materials (Basel). 2020 Apr 1;13(7):1605. doi: 10.3390/ma13071605.
This paper reports on a significant further improvement of the high temperature stability of RuAl thin films (110 nm) on the piezoelectric Ca 3 TaGa 3 Si 2 O 14 (CTGS) and La 3 Ga 5 SiO 14 (LGS) substrates. RuAl thin films with AlN or SiO 2 cover layers and barriers to the substrate (each 20 nm), as well as a combination of both were prepared on thermally oxidized Si substrates, which serve as a reference for fundamental studies, and the piezoelectric CTGS, as well as LGS substrates. In some films, additional Al layers were added. To study their high temperature stability, the samples were annealed in air and in high vacuum up to 900 °C, and subsequently their cross-sections, phase formation, film chemistry, and electrical resistivity were analyzed. It was shown that on thermally oxidized Si substrates, all films were stable after annealing in air up to 800 °C and in high vacuum up to 900 °C. The high temperature stability of RuAl thin films on CTGS substrates was improved up to 900 °C in high vacuum by the application of a combined AlN/SiO 2 barrier layer and up to 800 °C in air using a SiO 2 barrier. On LGS, the films were only stable up to 600 °C in air; however, a single SiO 2 barrier layer was sufficient to prevent oxidation during annealing at 900 °C in high vacuum.
本文报道了钌铝（RuAl）薄膜（110纳米）在压电材料钽镓硅钙石（Ca₃TaGa₃Si₂O₁₄，CTGS）和镧镓硅石（La₃Ga₅SiO₁₄，LGS）衬底上高温稳定性的显著进一步提升。在热氧化硅衬底（用作基础研究的参考）、压电材料CTGS以及LGS衬底上制备了带有氮化铝（AlN）或二氧化硅（SiO₂）覆盖层以及与衬底之间的阻挡层（各20纳米）的RuAl薄膜，以及二者组合的薄膜。在一些薄膜中还添加了额外的铝层。为研究其高温稳定性，将样品在空气和高达900℃的高真空环境中进行退火，随后对其横截面、相形成、薄膜化学性质以及电阻率进行分析。结果表明，在热氧化硅衬底上，所有薄膜在高达800℃的空气中退火以及高达900℃的高真空环境中退火后均保持稳定。通过应用AlN/SiO₂组合阻挡层，RuAl薄膜在CTGS衬底上在高真空环境中的高温稳定性提升至900℃，使用SiO₂阻挡层在空气中则提升至800℃。在LGS衬底上，薄膜在空气中仅在高达600℃时保持稳定；然而，单个SiO₂阻挡层足以防止在900℃的高真空退火过程中发生氧化。
