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arXiv · 2402.06553

On the influence of annealing on the compositional and crystallographic properties of sputtered Li-Al-O thin films

Florian Lourens·Detlef Rogalla·Ellen Suhr·Alfred Ludwig
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Abstract

A Li-Al-O thin film materials library, deposited by inert magnetron sputtering and post-deposition annealing in O2 atmosphere, was used to study the effects of different annealing temperatures (300 to 850°C) and durations (1 min to 7 h) on crystallinity and composition of the films. XPS depth profiling revealed inhomogeneous compositional depth profiles with Li contents increased toward the film surface and Al contents toward the film-substrate interface. These depth profiles were confirmed by a combination of RBS and D-NRA. At annealing temperatures of 550°C and higher, Li reacted with the Si substrate. At the same time, temperatures of 550°C and higher enabled the formation of crystalline LiAlO2, whereas at lower temperatures, no crystalline Li-Al-O phases were detected with XRD. In contrast to conventional annealing in a tube furnace (3 to 7 h durations), rapid thermal annealing with fast heating/cooling rates of 10°C/min and durations of 1 to 10 min resulted in homogeneous depth profiles, while also leading to crystalline LiAlO2.

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Florian Lourens, Detlef Rogalla, Ellen Suhr, Alfred Ludwig. 2024-02-09. On the influence of annealing on the compositional and crystallographic properties of sputtered Li-Al-O thin films. https://doi.org/10.1002/adem.202400602

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