Fabrication of low dimensional oxide thin films using cuprates as sacrificial layers

Yao-Wen Chang^1*, Jhih-Ban Yi¹, Chun-Chien Chiu¹, Yu-Chen Liu¹, Jan-Chi Yang^1,2

¹Department of Physics, National Cheng Kung University, Tainan, Taiwan
²Center for Quantum Frontiers of Research & Technology, National Cheng Kung University, Tainan, Taiwan

* Presenter:Yao-Wen Chang, email:stphen900164chung@gmail.com

The characteristics and functionalities of complex oxides have caught a lot of attention for decades. Despite the fact that the unbounded potential has been examined, one of if not the most challenge for complex oxide is the direct integration of these functional oxides onto devices or substrates that are inherently incompatible in terms of oxide growth.
One solution to the challenge, freestanding process has been proposed, in which etching the inserted sacrificial layer is regarded as one of the most efficient ways to obtain the epitaxial high-quality thin film. In this work, we propose using YBa₂Cu₄O₇ (YBCO) as the sacrificial layer, which dissolves in diluted hydrochloric acid in a more efficient way, while leaving the targeted freestanding film intact. The selected oxide thin film is comprehensively studied before and after the freestanding process via atomic force microscopy, X-ray diffraction, transmission electron microscopy, and electrical transport properties. This approach provides direct integration of complex oxide thin film with arbitrary substrates and devices and is expected to offer a faster route towards the development of low-dimensional quantum materials.

Keywords: Freestanding, YBa₂Cu₄O₇, Pulsed laser deposition