Size-Controlled Spalling of LaAlO3/SrTiO3 Micromembranes

The ability to form freestanding oxide membranes of nanoscale thickness is of great interest for enabling material functionality and for integrating oxides in flexible electronic and photonic technologies. Recently, a route has been demonstrated for forming conducting heterostructure membranes of LaAlO₃ and SrTiO₃, the canonical system for oxide electronics. In this route, the epitaxial growth of LaAlO₃ on SrTiO₃ resulted in a strained state that relaxed by producing freestanding membranes with random sizes and locations. Here, we extend the method to enable self-formed LaAlO₃/SrTiO₃ micromembranes with control over membrane position, their lateral sizes from 2 to 20 μm, and with controlled transfer to other substrates of choice. This method opens up the possibility to study and use the two-dimensional electron gas in LaAlO₃/SrTiO₃ membranes for advanced device concepts.

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Rasmus T. Dahm, Ricci Erlandsen, Felix Trier, Alessia Sambri, Emiliano Di Gennaro, Anita Guarino, Lukas Stampfer, Dennis V. Christensen, Fabio Miletto Granozio, and Thomas S. Jespersen. Size-Controlled Spalling of LaAlO3/SrTiO3 Micromembranes, ACS Appl. Mater. Interfaces (2021). DOI: https://doi.org/10.1021/acsami.0c21612

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