Templates for LaAlO3 epitaxy on silicon

As direct epitaxy of crystalline LaAlO₃ on silicon has not been realized yet, we investigated the use of a template between the high-κ and the substrate. We performed calculations in the Density Functional Theory framework for two possible templates: a Sr_0.5O monolayer and a 0.5 nm thick γ-Al₂O₃(0 0 1) layer. We firstly found that in the Sr_0.5O monolayer case, care must be taken for the LaAlO₃ starting sequence in order to expect good band offsets with silicon. In the γ-Al₂O₃ case, a more complex engineering of the interface is needed. Nonetheless, we found stable interfaces and a surface reconstruction in agreement with experimental observations. Moreover, these interfaces exhibit insulating properties and insight calculations for a Si–γ-Al₂O₃–LaAlO₃ superstructure lead us to a 1.9 eV conduction band offset.