A multilayer structure of the present invention is a multilayer structure including a base substrate and a semiconductor film that is made of -Ga.sub.2O.sub.3 or an -Ga.sub.2O.sub.3-based solid solution and has a corundum crystal structure, the semiconductor film being disposed on the base substrate. The semiconductor film has an average film thickness of greater than or equal to 10 m. The semiconductor film is convexly or concavely warped. An amount of warpage of the semiconductor film is 20 m or greater and 64 m or less.

A manufacturing method of a semiconductor device includes forming a van der Waals structure between a metal and a semiconductor. The method further includes: depositing a protective layer on a two-dimensional semiconductor layer, then patterning the protective layer and the two-dimensional semiconductor layer, forming a first electrode and a second electrode on the protective layer, and removing the protective layer completely, thereby forming a van der Waals contact structure between the first electrode and the semiconductor layer and between the second electrode and the semiconductor layer.

Methods for forming structures that include forming a heteroepitaxial layer on a substrate are disclosed. The presently disclosed methods comprise epitaxially forming a buffer layer on the substrate. The substrate has a substrate composition. The buffer layer has a buffer layer composition. The buffer layer composition is substantially identical to the substrate composition. The presently disclosed methods further comprise epitaxially forming a heteroepitaxial layer on the buffer layer. The heteroepitaxial layer has a heteroepitaxial layer composition which is different from the substrate composition.