Thru-Hole Epitaxy: Is Remote Epitaxy Really Remote?

TL;DR

This paper challenges the concept of remote epitaxy, demonstrating that what was thought to be remote is actually a nonremote thru-hole epitaxy process that is simpler and more broadly applicable.

Contribution

The study reveals that remote epitaxy is actually a form of thru-hole epitaxy, providing a straightforward method with wider applicability for epitaxial growth.

Findings

GaN domains grown through thru-holes exhibit crystallographic alignment with the substrate.

Thru-hole epitaxy is achievable even with thick, incompatible van der Waals layers or amorphous oxides.

The proposed method simplifies epitaxial growth and broadens its potential applications.

Abstract

The remote epitaxy was originally proposed to grow a film, which is not in contact but crystallographically aligned with a substrate and easily detachable due to a van der Waals material as a space layer. Here we show that the claimed remote epitaxy is more likely to be nonremote `thru-hole' epitaxy. On a substrate with thick and symmetrically incompatible van der Waals space layer or even with a three-dimensional amorphous oxide film in-between, we demonstratively grew GaN domains through thru-holes via connectedness-initiated epitaxial lateral overgrowth, not only readily detachable but also crystallographically aligned with a substrate. Our proposed nonremote thru-hole epitaxy, which is embarrassingly straightforward and undemanding, can provide wider applicability of the benefits known to be only available by the claimed remote epitaxy.