Regensburg 2022 – scientific programme

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HL: Fachverband Halbleiterphysik

HL 42: 2D Materials 6 (joint session HL/CPP/DS)

HL 42.6: Talk

Friday, September 9, 2022, 11:00–11:15, H36

Selective area growth of MoS₂ via CVD on patterned GaN-AlO_x substrates — •Simon Wörle, Theresa Grünleitner, Alex Henning, and Ian Sharp — Walter Schottky Institute and Physics Department, Technical University of Munich, Garching, Germany

Two-dimensional (2D) transition metal dichalcogenides have attracted considerable attention due to their unique optoelectronic properties. For the application of 2D materials in semiconductor devices, the controlled and scalable synthesis of high-quality 2D materials is critical.

Here, we demonstrate the selective area growth of MoS₂ by chemical vapor deposition (CVD) on GaN substrates that were patterned with ultrathin aluminum oxide coatings created by low-temperature atomic layer deposition. Optical and scanning electron microscopy images show that mono- and few-layer MoS₂ flakes preferentially nucleate and grow directly on the (uncoated) GaN. Atomic force microscopy and Raman measurements further reveal the formation of triangular and star-like shaped multilayer MoS₂ crystals at the interfaces between GaN and AlO_x. Moreover, the observed fixed orientation of the triangular MoS₂ flakes with respect to the GaN substrate lattice indicates van der Waals epitaxy. By altering the CVD growth conditions, the density of deposited MoS₂ flakes can be tuned, resulting in the growth of either isolated MoS₂ nanosheets or continuous films, in the latter of which the individual flakes have coalesced.

The presented results mark an important step towards integrated MoS₂ based heterostructures for semiconductor device applications.