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HL: Fachverband Halbleiterphysik
HL 48: Heterostructures, Interfaces and Surfaces: Fabrication and Structure
HL 48.7: Vortrag
Donnerstag, 12. März 2026, 16:45–17:00, POT/0251
Nucleation behavior for remote epitaxy of GaAs and AlAs on carbon-covered GaAs substrates — •Binamra Shrestha, Tobias Henksmeier, and Dirk Reuter — Paderborn University, Paderborn, Germany
Recently, remote epitaxy was proposed as a method that enables the growth of free-standing single-crystal layers and substrate reuse by using atomically thin 2D materials as release layers. In this work, we investigate the epitaxial growth behavior of GaAs and AlAs on ultrathin amorphous carbon layers deposited by PECVD on GaAs substrates. The amorphous carbon exhibits a graphene-like structure consisting predominantly of in-plane sp2 bonding, thereby serving as a quasi-2D template capable of transmitting the substrate’s electrostatic potential for remote epitaxial growth.
We performed controlled nucleation studies using molecular beam epitaxy (MBE). First, a GaAs buffer layer is grown on the bare GaAs to planarize the substrate surface, then the sample is covered with amorphous carbon. Subsequently, ultrathin GaAs layers ranging from 0.25 nm to 2 nm are deposited on the graphene/GaAs template at 300 ∘C, and the resulting nuclei are examined via atomic force microscopy (AFM). Nucleation is first observed at approximately 0.37 nm deposition thickness, with nuclei predominantly aligned along atomic steps. This strong step-edge preference indicates that remote epitaxy is the dominant mechanism, compared to pinhole-initiated nucleation. These results highlight the suitability of PECVD-deposited amorphous carbon as an effective 2D interlayer for remote epitaxy.
Keywords: Remote epitaxy; 2-D material; Heterostructure