Title
Silane-Mediated Expansion of Domains in Si-Doped κ-Ga2O3 Epitaxy and its Impact on the In-Plane Electronic Conduction
Author
Piero Mazzolini, Zsolt Fogarassy, Antonella Parisini, Francesco Mezzadri, David Diercks, Matteo Bosi, Luca Seravalli, Anna Sacchi, Giulia Spaggiari, Danilo Bersani, Oliver Bierwagen, Benjamin Moritz Janzen, Marcella Naomi Marggraf, Markus R. Wagner, Ildiko Cora, Béla Pécz, Abbes Tahraoui, Alessio Bosio, Carmine Borelli, Stefano Leone, Roberto Fornari
Year
2022
Journal
Advanced Functional Materials
Abstract
Unintentionally doped (001)-oriented orthorhombic κ-Ga2O3 epitaxial films on c-plane sapphire substrates are characterized by the presence of ≈ 10 nm wide columnar rotational domains that can severely inhibit in-plane electronic conduction. Comparing the in- and out-of-plane resistance on well-defined sample geometries, it is experimentally proved that the in-plane resistivity is at least ten times higher than the out-of-plane one. The introduction of silane during metal-organic vapor phase epitaxial growth not only allows for n-type Si extrinsic doping, but also results in the increase of more than one order of magnitude in the domain size (up to ≈ 300 nm) and mobility (highest µ ≈ 10 cm2V−1s−1, with corresponding lowest ρ ≈ 0.2 Ωcm). To qualitatively compare the mean domain dimension in κ-Ga2O3 epitaxial films, non-destructive experimental procedures are provided based on X-ray diffraction and Raman spectroscopy. The results of this study pave the way to significantly improved in-plane conduction in κ-Ga2O3 and its possible breakthrough in new generation electronics. The set of cross-linked experimental techniques and corresponding interpretation here proposed can apply to a wide range of material systems that suffer/benefit from domain-related functional properties.
Instrument
V-530
Keywords
Si-Doped, κ-Ga2O3