Si-matched B x Ga1− x P grown via hybrid solid- and gas-source molecular beam epitaxy

• Published in: Applied physics letters Vol. 117; no. 12
• Main Authors: Blumer, Zak H., Boyer, Jacob T., Blumer, Ari N., Lepkowski, Daniel L., Grassman, Tyler J.
• Format: Journal Article
• Language: English
• Published: 21-09-2020
• ISSN: 0003-6951; 1077-3118
• DOI: 10.1063/5.0021493

The growth of BxGa1−xP alloys by hybrid solid/gas-source molecular beam epitaxy, with B supplied via the BCl3 gas precursor, is demonstrated. Compositional control ranging from pure GaP to B0.045Ga0.955P has thus far been achieved. Slightly tensile-strained B0.031Ga0.969P grown on nearly pseudomorphic, compressively strained GaP/Si was used to produce an effectively strain-free (0.06% tensile misfit at growth temperature) 160 nm total III–V thickness BxGa1−xP/Si virtual substrate with a threading dislocation density of <3 × 105 cm−2, at least 4× lower than comparable GaP/Si control samples. Cross-sectional transmission electron microscopy reveals that subsequent GaP overgrowth undergoes epilayer relaxation via dislocation introduction and glide at the upper GaP/B0.031Ga0.969P interface, rather than the lower GaP/Si interface, confirming the strain-balanced nature of the B0.031Ga0.969P/GaP/Si structure and its potential use as a III–V virtual substrate.