Faceted growth of ({\bf {\overline 1}103})-oriented GaN domains on an SiO2-patterned m-plane sapphire substrate using polarity inversion

Abstract

Heteroepitaxial growth of ({\overline 1}103)-oriented GaN domains on m-plane sapphire is energetically unfavourable in comparison with that of (1{\overline 1}0{\overline 3})-oriented GaN domains, but the faceted domains with ({\overline 1}103)-oriented GaN reveal a more m-facet-dominant configuration than (1{\overline 1}0{\overline 3})-oriented GaN in such a way that the quantum-confined Stark effect can be more effectively suppressed. It is reported here, for the first time, that semipolar ({\overline 1}103)-oriented and faceted GaN domains can be grown on an SiO2-patterned m-plane sapphire substrate by employing polarity inversion of initially nucleated (1{\overline 1}0{\overline 3})-oriented GaN domains. This polarity inversion of semipolar GaN was found to occur when the domains were grown with a 20–37.5 times higher V/III ratio and 70 K lower growth temperature than corresponding parameters for polarity-not-inverted domains. This work opens up a new possibility of effective suppression of the quantum-confined Stark effect by polarity-controlled semipolar GaN in an inexpensive manner in comparison with homoepitaxial growth of ({\overline 1}103)-oriented GaN on a GaN substrate.