Wurtzite III–Nitride Distributed Bragg Reflectors on Si(100) Substrates

Distributed Bragg reflectors (DBRs) composed of an AlN/GaN superlattice were demonstrated for the first time on Si(100) substrates. Single-crystal wurtzite superlattice structures were achieved on this cubic substrate by employing offcut Si(100) wafers with the surface normal pointing 4° towards the [110] direction. This misorientation introduced an additional epitaxial constraint that prevented the growth of a two-domain GaN surface as well as cubic GaN inclusions. A crack-free 600 nm GaN cap/5×AlN/GaN DBR structure on Si(100) was demonstrated. This accomplishment of a wurtzite III–nitride DBRs on Si(100) opens the possibility to integrate novel optical and optoelectronic devices with established Si microelectronics technology.