GaN stripes on vertical {111} fin facets of (110)-oriented Si substrates

Selective sidewall epitaxy of AlN/GaN is reported on vertical fins of silicon using metallorganic vapor phase epitaxy. Silicon (110) wafers are structured to form fins with {111} sidewall facets. AlN buffer layers are grown with uniform thickness on vertical {111} surfaces, followed by GaN which grows selectively on the AlN to form the sidewall fin structures. Raman measurements of the GaN show very narrow line widths, consistent with excellent material quality. Spatial dependence from microcathodoluminescence mapping of the GaN band gap emission shows compressive strain in the GaN relaxes closer to the fin corners.