ZnO has the potential to become the substrate material of choice for GaN. Like GaN, ZnO has a wurtzite structure, with lattice constants closely matched to GaN (a=3.249, c=5.205). ZnO is exactly lattice matched to InGaN with a 22% In content. ZnO is a soft compliant material that is believed to probably and may take up the lattice stress in preference to the growing GaN layer. ZnO dissociates in ammonia at temperatures above 600 deg.C. With its wide bandgap, Zinc Oxide could prove very useful in optical applications as well as many high speed electronics. ZnO may also be used as a substrate for epitaxial growth.
