Thick epitaxial layers (about 2–3 µm) of crack-free zinc oxide have been obtained for the first time on a silicon substrate. A buffer layer of single-crystal silicon carbide 100 nm thick deposited by solid-phase epitaxy was used for this purpose. This results in a layer with pores and vacancies in the silicon, partially relaxing the elastic stresses. The optical constants of epitaxial layers of zinc oxide on silicon are measured. The main feature of the resulting ellipsometric spectra is light absorption in the 2.0–3.3-eV region, and this is explained by elastic stresses in the zinc oxide layer.
© 2011 OSAPDF Article