Special Issue Ceramics Integration. Epitaxial Growth of ZnO/AlN Heterostructures on Sapphire and Si Substrates.

Abstract

Epitaxial heterostructures of ZnO/AlN have been fabricated on both sapphire (0001) and Si (111) substrates with a 3C-SiC buffer. AlN underlayers with heterostructures were epitaxially grown by radio-frequency (RF) plasma-assisted molecular beam epitaxy (MBE). ZnO top layers were grown by direct-current (DC) sputtering using a Zn target and oxygen atmosphere. Analysis using X-ray diffraction, reflection highenergy electron diffraction (RHEED), and transmission electron microscopy (TEM) showed that both ZnO and AlN films have a monocrystalline wurtzite structure with epitaxial relationships of ZnO[0001]//AlN [0001]//sapphire[0001] and ZnO[0001]//AlN[0001]//3C-SiC[111]//Si[111] along the growth direction, ZnO[1120]//AlN[1120]//sapphire[1120] and ZnO[1120]//AlN[1120]//3C-SiC[110]//Si[110] within the growth plane, respectively. The successful growth of epitaxial ZnO/AlN films on sapphire and Si substrates demonstrates the feasibility of integrated devices consisting of these substrates.