Epitaxial growth of HfB 2(0 0 0 1) on Si(0 0 1) by etching through a SiO 2 layer

Abstract

Using the single-source chemical vapor deposition (CVD) precursor Hf(BH 4) 4, HfB 2 films can be grown epitaxially on Si substrates at 1000 °C by etching through a pre-existing SiO 2 layer. Despite the different symmetries in the plane of the interface, the film is oriented with HfB 2 (0 0 0 1)∥Si(0 0 1) and the X-ray rocking curve is exceptionally sharp, with full-width at half-maximum (FWHM)=0.076°. Top-view scanning electron microscope (SEM) micrographs show that the film consists of micrometer size domains on the substrate. X-ray pole figures and electron backscattering diffraction studies indicate the existence of four types of domains with in-plane orientations rotated 45° from each other, HfB 2[2 1 1 0]∥Si[1 0 0] and HfB 2[2 1 1 0]∥Si[1 1 0].