Synthesis of metastable epitaxial zinc-blende-structure AlN by solid-state reaction

Abstract

Epitaxial metastable zinc‐blende‐structure β‐AlN was synthesized by the solid‐state reaction between single‐crystal Al(001) and TiN(001) layers grown on MgO(001) by ultrahigh vacuum magnetron sputter deposition. At an annealing temperature T_a=600 °C, the interaction proceeded according to the following overall reaction: 4Al+TiN→Al₃Ti+AlN, in which β‐AlN was formed pseudomorphically between cubic TiN and tetragonal Al₃Ti layers. The lattice constant of β‐AlN was found to be 0.438 nm, which corresponds to a 3.3% lattice mismatch with the underlying TiN layer.