HETEROEPITAXIAL GROWTH OF INN ON ALN-NUCLEATED (00.1) SAPPHIRE BY ULTRAHIGH-VACUUM ELECTRON-CYCLOTRON RESONANCE-ASSISTED REACTIVE MAGNETRONSPUTTERING

A novel deposition technique, ultrahigh vacuum electron cyclotron reso nance (ECR)-assisted reactive magnetron sputtering, has been developed for the preparation of group IIIA nitride thin films. In initial expe riments, thin films of the semiconductor InN have been deposited on Al N-seeded (00.1) sapphire substrates, and the properties of these films studied as a function of growth temperature. Comparison to InN thin f ilms grown by conventional reactive magnetron sputtering shows enhance d Hall mobilities (from about 50 to over 80 cm2/V s), a decreased carr ier concentration (by about a factor of 2), an increased optical band gap, and an apparent reduction in homogeneous strain that is in part d ue to film relaxation induced by the ECR beam and in part to enhanced nitrogen content and more nearly stoichiometric films.