Growth of atomically flat homoepitaxial magnesium oxide thin films by metal-organic chemical vapor deposition

Homoepitaxial magnesium oxide thin films have been grown on MgO(100), (110) and (111) substrates by the plasma enhanced metal-organic chemical vapor d eposition. Atomic force microscopy measurements indicate that the as-receiv ed MgO substrate surface morphology is greatly impro\-ed as a result of MgO homoepitaxial growth. Various oxygen partial pressures and plasma powers w ere selected to investigate the role of atomic oxygen species during the gr owth of the MgO thin films. Oxygen plasma conditions were analyzed by Langm uir probe measurements. These studies reveal that higher concentrations of atomic oxygen effectively assist the layer-by-layer growth kinetics, wt-ric h are critical to generating atomically flat surfaces. Smooth surfaces, wit h roughness as low as 0.036 nm, are achieved on MgO(100) substrates under t he conditions of 2.1 mTorr oxygen partial pressure and 1300 W plasma power at 720 degreesC. (C) 2001 Elsevier Science B.V. All rights reserved.