Chemical Beam Deposition of MgO Films on Si Substrates Using Methylmagnesium tert-Butoxide

Abstract

MgO films have been grown on Si(111) and Si(100) substrates at 400−800 °C by using methylmagnesium tert-butoxide as a single precursor under high-vacuum conditions (5 × 10-6 Torr). The methylmagnesium tert-butoxide precursor was synthesized and characterized by spectroscopic methods and single-crystal X-ray diffraction analysis. The chemical composition, crystalline structure, and morphology of the deposited films were investigated by X-ray photoelectron spectroscopy, X-ray diffraction, X-ray pole figure analysis, and scanning electron microscopy. The results show that epitaxial MgO films with correct stoichiometry can be deposited on Si(111) at 800 °C, whereas highly [100] oriented MgO films are deposited on Si(100) at 800 °C. Thermal desorption studies indicate that the precursor is decomposed into isobutene and methane via β-hydrogen elimination. The single precursor methylmagnesium tert-butoxide has been found suitable for chemical beam deposition of MgO thin films on Si substrates.