MOCVD of MgAl2O4 thin films using new single molecular precursors:: application of β-hydrogen elimination to the growth of heterometallic oxide films

We have deposited the MgAl2O4 thin films on Si(1 0 0) substrates in the temperature range of 270 similar to 600 degreesC using newly developed single molecular precursors of Mg[(mu -O'Bu)(2)AlMe2](2) and Mg[Al(O'Bu)(4)](2) by MOCVD. Polycrystalline, crack-free stoichiometric MgAl2O4 thin films were successfully grown on at as low as 400 degreesC. This growth temperature was much lower than that of conventional CVD, and this is the first report of the MgAl2O3 growth using Mg[(mu -O'Bu)(2)AlMe2](2). During film deposition, the vapor pressure of Mg[Al(O'Bu)(4)](2) was decreased due to oligomerization of the precursor itself. When Mg[(mu O'Bu)(2)AlMe2](2) was used, however, the vapor transport problem of the precursor was solved by introducing more volatile alkyl group. beta -Hydrogen elimination was employed in the growth mechanism. The synthesized precursors and the as-grown films were characterized with NMR, XRD, XPS, RES, and SEM, and the gas-phase by-products of the CVD reaction were collected and identified by gas chromatography. (C) 2001 Elsevier Science B.V. All rights reserved.