Surface diffusion enhancement by heterovalent doping in MOCVD of oxide films

I.E. Graboy, A.R. Kaul, I.E. Korsakov, V.V. Maleev, N.V. Markov, A.A. Molodyk

The Electrochemical Society Proceedings Volume, v. 97-25, p.925-932 (1997)

ABSTRACT. The way to improve surface smoothness and epitaxial quality of MOCVD grown oxide films by heterovalent doping and subsequent increase of point defect concentration is demonstrated. Using pulse band flash evaporation MOCVD technique epitaxial thin films of CeO2 doped with R2O3 (R = Y, Gd, Nd) were deposited on sapphire (1-102). Epitaxial quality was proved by X-ray diffraction, TEM and RBS. AFM of films surface showed that the effect of doping is very strong and comparable with effects of post deposition high temperature annealing or decrease of the deposition rate. The roughness of doped films is near independent on the growth rate in contrast to pure CeO2. Similar approach was applied to improve LaAlO3 buffer layers. The doping effect enables to obtain atomically smooth surfaces at high deposition rate.

Coordination Chemistry Laboratory