Deposition of zinc oxide thin films by combustion CVD

Combustion chemical vapor deposition (combustion CVD) has been developed to produce zinc oxide thin films. Combustion CVD is different from convention al CVD in that it is performed in a flame. The flame provides the energy, p rimarily in the form of heat, necessary to deposit ceramic thin films. Zinc 2-ethylhexanoate was dissolved in an organic solvent to produce the flamma ble solutions used to deposit zinc oxide films onto amorphous silica substr ates. Zinc ion concentrations in the solutions were 0.01 M. Substrate tempe ratures were monitored and controlled during the depositions. Several subst rate temperatures, ranging from 190-850 degrees C, were used. Crystalline f ilms up to 1.4 mu m-thick were produced at deposition rates up to 5 mu m/h. The films were of the hexagonal wurtzite structure and displayed a strong preferred orientation of (002) normal to the substrate surfaces. A variety of microstructures were produced depending on substrate temperature during deposition. Scanning electron microscopy, transmission electron microscopy, X-ray diffraction and Rutherford backscattering spectrometry were used to characterize the films. (C) 1999 Published by Elsevier Science S.A. All rig hts reserved.