CVD of ZrO2, Al2O3 and Y2O3 from metalorganic compounds in different reactors

The deposition of ZrO2, Y2O3 or Al2O3 from the precursors Zr(tmhd)(4), Y(tmhd)(3) and Al(acac)(3) is investigated in this paper. Chemical vapor deposition (CVD) experiments were carried out in the temperature range 500-1100 K at pressures between 1000 and 4000 Pa in different reactors with different temperature fields. In addition. the temperature gradient between substrate and gas was changed from negative to positive values in order to measure the influence of thermophoresis effects. The deposition rate j in the low temperature range can be described by an Arrhenius law, j=k exp(-E/RT), whereby the pre-exponential factor k and the activation energy E depend on the temperature field. It is experimentally found that the effect of a changing activation energy is partly compensated by a changing pre-exponential factor in the same direction (compensation effect). In the case of Al2O3-deposition, thermophoresis effects were measured. (C) 2000 Elsevier Science S.A. All rights reserved.