Heteroepitaxial Si-ZrO2-Si by MOCVD
AbstractThe objective of this research was to demonstrate heteroepitaxial growth of yttria stabilized cubic zirconia on single crystal silicon substrates by chemical vapor deposition (CVD) using metalorganic source materials. We succeeded in depositing extremely smooth, well aligned films of zirconia on silicon substrates, both the <100> and <111> orientations, without an oxide interfacial layer. Experimental variables investigated included varying zirconia source materials, substrate temperatures, oxygen concentration, gas flow rates, yttria doping, substrate orientation, and cobalt-silicide as an oxygen diffusion barrier. ZrO2 films were predominantly tetragonal when deposited in the absence of oxygen while cubic phase material could be put down at 750°C with oxygen background. Films deposited from TMHD zirconium contained no measurable carbon contamination. Deposits from trifluoro-acetylacetonate Zr contained small amounts of fluorine, even in the presence of water vapor, and some carbon when hydrogen was used as a diluent gas.