Phase‐Selective CVD of Chromium Oxides from Chromyl Chloride

Phase selective chromium oxide films are deposited from chromyl chloride by CVD in the temperature range 320–380 °C. Phase selectivity is found to be driven, in part, by a templating effect of the substrate. Thin films of metastable CrO2 in (100), (001), and (110) orientations have been stabilized, respectively, by (100), (001), and (110) TiO2 single crystal substrates. In contrast, thin oriented films of the more stable Cr2O3 in (006) orientation are formed when depositing on (0001) Al2O3 single crystals over the same deposition temperature range. This phase selectivity appears to be unique to the chromyl chloride precursor.