Phase‐Selective CVD of Chromium Oxides from Chromyl Chloride

Abstract

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 CrO 2 in (100), (001), and (110) orientations have been stabilized, respectively, by (100), (001), and (110) TiO 2 single crystal substrates. In contrast, thin oriented films of the more stable Cr 2 O 3 in (006) orientation are formed when depositing on (0001) Al 2 O 3 single crystals over the same deposition temperature range. This phase selectivity appears to be unique to the chromyl chloride precursor.