Borazine Promoted Growth of Highly Oriented Thin Films.

We report on a phenomenon, where thin films sputter-deposited on single-crystalline AlO(0001) substrates exposed to borazine─a precursor commonly used for the synthesis of hexagonal boron nitride layers─are more highly oriented than those grown on bare AlO(0001) under the same conditions. We observed this phenomenon in face-centered cubic Pd, body-centered cubic Mo, and trigonal TaC thin films grown on AlO(0001). Interestingly, intermittent exposure to borazine during the growth of TaC thin films on TaC yields better crystallinity than direct deposition of monolithic TaC. We attribute these rather unusual results to a combination of both enhanced adatom mobilities on, and epitaxial registry with, surfaces exposed to borazine during the deposition. We expect that our approach can potentially help improve the crystalline quality of thin films deposited on a variety of substrates.