An aluminum oxide coating film is prepared for the first time by a solid-state conversion of boehmite (AlOOH center dot n H2O) particles, which are covalently attached on self-assembled monolayers (SAMs) of 11-mercaptoundecanoic acid (MUA) built on Au layer. The particles held on MUA SAMs are subject to sintering at elevated temperatures to fuse into monolithic film. X-ray photoelectron spectroscopy confirmed the existence of the hexacoordinate Al atoms. Fabrication steps are monitored by atomic force microscopy.