Boehmite thin film with 50-100 nm surface flake structure has been synthesized on AISI 316 type austenitic stainless steel by immersing boehmite gel film into boiling water. When further coated with hydrolyzed (heptadecafluoro-1,1,2,2-tetrahydrodecyl) trimethoxysilane (FAS), the boehmite film becomes superhydrophobic with a contact angle for water of 152 degrees. The superhydrophobic property results from both the nanoscale surface flake structure and the low surface energy of the FAS top layer. The topography of such film was revealed by atomic force microscope (AFM) and a set of roughness parameters of such film was discussed. The degradation of superhydrophobicity of the surface was studied as a function of the heat-treatment temperatures. Below 600 degrees C, the surface remained to be superhydrophobic with the FAS top layer. Above 700 degrees C, the surface was not superhydrophobic anymore due to a gradual loss in surface roughness which was revealed by field emission scanning electron microscope (FESEM). A phase change from boehmite to gamma-Al2O3 occurred during the heat-treatments from 700 to 900 degrees C which was studied by the selected area electron diffraction (SAED) patterns from the transmission electron microscope (TEM) measurement. (C) 2008 Elsevier B.V. All rights reserved.