Superhydrophobic surfaces were produced on silicon substrates coated with gold, which facilitates the formation of SiO2 protrusions on the Au surface in air at low temperatures. The roughness of SiO2 increased with the oxidation period at for example, 150 degrees C. When the SiO2 surface is alkylated with dodecanol, the contact angle of water exhibited a transition from the Wenzel (complete penetration) wetting state to the Cassie (incomplete penetration) wetting state with increased roughness. It was discovered that Cassie wetting was optimized after a specific oxidation period at 150 degrees C to produce in advancing contact angle of similar to 170 degrees and a receding angle of similar to 160 degrees.