A method for providing a passivation layer or pH protective coating on a substrate surface by PECVD is provided, the method comprising generating a plasma from a gaseous reactant comprising polymerizing gases, for example an organosilicon precursor and optionally O2. The lubricity, passivation, pH protective, hydrophobicity, and/or barrier properties of the passivation layer or pH protective coating are set by setting the ratio of the O2 to the organosilicon precursor in the precursor feed, and/or by setting the electric power used for generating the plasma. In particular, a lubricity and/or passivation layer or pH protective coating made by said method is provided.