Method of making heat treated coated article using carbon based coating and protective film

A method of making a heat treated coated article, the method comprising:

• heat treating a coated glass substrate, the coated glass substrate comprising, prior to the heat treating, a glass substrate, a layer comprising carbon on the glass substrate, and a protective film on the glass substrate over at least the layer comprising carbon, wherein the protective film includes a release layer and an oxygen barrier layer, wherein the release layer comprises zinc oxynitride ZnOxNz and where at least one of:
• (i) a nitrogen to oxygen ratio z/x in the release layer is at least 0.40, and/or (ii) a ratio of nitrogen gas to oxygen gas during sputtering in an atmosphere in which the release layer is sputter-deposited is from 0.55 to 0.77:
• during said heat treating of the coated glass substrate with the layer comprising carbon and the protective film thereon, the protective film prevents significant burnoff of the layer comprising carbon, and wherein the heat treating comprises heating the glass substrate to temperature(s) sufficient for thermal tempering, heat strengthening, and/or heat bending;
• and
• removing at least part of the protective film during and/or after said heat treating.