Comment by AlanYx

That same paragraph also describes ways in which it can be accomplished other than chemical etching ("...chemical etching, laser ablation, mechanical removal of material, mechanical pre-treatment followed by etching, lithography in combination with etching, and combinations thereof.").

There are also paragraphs describing applying "a plurality of inorganic dielectric layers".

Like most patents, it's hard to understand what has actually gone into production here. Could be done in a variety of ways consistent with the patent. The inorganic coatings are mentioned in claim 1, so the actual new aspect is probably the combination of etching and specific coatings.