A metal-containing layer is formed on a substrate. A mask layer is formed on the metal-containing layer. The mask layer is patterned by way of a lithographically fabricated mask. The metal-containing layer is patterned with the patterned mask layer, to thereby form an electrode out of the metal-containing layer. A protective layer is deposited on the mask layer and on the substrate. The protective layer undergoes chemical mechanical polishing, during which the protective layer is removed and the electrode is uncovered.