In a method of fabricating a metal-insulator-metal (MIM) device, initially, a first electrode is provided. An oxide layer is provided on the first electrode, and a protective layer is provided on the oxide layer. An opening through the protective layer is provided to expose a portion of the oxide layer, and a portion of the first electrode underlying the exposed portion of the oxide layer is oxidized. A second electrode is provided in contact with the exposed portion of the oxide layer. In alternative embodiments, the initially provided oxide layer may be eliminated, and spacers of insulating material may be provided in the opening.