A metal silicon oxide barrier layer between a nitride electrode containing the same metal and an oxide variable-resistance layer in a ReRAM cell prevents the metal from diffusing into the variable-resistance layer and prevents oxygen from diffusing into and oxidizing the electrode. Compound oxides of the same metal and silicon with varying stoichiometries and metal/silicon ratios may optionally replace part or all of the variable-resistance layer, a defect-reservoir layer, or both. The metal nitride electrode may include a metal silicon nitride current-limiting portion. Optionally, all the layers sharing the common metal may be formed in-situ as part of a single unit process, such as atomic layer deposition.