A memory device structure includes a first electrode, a second electrode, a switching layer between the first electrode and the second electrode, where the switching layer is to transition between first and second resistive states at a voltage threshold. The memory device further includes an oxygen exchange layer between the switching layer and the second electrode, where the oxygen exchange layer includes a metal and a sidewall oxide in contact with a sidewall of the oxygen exchange layer. The sidewall oxide includes the metal of the oxygen exchange layer and oxygen, and has a lateral thickness that exceed a thickness of the switching layer.