Memory devices and methods for manufacturing are described herein. A memory device as described herein includes a first electrode layer, a second electrode layer, and a thermal isolation structure including a layer of thermal isolation material between the first and second electrode layers. The first and second electrode layers and the thermal isolation structure define a multi-layer stack having a sidewall. A sidewall conductor layer including a sidewall conductor material is on the sidewall of the multi-layer stack. The sidewall conductor material has an electrical conductivity greater than that of the thermal isolation material. A memory element including memory material is on and in contact with the second electrode layer.