Method for fabrication of a CEM device

Disclosed is a method for the fabrication of a correlated electron material (CEM) switching device, the method comprising: forming a layer of a conductive substrate; forming a layer of a correlated electron material on the conductive substrate; forming a layer of a conductive overlay on the layer of correlated electron material; and patterning the layers whereby to form a stack comprising a conductive substrate, a CEM layer and a conductive overlay, wherein the patterning comprises the following steps: forming a hard mask on the layer of the conductive overlay; dry etching the layer of conductive overlay and the layer of correlated electron material whereby to form a partially formed stack; depositing a coating of a protective polymer over at least sidewalls of the partially formed stack; and dry etching the layer of conductive substrate.