1. An integrated circuit, comprising: a first layer formed into a device, subject to alteration in electronic properties of the device caused by a change in concentration of at least one type of atom at an active switching junction of the device; a second layer formed parallel to the first layer, having the at least one type of atom diffused therein in sufficient concentration to alter the device properties if in direct contact with the first layer, configured to provide a selectively formed electronic path for electrical communication with the first layer; and a diffusion barrier layer interposed between the first and second layers, formed from a composition which provides a non-switching conducting path between the first and second layers, and which substantially blocks diffusion of the at least one type of atom from the second layer to the first layer, such that the properties of the first layer remain stable after fabrication and storage, the diffusion barrier layer being patterned together with the first layer in a common photolithographic mask step.