1. A switching device, comprising: a substrate having a surface region; a first dielectric material overlying the surface region of the substrate; a bottom wiring structure overlying the first dielectric material; a first structure comprising at least a contact material overlying the bottom wiring structure and a switching material overlying the contact layer, the first structure having a top surface region substantially parallel to the surface region of the substrate, the top surface region including a top region of the switching material, wherein the switching material is configured to allow a conductive filament to form therein; a second dielectric layer overlying the first structure, wherein the second dielectric layer comprises a sidewall and an opening region exposing a first portion and a second portion of the top region of the switching material; a side wall spacer structure disposed within the sidewall of the opening region of the second dielectric layer, wherein the side wall spacer structure covers the first portion of the top surface of the switching material but not the second portion of the top surface region of the switching material, the side wall spacer structure being formed using a third dielectric material; a conductive material overlying the side wall spacer structure, the conductive material overlying and in contact with the second portion of the top surface region of the switching material but not the first portion of the top surface region of the switching material, and wherein the conductive material is a source of conductive particles for the conductive filament; and a top wiring structure overlying the conductive material.