Multilevel interconnect planarization by voltage and laser programmable links using ion implantation

A technique is described whereby implantation of silicon through a mask into the intermetal insulator modifies the insulation. After deposition and definition of the upper metal, the implanted regions between metal levels act as voltage programmable links. Application of a voltage between upper and lower metal electrodes causes the implanted insulation to become conductive, producing a low-resistance, planar, vertical connection. Alternatively, these implanted areas can be rendered conducting by exposure to a focused laser beam