Technology Integration

Today's computer chips use very dense arrays of logic transistors interconnected by up to 7 layers of metal tracks. Two key features of this technology are the introduction of barrier layers that allow good conductors such as copper (or silver) to be used. These metal layers also have to be coupled selectively using metal plugs which fill small vias (or pores) in the inter-metal dielectric layers. By substituting an amorphous layer for a metal plug, we create a PMCm or a selectively switchable connection between metal layers. This can either be used to configure the logic configuration or as part of a local memory array where the transistors in the underlying silicon provide the drive and sense circuitry. By making a very small change in the total chip fabrication process, PMCm technology minimizes its cost and leverages the rapid advances that have been made in mainstream silicon processing but at the same time offering radically new system solution possibilities.