Semiconductor devices having amorphous silicon antifuse structures

An integrated circuit device, comprising:

• a substrate having a plurality of active regions, a plurality of dummy diffusion regions and a plurality of field oxide regions that are raised relative to the active and dummy diffusion regions;
• a first dielectric layer positioned over the substrate such that the first dielectric layer has topographically lower regions over the plurality of active regions and dummy diffusion regions and topographically higher regions over the field oxide regions;
• a first metallization layer defining a network of metallization lines, at least some of the metallization lines being arranged to electrically interconnect preselected ones of the plurality of active regions, wherein at least some of the metallization lines pass over associated field oxide regions;
• an antifuse positioned over the first dielectric layer such that the antifuse is positioned over an associated dummy diffusion region and not over the field oxide regions, the antifuse includes,
• a portion of the first metallization layer that is positioned over the first dielectric layer, and an intermediate dielectric layer covering a segment of the first metallization layer such that a via-link opening is provided in the intermediate dielectric to provide an electrical path with the portion of the first metallization layer;
• an amorphous silicon layer formed over the intermediate dielectric layer such that the amorphous silicon layer makes direct contact with the first metallization layer through the via-link opening in the intermediate dielectric;
• and
• a barrier layer formed over the amorphous silicon layer, and a second dielectric layer positioned over the first dielectric layer and the first metallization layer, the second dielectric layer having a multiplicity of via holes, wherein at least some of the via holes are positioned to communicate with segments of the metallization layer and one of the via holes is positioned to communicate with the antifuse.