Patent US 5,374,832

An antifuse (42) is formed by forming a layer of titanium tungsten (34) overlying a portion of a first metal layer (28). The titanium tungsten layer (34) is oxidized to form a film of oxide (36) on its surface. Insulating regions (30) are formed adjacent the titanium tungsten layer (34) and overlying the first metal layer (28). A second metal layer (40) is formed overlying the titanium tungsten layer (34). Applying a break down voltage across the first and second metal layers (28), (40) will break down the oxide film (36), thereby causing a connection between the first and second metal layers (28), (40).