Abstract: A process has been developed which allows contact between levels of interconnect metallization structures, to occur without the use of via holes, etched in interlevel insulator layers. The process features creation of a raised tungsten plug structure, used to provide contact between underlying active device regions and an overlying interconnect metallization structure. The tungsten plug structure is formed by photolithographic masking and dry etching procedures, thus avoiding increasing the size of a tungsten seam, in the center of the plug structure. In addition the tungsten definition process, also results in a raised plug structure, allowing subsequent contact of interconnect metallization levels to proceed without the use of etched via holes in interlevel insulator layers.

Abstract: A process for creating narrow, metal via structures, used to connect metallization levels, has been developed. The process features initially forming a narrow, metal via structure, and then an underlying interconnect metallization structure, from a single, composite metallization layer. The composite metallization layer is composed of conductive layers, with a specific layer used as an etch stop, allowing creation of a narrow metal via structure, from the top layer of the composite metallization layer, without disturbing the bottom layers. The bottom layers of the composite metallization layer are then patterned to create the underlying interconnect metallization structure.