Abstract: A simple, non critical, low cost process step is added to the manufacture of integrated circuit wafers to remove a ridge of dielectric material remaining at the flat edge of the wafer after an edge rinse has removed the ridge of dielectric from the circular edges of the wafer. A layer of dielectric, such as Spin-On-Glass or the like, is formed on the wafer. An edge rinse is then used to remove the ridge of dielectric formed at the wafer edge, however the edge rinse does not remove the ridge of dielectric at the flat edge of the wafer. A layer of photoresist is formed on the wafer, selectively exposed, and developed to form a photoresist mask. The flat edge of the wafer is then dipped in buffered oxide etch to remove the dielectric material at the flat edge of the wafer. The photoresist mask is then stripped and processing of the wafer is continued.

Abstract: A method for fabricating an improved connection between active device regions in silicon, to overlying metallization levels, has been developed. A LPCVD tungsten contact plug process, which results in optimum coplanarity between the top surface of the tungsten plug and the surrounding insulator surface, has been created.

Abstract: A wafer edge seal ring structure is disclosed to provide reduced particulate contaminant generation during wafer processing of high density integrated circuits. The structure is formed by delimiting the deposition of layers at the peripheral edges of wafers. It is shown that as each layer is deposited and then essentially trimmed back from the edge of the wafer through a judicious use of mask and etching, and/or edge-bead rinsing (EBR) and later sealed by wafer edge exposure (WEE), the otherwise present abnormal growth of layers are prevented from building up into protrusions at the edge of wafer that later peel or break up to form particulate matter and fine dust. The method, which is also disclosed, teaches how each layer is recessed at appropriate distances from the wafer edge and how the whole ring structure is sealed against attacking particles.

Abstract: A process has been developed in which photoresist thinning at the edges of silicon chips, resulting from photoresist flowing from semiconductor chips, exhibiting features with raised topographies, to flat scribe regions, has been reduced. The reduction in photoresist flowing has been accomplished by creating a chessboard pattern of raised insulator and metal features, in the scribe line region, thus reducing the differences in topography between the scribe line and chip regions. The areas between the raised mesas, in the scribe line regions, are used for laser or optical endpoint detection of RIE processes.

Abstract: A tungsten stud, stacked via process, has been developed, featuring smooth planar topographies at all metal levels. The desirable topography is obtained by allowing the tungsten stud to reside at the same level, or slightly above the level, of the top surface of the via hole insulator. This is achieved via an insulator etch back procedure, performed after metal stud formation.

Abstract: This invention provides a method of preventing contact autodoping and supressing tungsten silicide peeling during the reflow cycle for a borophosphosilicate glass insulating layer during fabrication of large scale integrated circuits. The invention uses a thin oxide layer to protect the contact areas during the reflow cycle. The thin oxide layer is thin enough to allow satisfactory reflow of the borophosphosilicate glass insulating layer and thick enough to prevent autodoping and tungsten silicide peeling. The thin oxide layer is also thin enough so that process time required to remove the thin oxide layer is not a significant increase in process time. The thin oxide layer thickness is controlled by depositing a helium diluted tetraethoxysilane vapor and oxygen using chemical vapor deposition.