Patent ID: 6358840
Filing Date: 2002-03-19
Classification: H01L

Abstract:
A method for filling an interconnect opening to form a interconnect of an integrated circuit, said interconnect opening being within an insulating layer, the method including the steps of:A. partially filling said interconnect opening with a conductive material to form a recess within said conductive material toward a top of said interconnect opening, wherein said recess is disposed within said interconnect opening; B. depositing an alloy to fill said recess on top of said conductive material partially filling said interconnect opening; C. polishing away any conductive material and said alloy on said insulating layer such that said conductive material and said alloy are contained within said interconnect opening; D. performing a thermal anneal after said step C such that said conductive material and said alloy form into a conductive fill of a single grain structure within said interconnect opening, wherein an additional encapsulating material is formed to cover a top surface of said conductive fill during said thermal anneal from said dopant of said alloy diffusing out of said alloy and along said top surface of said conductive fill; and E. forming a bulk encapsulating layer on top of said additional encapsulating material and on top of said insulating layer; wherein said additional encapsulating material on said top surface of said conductive fill prevents lateral drift of said conductive material comprising said conductive fill along a bottom surface of said bulk encapsulating layer.