Patent ID: 6228771
Filing Date: 2001-05-08
Classification: B24B,C09G,H01L

Abstract:
A chemical mechanical polishing process for low dishing of metal lines formed in trenches in an insulation layer of a semiconductor wafer during fabrication thereof, comprising:a first step of chemically mechanically polishing a metal layer disposed on the insulation layer and having a lower portion located in the trenches of the insulation layer for forming metal lines and an upper portion overlying the lower portion;the first step polishing being effected at a selectively high downforce sufficient to remove at a corresponding high rate the upper portion of the metal layer substantially without removing the lower portion thereof and substantially without dishing of the lower portion located in the trenches; anda second step of continuing the polishing at a selectively lower downforce sufficient to remove at a corresponding lower rate the lower portion of the metal layer with attendant minimized dishing to an extent for providing the metal lines as individual metal lines correspondingly disposed in the trenches.