Method of etching back of tungsten layers on semiconductor wafers, and solution therefore

摘要

Disclosed is a method of etching back a tungsten layer on a semiconductor wafer by a polishing process. The method comprises: exposing the wafer to be polished to a polishing solution at a preselected temperature, the polishing solution comprising an oxidizing component which oxidizes tungsten on the wafer to tungsten oxide; mechanically polishing the tungsten oxide from the wafer and into the polishing solution; and the polishing solution also comprising a dissolution component selected from the group consisting of KOH and NH4OH or a mixture thereof, the tungsten oxide being substantially dissoluted by the dissolution component in the solution.