Method for polishing cobalt-containing substrate

The invention is a method for chemical mechanical polishing a semiconductor substrate having cobalt or cobalt alloy containing features containing Co0. The method mixes 0.1 to 2 wt % hydrogen peroxide oxidizing agent (α) into a slurry containing 0.5 to 3 wt % colloidal silica particles (β), the coll...

Ausführliche Beschreibung

Gespeichert in:
Bibliographische Detailangaben
Hauptverfasser: Wang, Hongyu, Theivanayagam, Murali G
Format: Patent
Sprache:eng
Schlagworte:
Online-Zugang:Volltext bestellen
Tags: Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
Beschreibung
Zusammenfassung:The invention is a method for chemical mechanical polishing a semiconductor substrate having cobalt or cobalt alloy containing features containing Co0. The method mixes 0.1 to 2 wt % hydrogen peroxide oxidizing agent (α) into a slurry containing 0.5 to 3 wt % colloidal silica particles (β), the colloidal silica particles containing primary particles, 0.5 to 2 wt % complexing agent (γ) selected from at least one of L-aspartic acid, nitrilotriacetic acid, nitrilotri(methylphosphonic acid), ethylenediamine-N,N′-disuccinic acid trisodium salt, and ethylene glycol-bis (2aminoethylether)-N,N,N′,N′-tetraacetic acid, and balance water having a pH of 5 to 9 to create a polishing slurry for the semiconductor substrate. Oxidizing at least a surface portion of the Co0 to Co+3 of the semiconductor substrate to prevent runaway dissolution of the Co0 reduces polishing defects in the semiconductor substrate. Polishing the semiconductor substrate with a polishing pad removes the surface portion of the semiconductor substrate oxidized to Co+3.