Sacrificial stop layer and endpoint for metal CMP

A method of forming tungsten plug metallization in the fabrication of integrated circuits comprising:

• providing semiconductor device structures in and on a semiconductor substrate;
• providing an insulating layer covering said semiconductor device structures;
• depositing a sacrificial layer comprising titanium nitride overlying said insulating layer;
• etching an opening through said sacrificial layer and said insulating layer to one of said semiconductor device structures;
• depositing a titanium layer conformally over the surface of said sacrificial layer and within said opening;
• depositing a titanium nitride barrier layer overlying said titanium layer;
• depositing a tungsten layer overlying said titanium nitride barrier layer;
• and
• polishing away said tungsten layer, said titanium nitride barrier layer, and said titanium layer overlying said insulating layer wherein said sacrificial layer acts as a polish stop and an endpoint detector, wherein said sacrificial layer is completely removed, and wherein said sacrificial layer protects said insulating layer from said polishing and prevents erosion and dishing to complete said formation of said tungsten plug metallization in said fabrication of said integrated circuit.

A method of forming tungsten plug metallization in the fabrication of integrated circuits comprising:

• providing semiconductor device structures in and on a semiconductor substrate;
• providing an insulating layer covering said semiconductor device structures;
• depositing a titanium nitride sacrificial layer overlying said insulating layer;
• etching an opening through said titanium nitride sacrificial layer and said insulating layer to one of said semiconductor device structures;
• depositing a titanium layer conformally over the surface of said titanium nitride sacrificial layer and within said opening;
• depositing a titanium nitride barrier layer overlying said titanium layer;
• depositing a tungsten layer overlying said titanium nitride barrier layer;
• and
• polishing away said tungsten layer, said titanium nitride barrier layer, and said titanium layer overlying said insulating layer wherein said titanium nitride sacrificial layer acts as a polish stop and an endpoint detector, wherein said sacrificial layer is partially removed, and wherein said titanium nitride sacrificial layer protects said insulating layer from said polishing and prevents erosion and dishing to complete said formation of said tungsten plug metallization in said fabrication of said integrated circuit.