Stmicroelectronics Gmbh

Todd H Gandy

Robert L Hodges

Charles R Spinner, Iii

Ronald Kevin Sampson

Rebecca A Nickell

A protective barrier layer, formed of a material such as titanium or titanium nitride for which removal by chemical mechanical polishing (CMP) is primarily mechanical rather than primarily chemical, formed on a conformal tungsten layer. During subsequent CMP to pattern the tungsten layer, upper topological regions of the protective barrier layer (such as those overlying interlevel dielectric regions) are removed first, exposing the tungsten under those regions to removal, while protective barrier layer regions over lower topological regions (such as openings within the interlevel dielectric) remain to prevent chemical attack of underlying tungsten. CMP patterned tungsten is thus substantially planar with the interlevel dielectric without dishing, even in large area tungsten structures such as MOS capacitor structures.

Method for reduction in metal dishing after CMP

Barrier film deposition over metal for reduction in metal dishing after CMP

A method of forming an isolation region in an integrated circuit and an integrated circuit formed thereby. A method preferably includes forming at least one trench in a semiconductor substrate, forming an insulation layer of material in the at least one trench and on peripheral regions of the at least one trench of the semiconductor substrate, forming a sacrificial layer of material on the insulation layer having a different polishing rate than the insulation layer, and polishing the layer having the different polishing rate and portions of the insulation layer so that the sacrificial layer having the different polishing rate and portions of the insulation layer are removed, so that other portions of the insulation layer remain in the at least one trench of the substrate, and so that the upper surface of the at least one trench and the peripheral regions thereof in combination provide a substantially planar surface.

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Phoenix, AZ, United States of America

Todd H Gandy