US 2006/0068511 A1 · CMP process metrology test structures

Abstract

A method for forming metrology structures for a CMP process is described. A trench edge is formed in a base material or stack of materials which are preferably deposited as part of the process of fabricating the production structures on the wafer. A covering film of a second material with preferably with contrasting SEM properties is deposited over the trench edge in the base material. During CMP the covering film is preferentially worn away at the edge revealing the base material. The width of the base material which has been revealed is a measure of the progress of the CMP. Since the base material and the covering material are preferably selected to have contrasting images in an SEM, a CD-SEM can be used to precisely measure the CMP progress.

Claims9

Dependent claims

A method of fabricating thin film metrology test devices on a wafer comprising the steps of:

depositing a base layer structure for a metrology test site;
forming an edge in the base layer structure by removing a selected area of the base layer structure;
depositing a covering material over the edge in the base layer structure;
performing a chemical-mechanical polishing (CMP) on the wafer;
and
measuring a width of the base layer structure exposed through the covering material as a metric of CMP progress.

3 more elements

Dependencies are inferred from the claim text.

CMP process metrology test structures

Life of this patent

CMP process metrology test structures

Life of this patent

Abstract

Claims9