Systems and methods for characterizing a polishing process

A method for characterizing polishing of a specimen, comprising:

• scanning the specimen with two or more measurement devices during said polishing to generate output signals at measurement spots across the specimen, wherein the two or more measurement devices comprise an optical device and an eddy current device;
• determining a characteristic of a polishing pad used for said polishing from the output signals;
• and
• determining a characteristic of said polishing from the output signals.

A method for characterizing polishing of a specimen, comprising:

• scanning the specimen with a measurement device during said polishing to generate output signals at measurement spots across the specimen, wherein the measurement device comprises a laser light source coupled to a first fiber optic bundle and a detector coupled to a second fiber optic bundle;
• and
• determining a characteristic of said polishing from the output signals;
• and
• combining a portion of the output signals generated at the measurement spots located within a zone on the specimen, wherein said determining comprises determining the characteristic of said polishing within the zone from the combined portion of the output signals.

A method for characterizing polishing of a specimen, comprising:

• scanning the specimen with a first measurement device during a first step of the polishing to generate output signals at measurement spots across the specimen;
• generating a first portion of a signature from the output signals;
• scanning the specimen with a second measurement device during a second step of the polishing to generate additional output signals at the measurement spots;
• and
• generating a second portion of the signature from the additional output signals.

A system configured to characterize a polishing process, comprising:

• a first measurement device configured to scan a specimen during a first step of the polishing process to generate output signals at measurement spots across the specimen;
• a processor coupled to the first measurement device, wherein the processor is configured to generate a first portion of a signature from the output signals;
• a second measurement device configured to scan the specimen during a second step of the polishing process to generate additional output signals at the measurement spots;
• and
• wherein the processor is further coupled to the second measurement device, and wherein the processor is further configured to generate a second portion of the signature from the additional output signals.

A method for characterizing polishing of a specimen, comprising:

• scanning the specimen with an eddy current device during said polishing to generate output signals at measurement spots on the specimen;
• performing said scanning until a predetermined thickness of a film is detected on the specimen from the output signals, wherein the predetermined thickness is less than about 200 nm;
• scanning the specimen with an optical device subsequent to detecting the predetermined thickness to generate additional output signals at the measurement spots on the specimen;
• and
• determining a characteristic of said polishing from the output signals and the additional output signals.