Optically-based method and apparatus for detecting and characterizing surface pits in a metal film during chemical mechanical polish

An optically-based metrology system comprising means for generating pump and probe pulse pairs that are directed to a surface of a film layer disposed over a substrate, a detector for detecting reflected probe pulses, and a processor having an input coupled to an output of said detector for detecting a presence of a surface pit in the film layer by an examination of the pulse shape of the reflected probe pulses, where the resulting pulse shape is characterized by a double peak.

An optically-based metrology system having an output for indicating an occurrence of a failure in a chemical mechanical polish process performed on a metal film, comprising means for generating pump and probe pulse pairs that are directed to a surface of the metal film, a detector for detecting reflected probe pulses, and a processor having an input coupled to an output of said detector for detecting a presence of a surface pit in the metal film by an examination of the pulse shape of the reflected probe pulses, where the pulse shape is characterized by a double peak.

An optically-based metrology system for providing a quality indication to a chemical mechanical polish (CMP) process, said system having an output coupled to the CMP process for indicating an occurrence of a defect in a metal film, comprising means for generating pump and probe pulse pairs that are directed to a surface of the metal film, a detector for detecting reflected probe pulses, and a processor having an input coupled to an output of said detector for detecting a presence of a surface pit in the metal film by an examination of the pulse shape of the reflected probe pulses, where the pulse shape is characterized by a double peak and is indicative of a metal film defect.

A method for operating a metrology system, comprising:

• generating pump and probe pulse pairs that are directed to a surface of a metal film, detecting reflected probe pulses, and examining the pulse shape of the reflected probe pulses for detecting a presence of a surface pit in the metal film.

A method for operating a metrology system, comprising:

• generating pump and probe pulse pairs that are directed to a surface of a metal film, detecting reflected probe pulses, and examining the pulse shape of the reflected probe pulses for detecting a presence of a surface pit in the metal film, where the pulse shape is characterized by a double peak.

A method for indicating an occurrence of a failure in a chemical mechanical polish process performed on a metal film, comprising:

• generating pump and probe pulse pairs that are directed to a surface of the metal film, detecting reflected probe pulses, and examining the pulse shape of the reflected probe pulses for detecting a presence of a surface pit in the metal film, where the pulse shape is characterized by a double peak.

A method for providing a quality indication to a chemical mechanical polish (CMP) process, the quality indication comprising an occurrence of a defect in a metal film, comprising:

• generating pump and probe pulse pairs that are directed to a surface of the metal film, detecting reflected probe pulses, and detecting a presence of a surface pit in the metal film by an examination of the pulse shape of the reflected probe pulses, where the pulse shape is characterized by a double peak and is indicative of a metal film defect.

A metrology system comprising at least one light source to generate pump pulses and probe pulses directed towards a surface of a sample, a light detector positioned to convert probe pulses that impinge on the surface of the sample to electrical signal pulses at an output of said light detector, and a data processor having an input coupled to said output of said light detector, said data processor operating in accordance with a stored program to detect a presence of a pit in the surface of the sample through an examination of the shape of the electrical signal pulses.

A metrology system comprising at least one light source to generate pump pulses and probe pulses directed towards a surface of a sample, a light detector positioned to convert probe pulses that impinge on the surface of the sample to electrical signal pulses at an output of said light detector, and a data processor having an input coupled to said output of said light detector, said data processor operating in accordance with a stored program to detect a presence of a pit in the surface of the sample through an examination of the shape of the electrical signal pulses, where the data processor detects the presence of the pit in the surface when the examination finds two peaks in the shape of the electrical signal pulses.

A memory, said memory for being readably coupled to a data processor that forms a part of a metrology system that generates electrical signal pulses from light pulses that impinge on a surface of a sample, said data processor operating in accordance with a stored program to detect a presence of a pit in the surface of the sample through an examination of the shape of the electrical signal pulses, said memory storing a set of pulse shape templates that said data processor compares to the shape of the electrical signal pulses, said data processor operating in accordance with the stored program to detect a presence of a pit in the surface when the shape of the electrical signal pulses matches a pulse shape template characterized as having two peaks.