Optical closed-loop control system for a CMP apparatus and method of manufacture thereof

A method of manufacturing an optical closed-loop control system for use with a chemical mechanical polishing (CMP) apparatus for polishing a semiconductor wafer, said CMP apparatus having a platen, a polishing pad coupleable with a top surface of said platen and a wafer carrier, said method comprising:

• rigidly mounting through said platen a plurality of optical probes impacting a corresponding probe window, said probe window positioned within said polishing pad;
• coupling a flash lamp to each of said plurality of said optical probes to provide light thereto and configuring said flash lamp to minimize an exposure time of said light onto said semiconductor wafer;
• configuring a spectrograph to spatially image light received by each of said plurality of said optical probes to a common charge-coupled device (CCD) and producing real-time spectral reflectometry data therefrom;
• and
• configuring a control subsystem to analyze said real-time spectral reflectometry data and determine at least one wafer state parameter therefrom, and cause said polishing to be adjusted based upon said at least one wafer state parameter.

A method of operating an optical closed-loop control system for use with a chemical mechanical polishing (CMP) apparatus for polishing a semiconductor wafer, said CMP apparatus having a platen, a polishing pad coupleable with a top surface of said platen and a wafer carrier, said method comprising:

• employing a plurality of optical probes impacting a corresponding probe window and rigidly mountable through said platen, said probe window positioned within said polishing pad;
• providing light to each of said plurality of said optical probes employing a flash lamp and minimizing an exposure time of said light onto said semiconductor wafer;
• spatially imaging light received by each of said plurality of said optical probes to a common charge-coupled device (CCD) of a spectrograph and producing real-time spectral reflectometry data therefrom;
• and
• analyzing said real-time spectral reflectometry data, determining at least one wafer state parameter from said real-time spectral reflectometry data, and causing said polishing to be adjusted based upon said at least one wafer state parameter.

An optical closed-loop control system for use with a chemical mechanical polishing (CMP) apparatus for polishing a semiconductor wafer, said CMP apparatus having a platen, a polishing pad coupleable with a top surface of said platen, a plurality of probe windows within said polishing pad and a wafer carrier, said system comprising:

• a plurality of optical probes coupleable to corresponding ones of said plurality of probe windows and mountable through said platen;
• a flash lamp configured to provide light to each of said plurality of said optical probes;
• a spectrograph configured to spatially image light received by each of said plurality of said optical probes and produce real-time spectral reflectometry data therefrom;
• and
• a control subsystem configured to employ a n-band analysis to analyze said real-time spectral reflectometry data and determine at least one wafer state parameter therefrom, and cause said polishing to be adjusted based upon said at least one wafer state parameter.

An optical closed-loop control system for use with a chemical mechanical polishing (CMP) apparatus for polishing a semiconductor wafer, said CMP apparatus having a platen, a polishing pad coupleable with a top surface of said platen, a plurality of probe windows within said polishing pad and a wafer carrier, said system comprising:

• a plurality of optical probes coupleable to corresponding ones of said plurality of probe windows and mountable through said platen;
• a flash lamp configured to provide light to each of said plurality of said optical probes;
• a spectrograph configured to spatially image light received by each of said plurality of said optical probes and produce real-time spectral reflectometry data therefrom;
• and
• a control subsystem configured to employ a transform analysis to analyze said real-time spectral reflectometry data and determine at least one wafer state parameter therefrom, and cause said polishing to be adjusted based upon said at least one wafer state parameter.

An optical closed-loop control system for use with a chemical mechanical polishing (CMP) apparatus for polishing a semiconductor wafer, said CMP apparatus having a platen, a polishing pad coupleable with a top surface of said platen, a plurality of probe windows within said polishing pad and wafer carrier, said system comprising:

• a plurality of optical probes coupleable to corresponding ones of said plurality of probe windows and mountable through said platen;
• a flash lamp configured to provide light to each of said plurality of said optical probes;
• a spectrograph configured to spatially image light received by each of said plurality of said optical probes and produce real-time spectral reflectometry data therefrom;
• and
• a control subsystem configured to employ a metal breakthrough analysis to analyze said real-time spectral reflectometry data and determine at least one wafer state parameter therefrom, and cause said polishing to be adjusted based upon said at least one wafer state parameter.

An optical closed control system for use with a chemical mechanical polishing (CMP) apparatus for polishing a semiconductor wafer, said CMP apparatus having a platen, a polishing pad coupleable with a top surface of said platen, a plurality of probe windows within said polishing pad and a wafer carrier, said system comprising:

• a plurality of optical probes coupleable to corresponding ones of said plurality of probe windows and mountable through said platen;
• a flash lamp configured to provide light to each of said plurality of said optical probes;
• a spectrograph configured to spatially image light received by each of said plurality of said optical probes and produce real-time spectral reflectometry data therefrom;
• and
• a control subsystem configured to employ a model analysis to analyze said real-time spectral reflectometry data and determine at least one wafer state parameter therefrom, and cause said polishing to be adjusted based upon said at least one wafer state parameter.