Interface-based thin film metrology using second harmonic generation

A metrology system, comprising:

• a controller including one or more processors configured to execute program instructions causing the one or more processors to:
• receive metrology data from a detector associated with second harmonic generation (SHG) light from a sample in response to an illumination beam, wherein the sample includes an inversion-symmetric substrate and one or more films disposed on the inversion-symmetric substrate;
• and
• generate one or more metrology measurements associated with the one or more films based on the SHG light associated with an interface between the inversion-symmetric substrate and the one or more films.

A metrology method, comprising:

• directing an illumination beam at a sample, wherein the sample includes an inversion-symmetric substrate and one or more films disposed on the inversion-symmetric substrate;
• capturing metrology data based on second harmonic generation (SHG) light from the sample associated with an interface between the inversion-symmetric substrate and the one or more films;
• and
• generating one or more metrology measurements associated with the one or more films based on the metrology data.