Feature Transformer Architecture For Advanced Semiconductor Metrology

A method comprising:

• illuminating a semiconductor structure disposed on a semiconductor wafer under measurement with a beam of illumination radiation, the semiconductor structure under measurement including a plurality of structural features;
• detecting radiation from the semiconductor structure under measurement in response to the beam of illumination radiation;
• generating a set of actual measurement signals indicative of the detected radiation;
• determining one or more measurement signal combinations from the actual measurement signals;
• and
• estimating a first value of a parameter of interest characterizing the structure under measurement based on the one of more measurement signal combinations.

A metrology system comprising:

• an illumination source configured to generate a beam of radiation incident on a semiconductor structure disposed on a semiconductor wafer under measurement, the semiconductor structure under measurement including a plurality of structural features;
• a detector configured to detect radiation from the semiconductor structure under measurement in response to the incident beam of radiation and generate a set of actual measurement signals indicative of the detected radiation;
• and
• a non-transitory, computer-readable medium comprising instructions that when executed by one or more processors causes the one or more processors to:
• determine one or more measurement signal combinations from the actual measurement signals;
• and
• estimate a first value of a parameter of interest characterizing the structure under measurement based on the one of more measurement signal combinations.