Metrology method and apparatus, lithographic apparatus, device manufacturing method and substrate

A lithographic apparatus comprising:

• an illumination optical system arranged to illuminate a pattern;
• a projection optical system arranged to project an image of the pattern onto a substrate;
• and
• a metrology device comprising,
• an objective lens configured to direct a beam of radiation onto targets on the substrate and to collect radiation diffracted by the targets;
• a sensor configured to detect an image of the targets;
• and
• an image processor configured to identify separate images of respective ones of the targets in the image detected by the sensor,
• wherein the source, the objective lens, and the sensor are arranged so that the beam substantially simultaneously illuminates the targets and so that the image of the targets that is detected by the sensor is formed by one first order diffracted beam.

A lithographic cell comprising:

• a lithographic apparatus;
• at least one process device;
• a substrate handler;
• and
• a metrology device comprising,
• an objective lens configured to direct a beam of radiation onto targets on a substrate and to collect radiation diffracted by the targets;
• a sensor configured to detect an image of the targets;
• and
• an image processor configured to identify separate images of respective ones of the targets in the image detected by the sensor,
• wherein the source, the objective lens, and the sensor are arranged so that the beam substantially simultaneously illuminates the targets and so that the image of the targets that is detected by the sensor is formed by one first order diffracted beam.

A method comprising:

• directing an illumination beam as a measurement beam onto targets using an objective lens so that the measurement beam substantially simultaneously illuminates the targets;
• collecting radiation diffracted by the targets using the objective lens;
• detecting an image of the targets, the image being formed by only one first order diffracted beam;
• and
• identifying separate images of respective ones of the targets in the detected image.