Sensor apparatus for lithographic measurements
AssigneeASML Netherlands B.V.
InventorAlessandro Polo
Life of this patent
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Abstract
A sensor apparatus comprising an acoustic assembly arranged to transmit an acoustic signal to a substrate and receive at least part of the acoustic signal after the acoustic signal has interacted with the substrate, a transducer arranged to convert the at least part of the acoustic signal to an electronic signal, and, a processor configured to receive the electronic signal and determine both a topography of at least part of the substrate and a position of a target of the substrate based on the electronic signal. The sensor apparatus may for part of a lithographic apparatus or a metrology apparatus.
Claims19
A sensor apparatus comprising:
- an acoustic assembly arranged to transmit an acoustic signal to a substrate having a buried target, and arranged to receive at least part of a reflected acoustic signal after the acoustic signal has interacted with the substrate;
- a transducer arranged to convert the at least part of the reflected acoustic signal to an electronic signal;
- and
- a processor configured to:
- receive the electronic signal,
- determine both a topography of at least part of the substrate and a position of the buried target based on the electronic signal, and
- at least partially account for the topography of the at least part of the substrate when determining the position of the buried target of the substrate.
A method of measuring both a topography of at least part of a substrate and a position of a buried target of the substrate, the method comprising:
- directing an acoustic signal at the substrate;
- receiving at least part of the acoustic signal after the acoustic signal has interacted with the substrate;
- and
- determining both the topography of at least part of the substrate and the position of the buried target of the substrate based on the at least part of the acoustic signal, the determining at least partially accounting for the topography of the at least part of the substrate when determining the position of the buried target of the substrate.
Dependencies are inferred from the claim text.