Inspection method and apparatus, lithographic apparatus, lithographic processing cell and device manufacturing method
AssigneeASML Netherlands B.V.
InventorsWolfgang Max Adolf Bernhard Osten, Karsten Frenner, Bartosz Jan Bilski
Life of this patent
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Abstract
Determining line edge roughness comprises reflecting at least one radiation beam off the object, observing a first optical response signature from a beam reflected from the object, or a component thereof, being polarized with an electrical vector in a first orientation relative to the object; and observing a second optical response signature from a beam reflected from the object, or a component thereof, being polarized with an electrical vector in a second orientation relative to the object. Line edge roughness can then be determined from the two optical response signatures.
Claims18
A method comprising:
- obtaining a first optical response signature from a first radiation beam reflected from an object, the first radiation beam being polarized with a first electrical vector in a first orientation relative to the object;
- obtaining a second optical response signature from a second radiation beam reflected from the object, the second radiation beam being polarized with a second electrical vector in a second orientation relative to the object;
- determining a first effective critical dimension (ECD) and a second ECD of the object based on the first and second optical response signatures, respectively;
- and
- determining a parameter related to edge roughness of the object based on the first ECD and the second ECD.
An inspection apparatus comprising:
- a controller configured to:
- reflect a radiation beam off an object;
- obtain a first optical response signature from the radiation beam reflected from the object, the radiation beam being polarized with a first electrical vector in a first orientation relative to the object;
- obtain a second optical response signature from the radiation beam reflected from the object, the radiation beam being polarized with a second electrical vector in a second orientation relative to the object;
- determine a first effective critical dimension (ECD) and a second ECD of the object based on the first and second optical response signatures, respectively;
- and
- determine a parameter related to edge roughness of the object based on the first ECD and the second ECD.
A non-transitory computer-readable storage device having instructions stored thereon, execution of which, by a computing device, causes the computing device to perform operations comprising:
- obtaining a first optical response signature from a radiation beam reflected from the object, the radiation beam being polarized with a first electrical vector in a first orientation relative to the object;
- obtaining a second optical response signature from the radiation beam reflected from the object, the radiation beam being polarized with a second electrical vector in a second orientation relative to the object;
- determining a first effective critical dimension (ECD) and a second ECD of the object based on the first and second optical response signatures, respectively;
- and
- determining a parameter related to edge roughness of the object based on the first ECD and the second ECD.
Dependencies are inferred from the claim text.