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US 6,582,978 B2Granted
Position detection mark and position detection method
AssigneeNikon Corporation
InventorNaomasa Shiraishi
Life of this patent
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Abstract
An exposure substrate includes a position detection mark having a recessed or projecting portion formed on the substrate with a difference h in depth. The difference h in depth of the recessed or projecting portion is set to (2m+1)λ/4−0.05λ≦h≦(2m+1)λ/4+0.05λ where λ is the wavelength or center wavelength,-in a photoresist, of a monochromatic or quasimonochromatic detection beam to be irradiated on the position detection mark, and m is an integer not less than 0.
Claims10
A mark detecting method of detecting a position detection mark formed on an object, comprising:
- irradiating said position detection mark with broad-band detection beams, said detection beams having a center wavelength X in the vicinity of said position detection mark, said position detection mark having a recessed or projection portion formed on said object with a difference h in level which is set to satisfy the following condition:
- (2m+1)λ/4−0.05λ≦h≦(2m+1)λ/4+0.05λ,
- wherein m is an integer not less than 0, said recessed or projecting portion of said position detection mark having asymmetry in its depth or height direction which is created in a photolithography process;
- and
- imaging said position detection mark irradiated with said detection beams to generate an output in accordance with an image of the position detection mark.
2 more elements
Dependencies are inferred from the claim text.