Substrate and lithography process using the same
AssigneeASML Netherlands B.V.
InventorsKeith Best, Joseph Consolini, Alexander Friz, Rodney Chisholm
Life of this patent
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Abstract
Provided are substrates, e.g. semiconductor wafers, whereby the front side of the substrate and the back side of the substrate differ in surface roughness. Also provided are lithography processes using the substrates.
Claims30
A semiconductor wafer having a front side and a back side, said front side having a smoother surface than said back side, wherein said back side comprises one or more alignment marks.
A semiconductor wafer having a front side and a back side, said front side having a surface roughness of less than 50 nm, said back side having a surface roughness in the range of 75-250 nm.
A lithography process comprising:
- (i) aligning a substrate having a front side and a back side to a reticle or an array of individually programmable elements;
- (ii) patterning a beam of radiation with said reticle or said array of individually programmable elements;
- and
- (ii) exposing the front side of said substrate, or a resist layer provided on said front side of said substrate, to the patterned beam of radiation;
- wherein said front side has a smoother surface than said back side;
- wherein said front side comprises one or more alignment marks;
- wherein said aligning is effected by imaging one or more of said one or more alignment marks via the back side of the wafer.
A process comprising providing the back side of a substrate having a front side and a back side with one or more alignment marks, wherein said front side has a smoother surface than said back side.
Dependencies are inferred from the claim text.