Target for measuring a parameter of a lithographic process
AssigneeASML Netherlands B.V.
InventorsMaurits VAN DER SCHAAR, Olger Victor ZWIER, Patrick WARNAAR
Life of this patent
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Abstract
A target for determining a performance parameter of a lithographic process, the target comprising a first sub-target formed by at least two overlapping gratings, wherein the underlying grating of the first sub-target has a first pitch and the top lying grating of the first sub-target has a second pitch, at least a second sub-target formed by at least two overlapping gratings, wherein the underlying grating of the second sub-target has a third pitch and the top lying grating of the second sub-target has a fourth pitch.
Claims20
A target for determining a performance parameter of a lithographic process, the target comprising:
- a first sub-target formed by at least two overlapping gratings, wherein an underlying grating of the first sub-target has a first pitch and a top lying grating of the first sub-target has a second pitch;
- and
- at least a second sub-target formed by at least two overlapping gratings, wherein an underlying grating of the second sub-target has a third pitch and a top lying grating of the second sub-target has a fourth pitch.
A method of making a target for determining a performance parameter of a lithographic process, comprising:
- forming a first sub-target having at least two overlapping gratings, wherein an underlying grating of the first sub-target has a first pitch and a top lying grating of the first sub-target has a second pitch;
- and
- forming at least a second sub-target having at least two overlapping gratings, wherein an underlying grating of the second sub-target has a third pitch and a top lying grating of the second sub-target has a fourth pitch.
Dependencies are inferred from the claim text.