Direct phase shift measurement between interference patterns using aerial image measurement tool
AssigneeInternational Business Machines Corporation
InventorsMichael Straight Hibbs, Song Peng
Life of this patent
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Abstract
A method of measuring the phase shift between two regions of a phase shift mask. A workpiece is provided including a first pair of slits each having a substantially similar phase shift characteristic and a second pair of slits each having a different phase shift characteristic. Electromagnetic radiation is directed through the first pair of slits and the second pair of slits on the workpiece. A relative shift is measured between interference patterns caused by the first pair of slits and the second pair of slits.
Claims26
A method of measuring the phase shift between two regions of a phase shift mask, said method comprising the steps of:
- providing a workpiece including a first pair of slits each having a substantially similar phase shift characteristic and a second pair of slits each of said second pair of slits having a different phase shift characteristic;
- directing electromagnetic radiation through said first pair of slits and said second pair of slits on said workpiece;
- and
- directly measuring a relative shift between interference patterns caused by said first pair of slits and said second pair of slits.
A method of measuring the phase shift between two regions of a phase shift mask, said method comprising the steps of:
- providing a workpiece including a first transparent region and a second transparent region having a different phase shift characteristic than said first transparent region;
- providing a first aperture including a pair of slits having substantially similar phase shift characteristics;
- directing electromagnetic radiation through said slits in said aperture and then through said workpiece, such that electromagnetic radiation passing through one of said slits passes through said first transparent region and electromagnetic radiation passing through the other of said slits passes through said second transparent region;
- and
- directly measuring a relative shift between interference patterns caused by electromagnetic radiation passing through said pair of slits and said workpiece.
An apparatus for measuring the phase shift between two regions of a phase shift mask, comprising:
- a workpiece including a first pair of slits each having a substantially similar phase shift characteristic and a second pair of slits each of said second pair of slits having a different phase shift characteristic;
- a source of electromagnetic radiation that may be directed through said first pair of slits and said second pair of slits on said workpiece;
- and
- means for directly measuring a relative shift between interference patterns caused by said first pair of slits and said second pair of slits.
An apparatus for measuring the phase shift between two regions of a phase shift mask, comprising:
- a workpiece including a first transparent region and a second transparent region having a different phase shift characteristic than said first transparent region;
- a first aperture including a pair of slits having substantially similar phase shift characteristics;
- a source of electromagnetic radiation that may be directed through said slits in said aperture and then through said workpiece, such that electromagnetic radiation passing through one of said slits passes through said first transparent region and electromagnetic radiation passing through the other of said slits passes through said second transparent region;
- and
- means for directly measuring a relative shift between interference patterns caused by electromagnetic radiation passing through said pair of slits and said workpiece.
Dependencies are inferred from the claim text.