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US 9,040,910 B2Granted
Multi-column electron beam inspection that uses custom printing methods
AssigneeTao Luo
InventorTao Luo
Life of this patent
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Abstract
A method of testing for photomask print errors includes dividing a photomask print into sub-regions and inspecting each sub-region with a different (e.g., electron) beam column, each sub-region aligned with a beam column axis during a calibration process. The different sub-regions may be inspected on different photomask prints on a wafer plane.
Claims13
A semiconductor wafer inspection process, comprising:
- creating an inspection test wafer from a custom arrangement of photomask exposure layout different from a production print layout of a production wafer;
- inspecting the inspection test wafer for defects using a multi-column electron beam system;
- processing the inspection test wafer under the same conditions as the production wafer, except that the photolithography exposure step is modified to create an arrangement of photomask prints on the inspection test wafer plane to allocate and align sub-regions of each photomask print to a different beam column;
- and
- inspecting each one of the sub-regions in the repeated photomask prints on the wafer plane using a different column of the multi-column electron beam system.
2 more elements
Dependencies are inferred from the claim text.