Print quality test structure for lithographic device manufacturing
AssigneeBookham Technology PLC
InventorsDavid Seniuk, Marcel Boudreau, Maxime Poirier
Life of this patent
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Abstract
Disclosed is a print quality test structure for devices manufactured by lithography. The test structure allows for visual inspection of the print quality of the device. The test structure decouples the effects of overexposure, underexposure and focus so that corrections can be made for future device manufacturing. By visually inspecting each device during lithography, devices of poor quality can be reworked, and costly testing on all devices can be avoided through device screening.
Claims15
A method of forming a lithographic device by a lithographic process involving the projection and focusing of radiant energy passing through a reticle having a selected pattern, thereon such as to expose a photoresist material on a wafer surface to the selected pattern, wherein the reticle has a print quality configuration thereon capable of producing a test structure on the wafer surface in close proximity to the selected pattern or a selected portion thereof, the test structure being capable of being visually inspected to indicate the quality of the selected pattern which is formed on the wafer surface, the print quality configuration comprising a series of characters incrementing in size according to a binary pattern to a resolution exceeding the resolution capabilities of the lithographic process.
Dependencies are inferred from the claim text.