Multilayer attenuating phase-shift masks
AssigneeE.I. du Pont de Nemours and Company
InventorPeter Francis Carcia
Life of this patent
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Abstract
Disclosed are attenuating embedded phase shift masks capable of producing a phase shift of 180° with an optical transitivity of at least 0.001 at a selected lithographic wavelength less than 200 nm. The masks are comprised of distinct contiguous alternating contiguous layers of an optically transparent material consisting essentially of an oxide selected from the group consisting of oxides of Al and Si and layers. of an optically absorbing material consisting essentially of a nitride selected from the group consisting of nitrides of Al and Si. Such masks are commonly known in the art as attenuating (embedded) phase shift masks or half-tone phase shift masks.
Claims3
An attenuating embedded phase shift mask, capable of producing a phase shift of 180° with an optical transmissivity of at least 0.001 at a selected lithographic wavelength <200 nm, said mask comprising:
- distinct alternating contiguous layers of an optically transparent material consisting essentially of an oxide selected from the group consisting of oxides of Al and Si and layers of an optically absorbing material consisting essentially of a nitride selected from the group consisting of nitrides of Al and Si.
Dependencies are inferred from the claim text.