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AssigneeThe Regents of the Unviersity of California
InventorsPaul B. Mirkarimi, Claude Montcalm
Estimating the term…
A buffer-layer located between a substrate and a multilayer for counteracting stress in the multilayer. Depositing a buffer-layer having a stress of sufficient magnitude and opposite in sign reduces or cancels out deformation in the substrate due to the stress in the multilayer. By providing a buffer-layer between the substrate and the multilayer, a tunable, near-zero net stress results, and hence results in little or no deformation of the substrate, such as an optic for an extreme ultraviolet (EUV) lithography tool. Buffer-layers have been deposited, for example, between Mo/Si and Mo/Be multilayer films and their associated substrate reducing significantly the stress, wherein the magnitude of the stress is less than 100 MPa and respectively near-normal incidence (5.degree.) reflectance of over 60% is obtained at 13.4 nm and 11.4 nm. The present invention is applicable to crystalline and non-crystalline materials, and can be used at ambient temperatures.
In a device including a multilayer of high reflectance material and a substrate, the improvement comprising:
A method for reducing or negating multilayer film stress induced deformation of optics, comprising:
In an optic adapted for use in an extreme ultraviolet lithography tool and having a high reflectance multilayer, the improvement comprising:
A method for adjusting stress in a molybdenum containing multilayer of high reflectance material deposited on a substrate, including:
Dependencies are inferred from the claim text.