Patent ID: 11906699
Assignee: CORNING INCORPORATED
Field: Materials, metallurgy (Chemistry)
Classification: CPC C  G | IPC B  C  G

Claim 15:
16. An article comprising:
an inorganic oxide substrate comprising opposing major surfaces; and
an optical film structure disposed on a first major surface of the inorganic oxide substrate, the optical film structure comprising a physical thickness from about 50 nm to less than 500 nm, a plurality of alternating high index and low index layers with a first low index layer in direct contact with the first major surface, and a capping low index layer,
wherein each low index layer comprises a silicon-containing oxide and each high index layer comprises silicon nitride or silicon oxynitride,
wherein the article exhibits a hardness of 8 GPa or greater measured at an indentation depth of about 100 nm or a maximum hardness of 9 GPa or greater measured over an indentation depth range from about 100 nm to about 300 nm, the hardness and the maximum hardness measured by a Berkovich Indenter Hardness Test, and
further wherein one of the high refractive index layers in the optical film structure is the thickest layer in the layers of the optical film structure below the capping index layer.