Sapphire substrates and methods of making same
AssigneeSaint-Gobain Ceramics & Plastics, Inc.
InventorsBrahmanandam V. Tanikella, Matthew A. Simpson, Palaniappan Chinnakaruppan, Robert A. Rizzuto, Ramanujam Vedantham
Life of this patent
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Abstract
A sapphire substrate includes a generally planar surface having a crystallographic orientation selected from the group consisting of a-plane, r-plane, m-plane, and c-plane orientations, and having a nTTV of not greater than about 0.037 μm/cm2, wherein nTTV is total thickness variation normalized for surface area of the generally planar surface, the substrate having a diameter not less than about 9.0 cm.
Claims17
A method of providing a sapphire substrate lot containing sapphire substrates, comprising:
- grinding a surface of each sapphire substrate using an abrasive such that the first surface has a c-plane orientation, wherein the sapphire substrate lot contains at least 20 sapphire substrates, each sapphire substrate having a first surface that has (i) a c-plane orientation, (ii) a crystallographic m-plane misorientation angle (θm), and (iii) a crystallographic a-plane misorientation angle (θa), wherein at least one of (a) a standard deviation am of misorientation angle θm is not greater than about 0.0130 degrees and (b) a standard deviation σa of misorientation angle θa is not greater than about 0.0325 degrees.
A sapphire substrate lot, comprising at least 20 sapphire substrates, each sapphire substrate having a first surface that has (i) a c-plane orientation, (ii) a crystallographic m-plane misorientation angle (θm), and (iii) a crystallographic a-plane misorientation angle (θa), wherein at least one of (a) a standard deviation am of misorientation angle θm is not greater than about 0.0130 degrees and (b) a standard deviation σa of misorientation angle θa is not greater than about 0.0325 degrees.
Dependencies are inferred from the claim text.