Sapphire substrates and methods of making same
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/cm 2 , 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.
1. A sapphire substrate, comprising:
a generally planar surface having a crystallographic orientation selected from the group consisting of a-plane, r-plane, m-plane, and c-plane orientation, and having a nTTV of not greater than about 0.032 μm/cm 2 , 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.
2. The sapphire substrate of claim 1 , wherein the generally planar surface has a roughness Ra not greater than about 10.0 Å.
3. The sapphire substrate of claim 1 , wherein the substrate has a nFlatness of not greater than 0.100 μm/cm 2 , wherein nFlatness is flatness of the generally planar surface normalized for surface area of the generally planar surface.
4. The sapphire substrate of claim 1 , wherein the substrate has a nBow of not greater than 0.100 μm/cm 2 , wherein nBow is bow of the substrate normalized for surface area of the generally planar surface.
5. The sapphire substrate of claim 1 , wherein the substrate has a nWarp of not greater than 0.190 μm/cm 2 , wherein nWarp is warp of the substrate normalized for surface area of the generally planar surface.
6. The sapphire substrate of claim 1 , wherein the crystallographic orientation is selected from the group consisting of c- and r-plane orientations.
7. The sapphire substrate of claim 6 , wherein the crystallographic orientation is the c-plane orientation.
8. The sapphire substrate of claim 7 , wherein the generally planar surface of the sapphire substrate is tilted away from the c-plane at a tilt angle of not greater than about 2.0°.
9. The sapphire substrate of claim 1 , wherein the generally planar surface of the sapphire substrate has a dislocation density of not greater than 1E8/cm 2 .
10. The sapphire substrate of claim 1 , wherein the generally planar surface has a surface area of not less than about 70 cm 2 .
11. The sapphire substrate of claim 1 , wherein the substrate has a diameter of not less than about 10.0 cm.
12. A sapphire substrate, comprising:
a generally planar surface having a crystallographic orientation selected from the group consisting of a-plane, r-plane, m-plane, and c-plane orientation, and having a nFlatness of not greater than 0.100 μm/cm 2 , wherein nFlatness is flatness of the generally planar surface normalized for surface area of the generally planar surface, and the substrate has a diameter not less than about 6.5 cm and a thickness not greater than about 525 μm.
13. The sapphire substrate of claim 12 , wherein the TTV is not greater than about 2.85 μm.
14. The sapphire substrate of claim 12 , wherein the thickness is not greater than about 500 μm.
15. The sapphire substrate of claim 12 , wherein the generally planar surface has a roughness Ra not greater than about 5.0 Å.
16. The sapphire substrate of claim 12 , wherein the substrate has a nBow of not greater than 0.100 μm/cm 2 , wherein nBow is bow of the substrate normalized for surface area of the generally planar surface.
17. The sapphire substrate of claim 12 , wherein the substrate has a nWarp of not greater than 0.190 μm/cm 2 , wherein nWarp is warp of the substrate normalized for surface area of the generally planar surface.
18. The sapphire substrate of claim 12 , wherein the crystallographic orientation is selected from the group consisting of c- and r-plane orientations.
19. The sapphire substrate of claim 18 , wherein the crystallographic orientation is the c-plane orientation and the generally planar surface of the sapphire substrate is tilted away from the c-plane at a tilt angle of not greater than about 2.0°.
20. The sapphire substrate of claim 12 , wherein the generally planar surface of the sapphire substrate has a dislocation density of not greater than 1E8/cm 2 as measured by x-ray topography.
21. The sapphire substrate of claim 12 , wherein the generally planar surface has a surface area of not less than about 40 cm 2 .
22. The sapphire substrate of claim 12 , wherein the substrate has a diameter of not less than about 7.5 cm.
23. A sapphire substrate, comprising:
a generally planar surface having a crystallographic orientation selected from the group consisting of a-plane, r-plane, m-plane, and c-plane, and having a nTTV of not greater than about 0.025 μm/cm 2 , wherein nTTV is total thickness variation normalized for surface area of the generally planar surface.
24. The sapphire substrate of claim 23 , wherein the nTTV is not greater than about 0.020.
25. The sapphire substrate of claim 23 , wherein the nTTV is not greater than about 0.018.
26. The sapphire substrate of claim 23 , wherein substrate has a diameter not less than about 9.0 cm.