• Sapphire (single crystal of Al₂O₃ ) is being used extensively as a substrate for III-V nitrides and for many other epitaxial films 
• Orientation: C-axis[0001]( +/-0.3 Deg) with Standard Flat
• Diameter: 2" +/- 0.3mm
• Thickness: 500um +/- 25 um
• Major Flat: A-axis[11-20]+/-0.2^o
• Surface Finish: Front sides: Epi- polished Ra<0.5nm (by AFM)
• Back side: Epi- polished , <0.5nm(by AFM)
• TTV: < 10um
• Polished surface: Two side epi polished by special CMP technology
• Package: Each wafer is packed in 1000 class clean room  

Typical Properties:

• Crystal Structure: Hexagonal. a=4.758 Angstroms c=12.99 Angstroms
• Melting Point: 2040 degree C
• Density: 3.97 gram/cm² 
• Growth Technique: CZ
• Crystal Purity:  >99.99%
• Hardness: 9 ( mohs)
• Thermal Expansion: 7.5x10^{-6 (}/ ^oC)
• Thermal Conductivity: 46.06 @ 0 ^oC, 25.12 @ 100 ^oC, 12.56 @ 400 ^oC ( W/(m.K) ) 
• Dielectric Constant: ~ 9.4 @300K  at A axis ~ 11.58@ 300K at C axis
• Loss Tangent at 10 GHz: < 2x10^-5  at A axis,  <5 x10^-5  at C axis