•      •  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]  off  M-plane(1-100) 0.2^o+/-0.1^o
  
•      •  Diameter: 50.8mm +/- 0.1mm
•      •  Thickness: 500um +/- 15 um
•      •  Major Flat: A-axis[11-20]+/-0.2^o
•      •  Major Flat Length: 16mm +/- 1.0mm
•      •  Surface Finish: Front side: Epi- polished , Ra< 0.3 nm(by AFM); Back side: Fine ground, Ra= 0.8-1.2 um
  
•      •  TTV: <= 5um
•      •  Bow:<= -6-0 um
•      •  WARP<= 10um
•      •  LTV<=1.5um(5x5mm^2)
•      •  TIR<= 10um
•      •  Polished surface: One 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

 Please click here for detail data