Properties                     Target                            Tolerance

Material                      High-purity and monocrystallineAl₂O₃     ﹥99.995%

Diameter                     50.8 mm (2inch)                     ±0.1mm

Thickness                     430 μm                          ±25mm

Surface orientation of a-plane      0°                              ±0.1°

Surface orientation of m-plane     0.2°                            ±0.1°

Primary flat length               16mm                            ±1mm

Primary flat orientation           a-plane                            ±1.5°

Back side roughness              0.8μm                           ±0.3μm

Front side roughness              ≦0.2nm 

Chamfering shape               Rounded

Total Thick Variation, TTV          ≦10μm

SORI                           ≦10μm

Bow                           ±10μm