Properties                     Target                            Tolerance

Material                      High-purity and monocrystallineAl₂O₃     ﹥99.995%

Diameter                     100 mm (4inch)                     ±0.1mm

Thickness                     650 μm                          ±25mm

Surface orientation of a-plane      0°                              ±0.1°

Surface orientation of m-plane     0.35°                            ±0.1°

Primary flat length               31mm                            ±1mm

Primary flat orientation           a-plane                            ±1.5°

Chamfering shape               double side 45°                   ±5°

Chamfering width                150μm                          ±50μm

Back side roughness              0.8μm                           ±0.3μm

Front side roughness              ≦0.2nm 

Total Thick Variation, TTV          ≦20μm

SORI                           ≦25μm

Bow                           ±15μm