Wafer products

Controlled expansion alloy wafers up to 12” diameter supplied as lapped, polished or polished and metallized wafers, expansion matched to compound semiconductor materials.

Our alloy wafers are used for:

  • Medium and high brightness LED
  • Photovoltaic cells

Alloys chosen are typically CE6F and CE7F, and these are used to replace sapphire – GaAs.

Advantages of CE6F controlled expansion alloy

  • CTE matching of compound semiconductor materials
  • Superior thermal and electrical properties
  • Enhanced reliability
  • Low cost
Typical specification for 100 mm wafer
Material CE6F
Diameter 100 mm +/-0.05 mm
Flat 32 mm +/-0.02 mm
Chamfer 220 μ +/-50 μ
Thickness 750 μ +/- 20 μ
TTV <5 μ
Surface Polished both sides Ra < 20 nm
Bow weight < 20 μ
Comparative property data for low expansion substrates
PropertyGeSiGaAsSapphireCE6
CTE 25–300ºC 5.8 3 6.8 5.8 6.2
Density g/cc 5.32 2.3 5.3 4.0 2.45
Young's Modulus, GPa 130 112 85 350 130
Thermal conductivity, W/mK 64 150 40 35 110
Electrical resistivity, μΩ.cm 50 105 107 1014 115
Plateability Good Poor Poor Poor Good
Machinability (CNC/EDM) Poor Poor Poor Poor Good