Wafers
Controlled expansion (CE) 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 Osprey® CE6F and CE7F, and these are used to replace sapphire – GaAs. Some of the advantages of using Osprey® CE6F include:
- CTE matching of compound semiconductor materials
- Superior thermal and electrical properties
- Enhanced reliability
- Low cost
| Material | Osprey 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 |
| Property | Ge | Si | GaAs | Sapphire | Osprey® CE6 |
|---|---|---|---|---|---|
| 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 |