Wafer handling ceramic parts lift, hold and transfer silicon wafers inside process tools. They work in vacuum or controlled atmosphere, at temperature, and in contact with a surface that cannot tolerate contamination.
Fingers are the elements that touch the wafer edge or underside. Every contact face is polished and every edge radiused, because a chipped or rough finger generates the particles that a cleanroom cannot tolerate and marks the wafer it holds.
Alumina is the default engineering ceramic. It combines high hardness (1500-1700 HV) with good electrical insulation and chemical inertness at a lower cost than most technical ceramics, and in 99.8% purity it holds strength to 1700°C while resisting most acids, alkalis and solvents.
It is not the toughest option. At 3-4 MPa·m½ fracture toughness, sharp impact or point loading will chip an edge, so chamfers and radii belong in the drawing from the start.
Specifications
| Types | end effectors, arms, forks, fingers, boats |
| Wafer sizes | 100, 150, 200 and 300 mm |
| Flatness | to 0.01 mm |
| Contact surfaces | polished, Ra 0.2 µm or better |
| Edge condition | radiused, free of chipping |
| Cleanliness | cleaned and packed for cleanroom entry |
| Atmosphere | vacuum, inert or high-temperature oxidising |
Alumina Properties
| Composition | Aluminium oxide, 96% / 99.5% / 99.8% |
| Density | 3.70-3.95 g/cm³ |
| Vickers hardness | 1500-1700 HV |
| Flexural strength | 300-400 MPa |
| Fracture toughness | 3-4 MPa·m½ |
| Max. service temperature | 1500°C (99.8%: 1700°C) |
| Thermal conductivity | 25-35 W/m·K |
| Thermal expansion (20-1000°C) | 8.0 ×10⁻⁶/K |
Machining and Tolerances
Handling parts are ground from fine-grained stock and finished to a controlled surface, with edges radiused and all faces cleaned for vacuum service. We pay particular attention to the contact surfaces, since a rough contact face is both a particle source and a wear site on the wafer itself.
Where It Is Used
- End effectors and forks for wafer transfer robots
- Handling arms and lift pins in CVD, PVD and diffusion tools
- Boats and carriers for furnace processing
- Chuck and electrostatic chuck blanks
- Insulating mounts and shields inside process chambers
Frequently Asked Questions
Which material should I choose for a wafer handling part?
Alumina for general handling and electrical isolation, silicon carbide where stiffness and thermal conductivity matter, and silicon nitride where the part sees thermal cycling or contact stress. The choice depends on the tool atmosphere and temperature.
Can you supply parts cleaned for cleanroom use?
Yes. Parts are cleaned, inspected for edge chipping and packed for cleanroom entry, and we can supply material certification on request.