FFKMvalues describe: Kalrez semiconductor grade
Semiconductor equipment & lithographyChipmakers (foundries & IDMs)
Why it wins
The seal that survives the plasma: fully fluorinated backbones shrug off O2 and fluorine radicals to 300 C plus, where FKM chars and sheds particles into the chamber.
Why not the alternative
Viton in a plasma tool becomes a particle source and an etch casualty; metal seals cannot do slit valves and doors.
Watch out
Price per O-ring is 10 to 100x FKM: specify by position, not by habit.
Properties
The values below are candidate: compiled from the sources named, not yet individually validated.
Provisional provenance: Elastomer supplier data and vacuum seal practice; Semiconductor chamber materials and plasma-resistant coating literature.
Wet cleaning
| Recipe | IPA wipe, air dry, vacuum bake 200 °C before service |
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| Forbidden | as FKM: ketones, and any lubricant on the seal face |
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| Limit | compound-specific: semiconductor grades are qualified as cleaned, so do not improvise |
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Vacuum and outgassing
| Outgassing, unbaked (10 h) | 1e-7 mbar·L/s/cm² |
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| Outgassing, baked | 1e-9 mbar·L/s/cm² |
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| Vapour pressure | low |
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Temperature
| Bake, assembled | 300 °C |
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| Vacuum degas | 300 °C |
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| Metallurgical limit | 250–325 °C by compound |
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Thermal
| CTE | 200 ppm/K |
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| Thermal conductivity | 0.2 W/m·K |
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| Specific heat | 1100 J/kg·K |
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| Emissivity | 0.9 |
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Mechanical
| Strength | 12–17 tens MPa |
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| Tensile | 12–17 MPa |
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| Elongation | 150–250 % |
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| Young's modulus | 0.01 GPa |
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| Hardness | 70–90 Shore A |
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| Density | 2 g/cm3 |
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Electrical and magnetic
| Relative permeability | 1.0 |
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| Resistivity | >1e13 Ω·cm |
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Engineering
| Corrosion | essentially universal |
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| Joining | compressed in a groove |
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| Process notes | check the compound, not the brand |
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| Availability and cost | roughly ten times the price of FKM |
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Grades
| Kalrez 8085 | plasma and particle-critical positions |
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| Kalrez 9100 | high temperature plasma duty, about 325 C |
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| Chemraz 615 class | broad chemical service alternative |
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Sources · 1
- DuPont Kalrez semiconductor grade data
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