Y2O3values describe: APS Y₂O₃
Semiconductor equipment & lithographyChipmakers (foundries & IDMs)
Why it wins
Resists fluorine plasmas better than alumina or quartz: the standard sprayed liner of etch and deposition chambers.
Why not the alternative
Fluorine plasmas convert the surface to YOxFy, which drifts the process and sheds particles: YF3 and YOF are taking the position (see future bench).
Watch out
APS pores and unmelted grains are tomorrows wafer defects.
Properties
The values below are candidate: compiled from the sources named, not yet individually validated.
Provisional provenance: Semiconductor chamber materials and plasma-resistant coating literature.
Wet cleaning
| Recipe | DI rinse and dry only, after grit-blast preparation of the substrate before spraying |
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| Forbidden | aggressive chemistry: the as-sprayed coating is porous and holds it |
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| Limit | coating porosity, which is also why it particulates |
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Vacuum and outgassing
| Outgassing, unbaked (10 h) | 1e-9 mbar·L/s/cm² |
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| Outgassing, baked | 1e-12 mbar·L/s/cm² |
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| Vapour pressure | none |
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Temperature
| Bake, assembled | 450 °C |
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| Vacuum degas | 600 °C |
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| Metallurgical limit | stable to 1500 °C |
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Thermal
| CTE | 8 ppm/K |
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| Thermal conductivity | 13 W/m·K |
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| Specific heat | 450 J/kg·K |
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| Emissivity | 0.8 |
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| Melting / softening | 2410 °C |
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Mechanical
| Strength | coating |
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| Elongation | nil |
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| Young's modulus | 150 GPa |
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| Hardness | 500–700 HV |
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| Density | 5.01 g/cm3 |
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Electrical and magnetic
| Relative permeability | 1.0 |
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| Resistivity | >1e12 Ω·cm |
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Engineering
| Corrosion | the point of the material: halogen plasma resistance |
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| Joining | air plasma sprayed onto the finished part |
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| Process notes | porosity drives particle generation, which is why YOF displaced it |
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| Availability and cost | specialist coaters |
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Grades
| 99.9 percent APS powder | standard sprayed liner |
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| 99.99 percent, fine cut | particle-critical positions, tighter defect specs |
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| Suspension plasma spray | denser, smoother than dry APS where budget allows |
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Sources · 2
- Y2O3 vs YF3 erosion and particles, mass-production chambers
- APS Y2O3 and YF3 under NF3 plasma
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