Ceramics and glasses · Future bench (deployed)

YF3 and YOF coatings

YOFvalues describe: aerosol-deposited YOF

What it enables

Start fluorinated, so fluorine plasmas cannot convert them: less erosion, fewer particles, less process drift than sprayed yttria.

Status and pusher

In mass-production evaluation and deployment; aerosol-deposited YOF matches yttria erosion with zero porosity. Pushed by Korean and Japanese coating houses and tool OEMs.

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; aerosol-deposited films are dense enough to tolerate it, sprayed ones less so
Forbidden	aggressive chemistry on porous sprayed grades
Limit	coating density, which is the whole difference from Y₂O₃

Vacuum and outgassing

Outgassing, unbaked (10 h)	1e-9 mbar·L/s/cm²
Outgassing, baked	1e-12 mbar·L/s/cm²
Vapour pressure	none

Temperature

Bake, assembled	450 °C
Vacuum degas	600 °C
Metallurgical limit	stable to 1200 °C

Thermal

CTE	8 ppm/K
Thermal conductivity	13 W/m·K
Specific heat	450 J/kg·K
Emissivity	0.8
Melting / softening	2410 °C

Mechanical

Strength	coating
Elongation	nil
Young's modulus	150 GPa
Hardness	500–700 HV
Density	5.01 g/cm3

Electrical and magnetic

Relative permeability	1.0
Resistivity	>1e12 Ω·cm

Engineering

Corrosion	the point of the material: fluorine and chlorine plasma resistance
Joining	aerosol or plasma deposited
Process notes	far less particulation than Y₂O₃ alone
Availability and cost	specialist coaters in the semiconductor supply chain

Sources · 2

1. Y2O3 vs YF3 in production chambers
2. Aerosol-deposited YOF, plasma resistance

Used by

Essays

• The Floor Under the Fab

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