Thermal Spray Technology Blog
Suspension Plasma Spray for dense Y2O3 (yttria) coatings
- Details
- Published Date
Properties
Suspension plasma spray delivers fine submicron particles to the Axial III high energy plasma torch to produce unique, dense coatings that are especially useful in erosion and corrosion resistant applications.
Application
High purity materials of sintered, bulk Y2O3 or anodized aluminum are being used as erosion resistant and high electric strength liners for plasma etching chambers in the semiconductor industry. Maintenance cycles require replacement when the liners are substantially worn and vary with liner composition. Yttria is the preferred liner material due to its superior anti-erosion properties and lower maintenance frequencies.
Problem
The high cost and brittleness of sintered, bulk Y2O3 are prohibitive to most industrial applications.
Mettech Solution
Mettech has developed a suspension plasma spray coating using its proprietary NanoFeed delivery system that provides superior erosion, hardness and porosity properties as compared to APS Y2O3 coatings.
| Coatings | Porosity (%) | Hardness Hv0.2 | Ratio of Ra of erode area | Erosion rate, nm/min |
| Y2O3 bulk (sintered) | ~0 | 710 | 1 | 45 |
| Commercial Y2O3 coatings (SG-100 torch with agglomerated powder) | 4.2 | 400 | 2.3 | 85 |
| Axial III with agglomerated powder | 4.5 | 590 | 2.2 | 74 |
| Axial III Suspension Plasma Spray | 0.3 | 620 | 0.6 | 65 |
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| Photomicrograph of the microstructure of a dense, suspension plasma spray Y2O3 coated substrate as received. | Photomicrograph of SEM image of suspension plasma spray coating as received | Photomicrograph of SEM Image of suspension plasma spray coating after erosion tests |
Reference: “Structural, Mechanical and Erosion Properties of Plasma Spray Yttrium Oxide Coatings by Axial Injection of Fine Powder Slurries for Semiconductor and Flat-Panel-Display Applications”, J. Kitamura, H. Ibe, F. Yuasa (Fujimi Inc.), Z. Tang, A. Burgess, (Northwest Mettech Corp.)