High-Purity Alumina Ceramic Ring for CVD / PVD Process Chambers
St.Cera‘s ceramic ring is specifically designed for use in CVD (Chemical Vapor Deposition) and PVD (Physical Vapor Deposition) process chambers. Manufactured from 99.8% high-purity alumina (Al₂O₃), this ring serves as a chamber liner, focus ring, or process kit component to confine plasma and protect chamber walls from erosion. The material offers excellent plasma resistance, high dielectric strength (15×10⁶ V/m), and thermal stability up to 1600°C, ensuring long service life in aggressive fluorine-based plasma environments. Precise dimensional tolerances (±0.05 mm on ID/OD) and flatness (≤10 μm) enable consistent wafer edge positioning, improving deposition uniformity and reducing particle generation.
Specifications (based on 99.8% Al₂O₃):
| Property | Value |
| Material | 99.8% Alumina (Ivory) |
| Density | 3.93 g/cm³ |
| Water Absorption | 0% |
| Flexural Strength | 361 MPa |
| Fracture Toughness | 3–4 MPa·m¹/² |
| Vickers Hardness | 16 GPa |
| Young’s Modulus | 380 GPa |
| Thermal Conductivity | 32 W/m·k |
| Thermal Expansion (25–1000°C) | 7.2×10⁻⁶/℃ |
| Dielectric Strength | 15×10⁶ V/m |
| Specific Resistance | >10¹⁴ Ω·cm |
| Max Operating Temperature | 1600°C |
Applications:
- · CVD chamber focus rings and edge rings
- · PVD chamber shield rings and clamp rings
- · Etch chamber liners and cover rings
- · Plasma confinement rings in dielectric etch systems
Manufacturing Process:
Isostatic pressing → green machining → sintering at 1600°C → CNC ID/OD grinding → surface lapping → ultrasonic cleaning → 100% CMM inspection. Ultra-smooth surface finish (Ra ≤0.4 μm) minimizes particle adhesion.
Quality Control:
- · 100% dimensional check (ID, OD, thickness, flatness)
- · Dye penetrant inspection for surface micro-cracks
- · Dielectric strength test per ASTM D149
- · No visible discoloration or porosity under 20× microscope
Advantages over Metal or Quartz Rings:
- · 5–10× longer lifetime than aluminum rings in fluorine plasma
- · No metal contamination in thin films
- · Higher plasma resistance than quartz (no erosion pits)
- · Maintains electrical insulation >10¹⁴ Ω·cm even after long-term use
Alternative Material — Silicon Nitride (Si₃N₄):
For applications requiring even higher fracture toughness (6.2 MPa·m¹/²) and better thermal shock resistance (expansion coefficient 3.2×10⁻⁶/℃), Si₃N₄ rings are available. However, alumina is more cost-effective for most CVD/PVD applications. Please specify material preference when ordering.
Customization:
- · Through-holes, stepped profiles, or counterbores for mounting
- · Y₂O₃-coated surface for enhanced plasma resistance (optional)
- · Laser engraving of part number / lot code
Note: The above data strictly follows the supplied Al₂O₃ property table. For Si₃N₄ rings, refer to the separate Si₃N₄ datasheet provided.
