Fused Quartz
Quartz Focus Ring & Etch Ring
Precision-machined fused quartz focus rings, etch rings, and edge rings for plasma etching and CVD chambers — ±0.01 mm tolerance, Ra 0.1 μm surface finish.
Custom dimensions and specifications available upon request.
Technical Specifications
| Parameter | Value |
|---|---|
| Material | Fused quartz Grade 1 or Synthetic fused silica Grade 2 |
| OD Tolerance | ±0.02 mm |
| ID Tolerance | ±0.02 mm |
| Flatness (Top Surface) | < 0.02 mm |
| Parallelism | < 0.02 mm |
| Surface Roughness | Ra 0.1–0.4 μm |
Quartz Focus Rings & Etch Rings
Focus rings (also called edge rings or etch rings) are precision annular quartz components that surround the wafer in plasma etch and deposition chambers. They serve multiple functions:
- Electrical focusing — shape the plasma sheath uniformity at the wafer edge
- Thermal uniformity — conduct or redistribute heat at the wafer perimeter
- Edge protection — consume plasma species at the wafer edge, protecting the chuck
- Alignment reference — locate the wafer centrally on the electrostatic chuck (ESC)
Standard Geometries
Flat Focus Ring
The simplest geometry — a flat annular disc with tight flatness and parallelism specifications.
| Wafer Size | ID (Nominal) | OD (Nominal) | Thickness | Key Tolerance |
|---|---|---|---|---|
| 6” (150 mm) | 152 mm | 220–280 mm | 3–8 mm | OD/ID ±0.02 mm |
| 8” (200 mm) | 202 mm | 280–360 mm | 3–10 mm | OD/ID ±0.02 mm |
| 12” (300 mm) | 302 mm | 380–460 mm | 4–12 mm | OD/ID ±0.02 mm |
Stepped / Profile Ring
Complex cross-section with OEM-specified step geometry for conformal fit to chamber hardware.
All stepped and profiled rings are produced from 2D drawings. Common profile features:
- Chamfered inner edge (contact with wafer edge)
- Upper step for alignment tab or locating pin
- Counterbore for mounting screw clearance
- Undercut for gas flow passage
Plasma Erosion Considerations
Quartz focus rings erode under plasma exposure. Life span depends on plasma chemistry, power, and bias:
| Process | Approximate Ring Life |
|---|---|
| Si-based etch (SF₆/C₄F₈) | 200–400 RF hours |
| Metal etch (Cl₂/BCl₃) | 100–200 RF hours |
| Oxide etch (CHF₃/CF₄) | 300–600 RF hours |
| CVD (SiH₄/TEOS) | 500–1000 hours |
Tuguan Semiconductor supplies compatible replacement rings to OEM geometry specifications. Provide the OEM part number or drawing — we will reverse-measure and reproduce to ±0.02 mm.
Quality & Cleanliness
All focus rings are:
- Machined in dedicated quartz-only cells (no cross-contamination from metals)
- Ultrasonically cleaned in DI water + megasonic rinse
- Dried and inspected in ISO Class 7 cleanroom
- Double-bagged in ESD-safe packaging for shipment
Related Products
Quartz Baffle & Insert
Custom-machined fused quartz baffles, liners, and thermal shields for semiconductor furnace tubes, diffusion systems, and CVD reactors.
Quartz Viewport Window
Optically polished fused quartz and sapphire viewport windows for semiconductor process chamber monitoring — UV to mid-IR transmission, hermetic metal or CF flanges.
Quartz Diffusion Tube
High-purity fused quartz diffusion and oxidation tubes for semiconductor furnaces — straight bore, flanged, and bell-end configurations for 4" to 12" wafer processes.
Ready to order or need a custom size?
Submit your drawing or specifications — we respond within 24 hours.