High Purity Alumina Ceramic Dome Cover for Plasma Etch Chambers

Application Scenarios — High Purity Alumina Ceramic Dome Cover

• Industrial Plasma Etch Equipment

  ✅Key Advantages

  1. Stable RF coupling and plasma footprint – In inductively coupled etch reactors that wrap the coil around a sintered alumina dome, tuned dome thickness and curvature help keep plasma density and etch rate uniform across the wafer in repeated runs.

  2. Mechanical margin under coil load and thermal cycling – Using high purity ~99.7% alumina for the dome window provides bending strength around 350 MPa and fracture toughness near 4.5 MPa·m½, roughly 2.5–3.7 times higher than typical yttria windows, giving an extra safety margin against cracking in high-power etch tools.

  3. Controlled surface evolution and particle behaviour – Alumina dome materials with optimized microstructure and initial roughness show more predictable roughness growth under CF₄ plasma, which helps keep the inner dome surface from turning into a strong particle source during long etch campaigns.

  ✅ Problem Solved

  A metal etch line originally used mixed dome materials and cleaned chambers every 90–100 plasma hours to stay inside defect limits. After switching to a High Purity Alumina Ceramic Dome Cover with controlled thickness and roughness, the clean point moved to about 130–140 hours with the same recipe and wafer mix. Over a quarter, dome-related maintenance stops dropped, and the line recovered several production days that would previously have been lost to teardown and requalification.

• PVD and CVD Coating Systems

  ✅Key Advantages

  1. More stable thickness uniformity window – When used as the chamber dome in magnetron sputtering tools, a High Purity Alumina Ceramic Dome Cover helps keep coating thickness non-uniformity within typical ±3–5% over full substrate areas by holding the dome geometry and target–substrate spacing stable under heat and deposition load.

  2. Reduced dome change frequency under metal vapour load – In TiN/TiAlN hard coating and similar metal film PVD processes, alumina domes in suitable chemistries can stay in service for several hundred coating hours per campaign before changeout, whereas some quartz domes in comparable duty are often scheduled for replacement after roughly 150–200 hours because of erosion and stress cracking.

  3. Predictable thermal behaviour for process recipes – With controlled wall thickness and thermal conductivity of high purity alumina on the order of 20–30 W·m⁻¹·K⁻¹ in the relevant temperature range, the High Purity Alumina Ceramic Dome Cover provides a stable, repeatable thermal boundary condition so that PVD/CVD recipes tuned once can be re-used across campaigns with fewer temperature re-qualification steps.

  ✅ Problem Solved

  A cutting-tool PVD plant used quartz domes above rotating substrates and replaced them after roughly 180–200 coating hours as the thickness uniformity drifted beyond ±5%. When the positions were converted to High Purity Alumina Ceramic Dome Covers with matched geometry, the service window extended to around 320–360 hours while keeping non-uniformity within about ±4%. The number of dome change events per year decreased, and fewer qualification runs were needed before returning the tools to production.

• R&D and Pilot Vacuum Systems

  ✅Key Advantages

  1. Wide recipe envelope with one dome – A High Purity Alumina Ceramic Dome Cover can support RF powers from tens of watts for process screening up to around 1–2 kW for pilot runs in the same chamber without changing the top hardware.

  2. High cycle count under frequent clean and vent operations – In R&D tools that may be vented and cleaned several times per week, alumina domes qualified for more than 200–300 pump-down/vent cycles keep mechanical integrity through long development programmes.

  3. Repeatable boundary conditions for comparative studies – With stable geometry and thermal behaviour across repeated experiments, the High Purity Alumina Ceramic Dome Cover helps keep run-to-run variation low enough that process changes of only a few percent in etch rate or film thickness can be resolved reliably.

  ✅ Problem Solved

  A university ICP etch tool for shared research was vented and cleaned two to three times per week, and the previous mixed-metal top structure typically needed intervention after 80–100 pump-down/vent cycles. After installation of a High Purity Alumina Ceramic Dome Cover matched to the coil and chamber, the system passed more than 250 documented cycles in one academic year without dome replacement. Etch-rate repeatability improved, so researchers could detect recipe-driven changes of around 3–5% without being masked by hardware drift.

Use Guide — High Purity Alumina Ceramic Dome Cover

• Installation

  1. Inspect the High Purity Alumina Ceramic Dome Cover for visible chips or cracks before installation; do not install damaged domes.
  2. Clean the sealing surfaces of the dome and chamber body with approved wipes and solvents; avoid abrasive tools on polished surfaces.
  3. Use soft lifting tools or dedicated fixtures to handle the dome and avoid point contact on edges.
  4. Align orientation marks and install the dome gradually, ensuring the flange sits flat on the sealing surface without stress.
  5. Tighten bolts in a cross pattern in small steps to distribute load evenly and avoid localized bending of the dome flange.

• Operation

  1. Run the chamber within the recommended power, pressure and temperature range defined for the process and the High Purity Alumina Ceramic Dome Cover material.
  2. Avoid rapid heating or cooling cycles beyond the normal process ramp when possible to limit thermal stress.
  3. Monitor particle counters, plasma stability and arc events; unexpected changes can signal dome surface damage or flaking deposits.

• Storage

  1. Store spare High Purity Alumina Ceramic Dome Covers in clean, dry shelves or crates, in their original cushioning, away from vibration and heavy traffic.
  2. Keep domes away from corrosive liquids or strong temperature swings in the warehouse.
  3. Label each dome with part number, material grade and intended tool model to avoid mis-installation.

• Cleaning and Maintenance

  1. For routine maintenance, remove the High Purity Alumina Ceramic Dome Cover and clean it with approved chamber cleaning agents or non-metallic tools, following your process and safety rules.
  2. Avoid metal scrapers that can leave residue or scratch the alumina surface; use plastic or ceramic tools instead.
  3. After chemical cleaning, rinse thoroughly and dry the dome before reinstalling; avoid leaving liquids trapped in flange or groove areas.

• Typical Misuse Points and How to Handle Them

  1. Over-tightening of flange bolts

  Problem: Uneven over-tightening can cause micro-cracks at the flange.
  Handling: Use torque wrenches with specified torque steps and always follow a cross tightening pattern.

  2. Impact on edges during handling

  Problem: Accidental impact on the edge when moving the High Purity Alumina Ceramic Dome Cover may chip the ceramic.
  Handling: Use padded lifting fixtures and keep a clear path; if chips occur on sealing or critical areas, retire the dome.

  3. Aggressive cleaning with unsuitable tools

  Problem: Hard metal tools or strongly incompatible chemicals can damage the alumina surface and change plasma interaction.
  Handling: Standardize a cleaning procedure with suitable agents and non-metallic tools; train staff and keep records of cleaning cycles per dome.

FAQ — High Purity Alumina Ceramic Dome Cover

1. Q: What is the main function of a High Purity Alumina Ceramic Dome Cover in a plasma etch chamber?
   A: The High Purity Alumina Ceramic Dome Cover forms the upper wall of the plasma zone, defining gas and power distribution while isolating the process from the external environment.
2. Q: Why choose a High Purity Alumina Ceramic Dome Cover instead of a quartz dome?
   A: A high purity alumina dome has higher resistance to plasma erosion and mechanical impact, which can extend maintenance intervals and reduce particles in suitable chemistries.
3. Q: What purity grades are available for the High Purity Alumina Ceramic Dome Cover?
   A: Typical options are 99.5–99.7% alumina, and higher purity ranges can be discussed depending on the dome design and procurement volume.
4. Q: Can the High Purity Alumina Ceramic Dome Cover be produced according to our existing dome drawing?
   A: Yes, ADCERAX normally works from customer drawings or measured samples to produce High Purity Alumina Ceramic Dome Covers with defined tolerances.
5. Q: What is the usual wall thickness of an alumina ceramic dome cover?
   A: Wall thickness is defined by the chamber design and can range from several millimetres upward; the High Purity Alumina Ceramic Dome Cover is machined to match the specified thickness profile.
6. Q: Can we specify a polished inner surface on the High Purity Alumina Ceramic Dome Cover?
   A: Yes, the inner surface of the alumina ceramic dome can be polished or finely ground to a defined roughness to support specific plasma or cleaning requirements.

Customer Reviews for High Purity Alumina Ceramic Dome Cover

• ⭐️⭐️⭐️⭐️⭐️
  We replaced several quartz domes with High Purity Alumina Ceramic Dome Covers from ADCERAX on our hard coating PVD tools. The geometry matched our existing hardware and we were able to extend the planned maintenance interval without changing the coating recipe.
  -- Michael Braun — Process Engineer, SurfaceTech Coating GmbH
• ⭐️⭐️⭐️⭐️⭐️
  Our team needed a fast replacement for an alumina chamber dome cover on a mid-volume etch system. ADCERAX as a ceramic components supplier supported drawing clarification and delivered the High Purity Alumina Ceramic Dome Cover within the agreed lead time.
  -- Laura Chen — Purchasing Manager, NovaVac Systems Inc.
• ⭐️⭐️⭐️⭐️⭐️
  The high purity alumina ceramic dome cover we sourced for a CVD pilot reactor showed stable dimensions and consistent sealing. Custom curvature and flange details followed our specification closely, which simplified installation and qualification.
  -- Kenji Ito — Equipment Engineer, Kyowa Thin Film Centre
• ⭐️⭐️⭐️⭐️⭐️
  Working directly with the ADCERAX factory for High Purity Alumina Ceramic Dome Covers allowed us to standardize dome drawings across several PVD chambers. The domes are stable in our process, and the ability to order small batches for different tools is helpful for our operation.
  -- Robert Miller — Owner, Apex Coating Services