Sapphire On Quartz

Synthetic sapphire and fused quartz are both used in optical applications requiring extreme heat resistance, exposure to fluorine plasma, and transmittance in UV, visible & IR spectral regions. However, solid sapphire is difficult and costly to process, and uncoated quartz can degrade in harsher environments at a rate requiring frequent part replacement. 

We now offer a hybrid solution, a sapphire-coated quartz version of the original uncoated part that can be substituted for either; this design boasts an etch rate in CF4 approaching sapphire, but with pricing closer to quartz. Less frequent part replacement increases up-time and saves money.  We offer sapphire-coated quartz windows, sapphire-coated tubes, sapphire coated heater windows, sapphire-coated quartz parts with complex geometries as well.

Sapphire-On-Quartz (SOQ) can be the original design for many existing semiconductor tools; in other cases, an SOQ version is an upgraded or more cost-effective version of a simple quartz or sapphire part. Host hardware and fixtures typically require no retrofitting to accept SOQ parts.

Sapphire On Quartz

Features & Benefits

  • Why Sapphire On Quartz
    • Single or double side coating available; coated side marked per customer preference
    • CF4 etch rate approaching that of sapphire
    • SOQ parts can last as much as 5 - 10X longer than uncoated quartz parts
    • No delamination of sapphire coating in plasma environment over time
    • Custom fixturing may be necessary for complex or new designs
    • Can coat the outside surface of tubes
  • Sapphire On Quartz Coating Options
    • Complete sapphire-coated quartz finished parts are available; from short-run, prototype quantities to full production volume capacity
    • Sapphire-coated windows, sapphire-coated viewports, sapphire-coated tubes, sapphire-coated heater windows
    • Sapphire coating can also be applied to customer-supplied bare quartz parts and substrates, provided as a service. 
    • Dedicated buffer stock is available upon request
  • Why S & D Materials
    • S & D offers all 3 solutions; sapphire, quartz, and SOQ; best option is always available to meet customer needs
    • Kit pricing available – we can coat an entire package of parts and price it by the kit
    • Stock of quartz parts maintained to minimize lead times for sapphire coated upgrades
    • Large coating chamber allows for various shapes and sizes 
    • Cost savings analysis support available for determining candidacy and impact of sapphire coating

Specifications & Data

Etch Rate



  1. EXISTING DESIGN - If the original OEM design is already SOQ, we can produce standard SOQ parts from a drawing, an OEM P/N, a description or sample part
  2. REDESIGN - If the current design is uncoated quartz or solid sapphire, we can offer options and provide guidance on redesigning as an SOQ part
  3. NEW DESIGN - If a new part is being designed or still in development, our design consultants will explain the SOQ process, outline any challenges, and provide recommendations as requested. 


  • Can coat rounds up to 18” or more in diameter 
  • Custom fixturing available for new designs
  • Al2O3 can be coated on the outside surface of tubes
  • Al2O3 coating is not single-crystal, not applicable for optical applications


  • Are complicated geometries necessary for basic functionality?  Can some surfaces be left uncoated?  Simpler parts have a lower total cost.
  • Quartz quality and cleanliness affect coating quality.  Details on surface finish and cleanliness should be included in the RFQ or part description.
  • Clearly considering and marking on drawings which surfaces need to be coated and which do not can significantly impact coating lead time and pricing.
  • Different plasma chemistries can require different coating solutions. Consulting with S & D Materials can ensure that you're provided with a solution that meaningfully lengthens product life for your specific situation.

Applications and Industries

Sapphire On Quartz Part Applications / Uses
Round Window Heater window
End point window
Inspection window
Ring, collar, plate Chamber component
Radio transmssion, energy storage
Tube MW Plasma Etching
Laser / illumination systems
Containers, elements
Rod / Pin / Ingot Guide Pin, Lift Pin for wafer mfg
Semi Mfg. Chamber Component
Industrial component
Dome UAV Camera Cover
Optics in harsh conditions
Protective optical housing (POH)
Custom Designs, 3D 3D Printing, Extreme imaging
Industries & Markets
Semiconductor Mfg, Consumer Electroncs, Power & Energy, Defense & Aerospace, Medical, Electronics

Contact Info

S&D Materials, LLC.
39 South Main Street Suite 222
Rochester, NH, 03867 USA

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