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All sapphire is not created equal. Rubicon’s proprietary crystal growth technology, ES2, and industry-leading capability for slicing and polishing large-diameter sapphire wafers position us as the world’s foremost supplier of sapphire. The quality and purity of Rubicon’s sapphire are unrivaled. Our proprietary ES2 crystal growth technique establishes greater control over crystal growth parameters resulting in a low-stress environment that produces superior quality sapphire. Our state-of-the-art manufacturing facilities fabricate sapphire with precise geometries and orientation and tight tolerances, and our processes are flexible to accommodate a wide range of customer specifications. Rubicon is a fully vertically integrated sapphire manufacturer with technology platforms in crystal growth, high precision core drilling, wafer slicing, surface lapping, ultra flat large-diameter polishing, metrology and wafer cleaning processes. And we continuously develop our technology platforms in anticipation of our customers’ evolving sapphire material requirements.

Raw Material

Rubicon has developed technology to process raw aluminum oxide powder into the intermediate crystal forms required for production of large sapphire boules. High purity alumina powder is sintered, pressed and densified into pellets of various sizes designed to maximize the size of the final crystal boule for any furnace size. This upstream vertical integration sets Rubicon apart by providing greater control of material quality and purity and by reducing our dependence on third parties.

ES2 Crystal Growth

Rubicon's proprietary ES2 crystal growth technology platform, derived from the Kyropoulos method, produces the highest quality sapphire crystals. Our crystal growth furnace design is unique to Rubicon, and we build the furnaces in-house. Our highly automated process is closely monitored by our crystal growth experts to provide consistent high quality and yield. Rubicon’s sapphire boules grow unconstrained in a low-stress environment with a lower thermal gradient than in other crystal growth methodologies. The result is superior quality sapphire with

  • the industry’s lowest etch pit, or dislocation, density (EPD)
  • higher crystal purity (99.996%)
  • high transmission in the UV range
  • best crystalline perfection (by x-ray rocking curve method) in industry
  • best refractive index homogeneity in industry
  • and greater uniformity compared with competing sapphire products, even as size scales up.

Our ES2 crystal growth platform has enabled us to rapidly scale up production of high-volume, large-diameter sapphire at low cost. We are a high-volume producer of six-inch epi-polished sapphire wafers and are fully capable today for high-volume production of eight-inch wafers. We have also demonstrated twelve-inch wafers. As our markets move toward the efficiencies available with larger diameter wafers, superior quality sapphire crystal is more important than ever.

Sapphire Fabrication

Rubicon has industry-leading capabilities in the processing and production of sapphire substrates and optical window products. Our state-of-the art facilities house high-volume production equipment customized for core drilling, slicing, lapping, grinding, cleaning, annealing and measuring sapphire products.  Rubicon grows, fabricates and processes C, R, A, and M-plane sapphire material. We have patented a process for in-situ x-ray orientation maintenance integrated into the fabrication equipment, providing first-pass achievement of the tightest crystal orientation tolerances—just one example of our innovative fabrication technology.

Sapphire Polishing

Rubicon has emerged as the world leader in large diameter sapphire wafers and currently produces six-inch and eight-inch epi-polished sapphire wafers. We produce stress-free, ultra-clean epi-polished wafers with precise orientation, consistent global and local site flatness, including low bow, warp and TTV, meeting the evolving specifications of our customers in the LED, SoS RFIC and optical markets. Superior crystal, dimensional uniformity across the entire substrate and consistency from wafer to wafer facilitate our customers’ epitaxial growth processes and provide them with better chip yields.

Quality Management

Rubicon never compromises on quality, and our processes conform to rigorous, disciplined semiconductor industry manufacturing and quality practices. Our quality management system is compliant with ISO9001:2008, and we employ Six Sigma and continuous improvement methods to establish and maintain a world-class manufacturing infrastructure with well characterized, stable and capable processes.

We employ detailed traceability from raw material to finished product, and the data we collect at each process stage enables our engineers to continuously improve process reliability and yields. Using our highly sophisticated and proprietary metrology platform, we control for orientation, bow, warp, thickness, TTV, dimensional compliance and other customer-specified attributes in finished products.

Customers can expect regular communication with our quality team as part of a productive long-term relationship.

Customer Satisfaction

Rubicon works hard to be your preferred sapphire business partner. As a Rubicon customer, you’ll work with a technical sales team who understands your epitaxial growth and your downstream processes. Our quote process is tailored to suit your requirements and includes all the support you need. And we take pride in our on-time delivery and great customer service. The quality and purity of Rubicon sapphire help customers improve their process yields, and our vertically integrated business model helps us to be the industry’s most reliable source. As customer requirements evolve—and as new applications for sapphire emerge—Rubicon, with its history of successful innovation and its leadership position in the industry, is the logical choice.


Rubicon’s vertically-integrated, state-of-the-art manufacturing facilities leverage our proven ES2 crystal growth technology, high precision core drilling, wafer slicing, surface lapping, large-diameter polishing and wafer cleaning processes to set the industry benchmark. The result: sapphire ingots, windows and substrates in high volume, with superior quality and out-of-the-box consistency, available in the widest range of diameters -- including two-, three- and four-inch core, and large diameter wafers in six-, eight- and 12-inch sizes.

All Rubicon products are precisely designed and manufactured to meets customers’ exacting specifications. Rubicon’s sapphire products are used primarily in markets such as Light-Emitting Diode (LEDs)Silicon-on-Sapphire Radio Frequency Integrated Circuits (SoS RFICs), and Optical applications, including defense, sensor, medical, semiconductor and instrumentation.

Patterned Sapphire Substrates

Rubicon Technology, Inc., the global leader in large-diameter sapphire substrates, has leveraged its unique expertise to create a complete line of Patterned Sapphire Substrates—PSS—in 4” through 8” diameters. Our facility and equipment are state-of-the-art, including our Class 100 clean room and advanced metrology tools. 

We offer fully customizable sub-micron patterning capability with tight dimensional tolerances, within ± 0.1 μm, high-precision control of pattern dimensions, and very high uniformity from wafer to wafer. With an edge exclusion zone as small as 1 mm, Rubicon provides you more usable area to maximize the number of chips per wafer.




Product Specifications




  • ES2 High Purity Sapphire (99.999%)

Crystal Quality

  • Optical Grades
  • No Grain Boundaries, Twins, Lineages, or Crack


  • UV Grade, IR Grade


  • C–Plane (0001)
  • A–Plane (11-20)
  • R–Plane (10-12)
  • M–Plane (10-10)
  • Random

Orientation Tilt Tolerance

  • Customer Preference
  • up to 6” ±0.05
  • up to 8” ±0.10


  • Up to 300 mm


  • Up to 200mm

Surface Finish 

  • As Cored
  • Fine Ground

Available Options 

  • Primary and Secondary Orientation Flats
  • Precision Orientation Off Set 
  • Orientation Notch




Custom Specifications not listed above are also available


Sapphire Ingot is typically used as raw material for further fabrication. Rubicon offers optical grade sapphire ingot, including UV and IR grade. In addition to standard sizes and orientations, orientation offsets and orientation flats are available upon request. Ingots are supplied with surfaces “As Cored” or “Fine Ground” to maximize customer flexibility in final processing.

Product Specifications

Optical Windows


Product Specifications

Optical Windows



  • ES2 High Purity Sapphire (99.999%)

Crystal Quality

  • Optical Grades
  • No Grain Boundaries, Twins, Lineages, or Crack


  • Best UV Grade sapphire in the industry


  • C–Plane (0001)
  • A–Plane (11-20)
  • R–Plane (10-12)
  • M–Plane (10-10)
  • Random

Shape and Sizes

  • Round Up to 12” (300 mm)
  • Square/Rectangle Up to 250 mm Dimensions

Rod Stock Length 

  • Up to 200 mm


  • Up to 50mm +

Surface Finish 

  • Fine Grind
  • Single or Double Side Polished

Available Options 

  • Beveled and Chamfered Edges
  • Radius Corners, Custom Shapes and Features




Custom Specifications not listed above are also available


In optical applications ranging from Defense/Aerospace and Instrumentation to Medical Device and Semiconductor equipment, Rubicon’s ES2 crystal growth and manufacturing technologies provide a full range of sapphire windows of high optical quality and strength, including round windows up to 300 mm or 12 inches in diameter.

Product Specifications

Contact us to inquire about large rectangular windows.

Inquire Here


Epi-Ready Polished Substrates


Product Specifications

EPI-Ready Polished Substrates



  • ES2 High Purity Sapphire (99.999%)


  • None by visual inspection under high
    intensity light

Grain Boundary/Lineage

  • None by visual inspection under Lineage polarized light


  • C–Plane (0001)
  • A–Plane (11-20)
  • R–Plane (10-12)
  • M–Plane (10-10)
  • Random

Orientation Tilt Tolerance

  • Customer Preference
  • up to 6” ±0.05
  • up to 8” ±0.10


  • Up to 200 mm

Flatness (Focal Plane Deviation)

  • Up to 6” ≤4.0 μm
  • Up to 8” ≤6.0 μm


  • Up to 6” 0 ± 15 μm
  • Up to 8” 0 ± 20 μm


  • Up to 6” ≤30 μm
  • Up to 8” ≤40 μm


  • Up to 8” ≤20 μm

Thickness Tolerance

  • Customer Preference
  • ± 25 μm

Surface Finish

  • Up to Ra ≤ 0.2 nm for front side
  • Up to Ra ≤ 1 μm for back side

Orientation Flat/Notch

  • SEMI/JEITA standard

Edge Bevel

  • Industry Standard


  • Surface to be free from all visual contaminants


  • Vacuum-sealed containers with nitrogen backfill in a class 100 environment

Available Options

  • Laser Marking
  • Optical Polished Finish
  • Single Side Epi Ready Finish
  • Double Side Epi Ready Finish



Custom Specifications not listed above are also available


Rubicon’s sapphire epi-polished wafers are ultra-flat, super clean, stress-free large diameter substrates, offered with precision orientations and offsets and wafer-to-wafer uniformity, with one or both surfaces finished. These sapphire wafers are custom designed to meet customers’ unique specifications for final application.

Product Specifications

Consumer Electronics Components

Rubicon supplies sapphire for the consumer electronics market today principally in the form of 2” ingots, which supply chain partners fabricate into double-side polished wafers that can be cut into small circles for camera lens covers and biometric interfaces. We can also make rectangular blocks ready to be sliced  into smartphone faceplates and custom shapes such as smart-watch face plates.


Rubicon’s vertically-integrated, state-of-the-art manufacturing facilities produce six- and eight-inch polished sapphire wafers for the LED industry and for production of Silicon on Sapphire (SoS) wafers for high performance radio frequency integrated circuits (RFICs).

LEDs are widely used in backlighting units for televisions, consumer electronics such as smart phones and tablets, automobiles and a wide range of industrial applications. The adoption of LEDs general illumination, also known as solid-state lighting, is accelerating. SoS RFICs have rapidly gained acceptance in smart phones and other popular consumer devices.

In optical applications ranging from Defense/Aerospace and Instrumentation to Medical Device and Semiconductor equipment, Rubicon’s proven ability to deliver optical quality sapphire in a wide variety of shapes has positioned the company as the supplier of choice to discerning manufacturers worldwide.





Crown Fountain at Millenium Park—Chicago


Sapphire is the predominant substrate material used to produce a vast majority of all blue, white, green and UV LEDS. The list of applications for LEDs continues to grow, with increasing demand for LEDs in the high-volume/high-demand consumer electronics and general lighting industries in products such as light bulbs, large displays, traffic lights, HDTVs, tablets, netbooks, computer monitors, gaming systems and mobile phones.

With their environmentally-friendly, durable and energy efficient properties, Light Emitting Diodes (LEDs) are the future of lighting. And large-diameter sapphire is the future of LED manufacturing. The advantages of large-diameter sapphire in this market are clear – manufacturers achieve greater throughput with more useable surface area on larger substrates, losing less area around the edges and realizing operational efficiencies. LED manufacturers in all markets realize that continued growth hinges on improved performance and reduced cost.

Sapphire is to LEDs as silicon is to microprocessors, and Rubicon is the acknowledged worldwide market leader in sapphire for LEDs – and produces and delivers more large-diameter sapphire than any other vendor. Our proprietary ES2 crystal growth technology and end-to-end manufacturing and fabrication capability enables us to deliver customized products to meet our customers' exacting needs. Rubicon offers sapphire ingot and sapphire wafer products for LED production.


Sapphire is used as the substrate in the production of Silicon-on-Sapphire (SoS) wafers used in the production of high-performance radio frequency integrated circuits (RFICs). Mobile devices, smart phones and other electronics benefit from SoS RFICs through reduced energy consumption, improved performance, and smaller form factors – as compared to less efficient RFIC technologies.

SoS RFICs are produced on larger-diameter R-plane sapphire substrates and offer a more environmentally-friendly alternative to arsenic-based Gallium Arsenide (GaAs) wafers. Rubicon Technology provides six- and eight-inch polished sapphire wafers for production of SoS RFICs, with other sizes available upon request.

Optical Markets


Sapphire UV and IR transmission properties in combination with ability to withstand harsh chemicals, high pressures and temperatures offer strong advantages for Fire and IR Detectors, protective windows and thermocouple protection sheaths for remote sensors and optics for harsh environments such oil well drilling, chemical processing and other industrial processes.


Polished windows or ground blanks available up to 300 mm diameters. Various shapes and sizes available.


Ground or polished rods up to 300mm lengths and up to 50 mm diameters.


Sapphire’s durability and resistance to fluorine chemistries and high temperature process environments up to 2,000°C offer advantages over other materials such as quartz, alumina and other ceramics. Sapphire often replaces these materials in process chamber environments. Key products include:


Available in many shapes and size in dimensions up to 250mm x 325mm and diameters up to 300mm.


Sapphire rod shaped and ground to customers specifications.


Tubes up to ~2” OD and 12+” lengths finished to tight tolerances.


Available in diameters up to 300mm and thickness up to 100mm.


2”, 4”, 6” and 8” wafers available with ground or polished surfaces and custom thicknesses.


Sapphire's chemical resistance, and ability to withstand high temperature and high pressure, and ability to transmit in UV and IR ranges make it ideal for applications such as mass spectrometry, spectrophotometry, digestive cells, and other analytical applications. Sapphire often replaces quartz and glass to improve equipment and consumables lifetimes. Key products include:


Round, square, rectangular windows available in customer thicknesses and sizes in both UV and IR grades.


Small and large sapphire tubes with one or both ends capped or plugged. Dimensions up to 1” OD and 12” lengths available.


Sapphire's optical transmission range, durability, ability to be shaped into sharp edged products and inertness with human tissue offer advantages for specific medical laser applications for dermatology, ophthalmology and dentistry. Sapphire products are also used for surgical tools, implants, braces and in a variety of windows for medical equipment such as endoscopes and laser windows. A variety of polished windows, shaped parts and blanks available.


Sapphire is used due to its broad transmission range in the UV through IR spectrum, resistance to scratching and corrosion in sand or salt environments and its impact resistance. Key Defense and Aerospace applications include Targeting Systems and Protected Optics for fighter jets, UAVs and Helicopters, FLIRs and Enhanced Vision Systems for aircraft, Sensor Suites and Shaped Optics for land, air and sea vehicles, Missile Domes, Countermeasure Lamps and Transparent Armor Systems. Key products include:


For targeting systems, FLIRs, UAVs, sensor suites, optics and armored windows. Circular windows with dimensions of up to 12" diameter, 10" x 14" rectangles with thicknesses up to 2" or greater.


Diameters up to ~2" and lengths up to 12+" for counter measure lamps and optical light pipes and sensors.

Our LANCE project is setting a new standard in very large area, high quality sapphire.

Sapphire is ideal for high-performance optical applications due to its physical properties. Sapphire offers optical transparency, physical strength, resistance to abrasion and corrosion, temperature durability, chemical inertness, and bio-compatibility. Rubicon’s capability to produce multiple shapes and products such as very large size sapphire windows and blanks of excellent optical quality and strength help expand the range of applications available to our customers to utilize high-performance sapphire parts.

Key Optical market segments for sapphire include:

Consumer Electronics

Sapphire is emerging as a highly desirable scratch-proof material for the exterior of smartphones, smart watches, and other consumer electronic devices. Sapphire has excellent touch capacitance and display clarity, and because of its single-crystal nature may have other benefits for phone manufacturers as well.  Since the introduction of sapphire lens covers for the cameras of certain phones in 2012 and the sapphire-covered home button for fingerprint recognition in 2013, sapphire has been a hot topic in consumer electronics. The volume of sapphire required for camera lens covers provided a small but noticeable increase in global sapphire demand; the amount required for high-volume face plates would require additional dedicated capacity. Sapphire is more costly than the glass typically used in these applications today, mainly because sapphire’s hardness makes the cutting and polishing expensive.  Rubicon is working on innovative, cost-effective, solutions that would drastically reduce fabrication costs. 

See our products for the consumer electronics market

Research & Development

Rubicon has a strong track record of developing new technologies and processes to lead our markets and provide a constant stream of new products. Our material scientists, crystal growers and experienced engineers, many with PhD-level training, work closely with our customers to provide innovative products and solutions to meet their demands. We understand customers’ applications and can develop optimal custom solutions.

We continue to focus our R&D efforts on growing larger dimension sapphire crystals and increasing the capability of our fabrication processes to provide innovative crystal products and improve our customers’ yields and throughput. In addition, we apply our expertise to develop proprietary manufacturing and metrology processes to ensure that we remain the world’s most capable and trusted sapphire supplier.

Project LANCE: Very Large Sapphire Windows

Sapphire’s Physical Attributes

Sapphire is a desirable material for military and other high-performance applications due to its hardness and strength, transparency in the visible and infrared (IR) spectrum, thermal conductivity, thermal shock resistance, abrasion resistance, high melting point and chemical inertness. As a result, it is ideally suited for IR windows in extreme environments where material durability is just as important as optical clarity.

Sapphire is used as a component in semiconductor wafer processing equipment because of its hardness, chemical inertness, and durability even at elevated operating temperatures. The semiconductor industry has moved to 450 mm (18”) wafers and there has been no sapphire product available with the required dimensions, so other, less durable, materials have been substituted. We expect that Rubicon’s LANCE sapphire, when commercially available, will meet a need in this market.

As military sensor technology continues to advance, so too does the demand for sapphire windows capable of withstanding the harsh environments where such sensors are required. Rubicon has developed an entirely new sapphire crystal growth platform capable of growing very large, thick windows – 14 x 20 x 1.5 inches – of optical quality sapphire for military sensing applications.

Previous growth technologies that produce large-area sapphire crystals are incapable of generating the thickness required for demanding defense applications; Rubicon expects to grow panels two inches thick. Supported by a contract from the Air Force Research Laboratory, Manufacturing and Industrial Technology Division, Rubicon will scale production to meet the current and future requirements of the Air Force, progressing to windows as large as 36 x 18 x 0.8 inches.

Initial applications for this product will include supersonic aerospace systems that require protective windows able to maintain excellent transmission characteristics in the visible and IR range and to protect onboard imaging systems. Additional military protective applications for large sapphire windows—as well as commercial and industrial applications—are also likely to arise. (more)


Sapphire’s Physical Attributes

A likely commercial application of very large sapphire panels
is in semiconductor manufacturing equipment. (more)

200kg Sapphire Boules

What’s beyond the six-inch sapphire wafer? Rubicon has production capability for eight inch wafers today, and with these 200-kg boules, we are advancing to 12-inch sapphire substrates.

Just as the semiconductor industry got its start with two-inch silicon wafers back in the 1960s and has now scaled up to twelve-inch (300 mm) wafers, there is a parallel trend in sapphire substrates for LEDs and other electronic applications. Larger wafers provide significant efficiencies in MOCVD reactor processing, providing much greater throughput per reactor run, reducing edge loss, and taking advantage of available back-end processing equipment.




A 200-kilogram boule of 99.996% pure sapphire >