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Sapphire Window & Optical Flat
Sapphire Window & Optical Flat

Sapphire

Sapphire Window & Optical Flat

Single-crystal sapphire windows and optical flats for semiconductor process chambers, optical monitoring, and high-temperature applications, with specifications reviewed case by case.

Material: Single-crystal Al₂O₃; grade confirmed by material source Crystal Orientation: C-plane (0001) standard; A, R, M-plane available Surface Roughness: Specified per optical requirement Surface Form: Reviewed case by case

Custom dimensions and specifications available upon request.

Technical Specifications

Parameter Value
Material Single-crystal Al₂O₃; grade confirmed by material source
Crystal Orientation C-plane (0001) standard; A, R, M-plane available
Surface Roughness Specified per optical requirement
Surface Form Reviewed case by case
Transmission Range Depends on grade, thickness, and wavelength
Max Use Temperature Application-dependent

Sapphire Window & Optical Flat

Sapphire Window & Optical Flat 2
Sapphire Window & Optical Flat 3
Sapphire Window & Optical Flat 4

Sapphire Windows & Optical Flats

Sapphire windows are used where fused quartz may be inadequate, such as plasma-intense environments, high-temperature applications, or projects that require broader optical transmission for pyrometry or spectroscopy. Final material suitability should be reviewed against the operating environment and mounting design.


Material Advantages Over Fused Quartz

PropertyFused QuartzSapphireSelection Note
HardnessLower than sapphireVery high hardnessSapphire may be preferred for wear or plasma-facing use
Temperature exposureApplication-dependentApplication-dependentReview mounting and thermal-cycling conditions
Mid-IR transmissionLimited by grade and thicknessBroader range possibleConfirm wavelength, thickness, and surface finish
Chemical resistanceStrong for many processesStrong for many processesReview chemical concentration, temperature, and exposure time
Surface finishPolishing availableOptical polishing availableSpecify flatness, roughness, and inspection method

Standard Window Specifications

Unmounted Sapphire Windows

SpecificationStandardPrecision
Diameter tolerancePer drawingReviewed for critical dimensions
Thickness tolerancePer drawingReviewed for critical dimensions
Surface roughness (both faces)Specified by applicationReviewed with measurement method
FlatnessSpecified by applicationReviewed with inspection method
ParallelismSpecified by applicationReviewed with inspection method
Scratch-digOptional specificationReviewed for optical-grade orders
Crystal orientation accuracyOptional specificationVerification can be discussed when required
CoatingBare window standardCoating requirements reviewed case by case

Crystal Orientation Options

OrientationBirefringenceBest For
C-plane (0001)Zero (z-propagation)General windows, LED substrates
A-plane (11-20)Max birefringenceSpecialized optical applications
R-plane (10-12)IntermediateHeteroepitaxy substrates
M-plane (10-10)IntermediateSpecialized semiconductor
Custom off-axisPer specCustomer-specified optical axis

Crystal orientation verification and related documentation can be discussed when the application requires a specified orientation.


Optical Transmission Data

Wavelength RangeReview Note
UVConfirm grade, thickness, surface finish, and inspection method
Visible / NIRConfirm wavelength band and transmission requirement
Mid-IRConfirm wavelength, thickness, mounting, and thermal conditions

Typical Applications

  • Plasma chamber viewports — resist plasma erosion where quartz would fail
  • Pyrometry windows — mid-IR transmission requirements reviewed by wavelength and thickness
  • Laser processing windows — optical and damage-threshold requirements reviewed case by case
  • High-temperature reactor viewports — RTP and epitaxy applications reviewed against mounting and thermal cycling
  • Wear-resistant covers — wherever mechanical abrasion would damage quartz

Ready to order or need a custom size?

Submit your drawing or specifications — we respond within 24 hours.