Optical Metrology of Patterned Sapphire Substrates for HB-LEDs

High-brightness light emitting diodes (HB-LEDs) are mostly formed on sapphire wafers. Patterning the substrates with tiny structures ensures a drastic improvement in the light extraction efficiency of the completed device. PSS wafers also solve critical issues that include crystal dislocations and refractive index mismatch.

The Zeta-PSS Package offers quick characterization of substrate bump features. Height, width, and pitch are determined in the same scan. Recipes are available for all types of substrate bumps that include cone-shaped, dome-shaped, flat-topped, or photoresist.

Zeta Optical Profile System

The Zeta Optical Profiler System includes the following salient features:

  • Automated feature analysis
  • Exceptional measurement potential

Automated Feature Analysis

This feature is easy to use and production-ready and is capable of the following:

  • The Zeta Optical Profiler takes a large area scan (70 µm x 90 µm) in seconds.
  • Using the Zeta 3D software, a one-page analysis report can be obtained that includes 2D and 3D images, a cross section, and statistical analysis of all features in the field of view.
  • Numerical results are saved in spreadsheet-friendly text format.
  • Automated X-Y stage and multisite recipes allow characterization of the entire wafer.

Exceptional Measurement Capability

Zeta Optical Profiler measurements of height and width correlate well with those obtained with the AFM.

Optional Piezo Z stage provides 2nm Z-height resolution and 3s repeatability below ±15nm

The specific features and options of the Zeta-PSS Package include the following:

  • Manual load system for R&D and automated XY stage for production
  • Vacuum chucks for wafers of different sizes
  • Vibration and Environmental noise isolation package Piezo stage for 2nm height resolution
  • True color 3D imaging enable review of defects such as scratches or missing bumps

Zeta 3D Software analyzes standard 2D or 3D wafer images for general surface characterization:

  • Step height
  • Surface roughness
  • Feature size, diameter, area, and volume
  • Wafer bow
  • 3D surface visualization in true color
  • Statistics

Zeta 3D Optical Profiler with piezo stage & 2” wafer chuck

Zeta 3D Optical Profiler with piezo stage & 2” wafer chuck

Customized PSS analysis software includes production-ready recipes for cone, dome, and flat-topped bumps. Hardware includes Zeta’s unique PSS specific illumination optics.



This information has been sourced, reviewed and adapted from materials provided by KLA Corporation.

For more information on this source, please visit KLA Corporation.



Please use one of the following formats to cite this article in your essay, paper or report:

  • APA

    KLA Instruments™. (2023, April 12). Optical Metrology of Patterned Sapphire Substrates for HB-LEDs. AZoNano. Retrieved on June 25, 2024 from https://www.azonano.com/article.aspx?ArticleID=2937.

  • MLA

    KLA Instruments™. "Optical Metrology of Patterned Sapphire Substrates for HB-LEDs". AZoNano. 25 June 2024. <https://www.azonano.com/article.aspx?ArticleID=2937>.

  • Chicago

    KLA Instruments™. "Optical Metrology of Patterned Sapphire Substrates for HB-LEDs". AZoNano. https://www.azonano.com/article.aspx?ArticleID=2937. (accessed June 25, 2024).

  • Harvard

    KLA Instruments™. 2023. Optical Metrology of Patterned Sapphire Substrates for HB-LEDs. AZoNano, viewed 25 June 2024, https://www.azonano.com/article.aspx?ArticleID=2937.

Ask A Question

Do you have a question you'd like to ask regarding this article?

Leave your feedback
Your comment type

While we only use edited and approved content for Azthena answers, it may on occasions provide incorrect responses. Please confirm any data provided with the related suppliers or authors. We do not provide medical advice, if you search for medical information you must always consult a medical professional before acting on any information provided.

Your questions, but not your email details will be shared with OpenAI and retained for 30 days in accordance with their privacy principles.

Please do not ask questions that use sensitive or confidential information.

Read the full Terms & Conditions.