SEMI International Standards
Date Prepared: 08/17/2016
Revised (if Applicable):

Name of Task Force (TF): Patterned Sapphire Substrate Task Force

Global Technical Committee: HB-LED
Originating Technical Committee Region: China

1. Charter: (State the objective of the proposed TF.)
Recently, development of III-IV nitride represented by GaN, has contribute significantly to the solid-state (SSL) lighting development. Sapphire substrate is now widely used as substrate of III-IV group nitride in LED. Due to the lattice mismatch and the difference in coefficient of thermal expansion between nitride and sapphire substrate, the sapphire substrate may impact luminous efficiency and lifetime of LED device. While, Patterned Sapphire Substrate(PSS)can effectively solve these problems. This makes it getting extensively used in LED devices manufacturing.
However, with the development of technology in the field of LED and rapid growth of this industry, the requirement for PSS on GaN-based LED device is getting higher than before. Any change in that parameter of PSS may lead to directly impact reliability of LED devices. So far, every PSS manufacturer has its own understanding of characteristics and definition, which has brought a lot of confusion to the LED device manufacturing process.
Establishing TF for Patterned Sapphire Substrate (PSS) can effectively boost to the development of LED device.

2. Scope: (Define the specific activities that the TF will conduct.)
This TF activity will focus on provide the standards on:
1. Definition of terms needed for characterizing of PSS and measurement procedure
2. Develop standard techniques and methods to review shape, geometries, uniformity and defects for PSS.
3. Provide standard classification procedures and guidelines to differentiate grades of PSS.
4. Developing post-etch PSS structure geometry definitions and metrology useful for process development, monitoring and yield analyses.

3. Formal linkages with TFs in other Regions/Locales: (Show each associated TF and its parent global technical committee; indicate nature of relationship – global TF, observer TF, etc.)
HB-LED Committee NA Chapter Patterned Sapphire Substrate (PSS) TF
4. Formation Date:(TF formed on)

Task Force formed on: 08/17/2016
Task Force approved by Committee/GCS on: 10/14/2016