SEMI HB-LED Standards Activities Update - April 2011

SEMI HB-LED Standards Activities - Update April 2011

Paul Trio, Senior Manager, NA Standards Operations

The SEMI North America (NA) HB-LED Standards Committee met on March 31 in conjunction with the NA Standards Spring 2011 meetings in San Jose, California.  The all-day event was held at SEMI Headquarters and included meetings of the committee’s three chartered task forces: Wafer TF, Equipment Automation Interfaces TF, and Assembly TF.  Prior to the NA Spring meetings, the HB-LED task forces met in conjunction with the Strategies in Light Conference (February 23, 2011) in Santa Clara, CA.

Wafer Task Force
The HB-LED Wafer Task Force was chartered to define physical geometry of wafers used in HB-LED manufacturing starting with 150 mm diameter sapphire wafers.  From its initial meetings, the task force agreed to address the following wafer characteristics:

  • Diameter
  • Center Point Thickness
  • Total Thickness Variation (TTV)
  • Bow & Warp
  • Orientation Fiducial
  • Wafer ID
  • Wafer Edge Shape

Then in early March, the task force deployed a survey to gather industry inputs on these identified priorities.

The task force reviewed the preliminary survey results at the NA Spring meetings which included responses from sapphire wafer producers/growers, equipment suppliers (including MOCVD tools), and end users.  Wafer marking locations (i.e., top, bottom, and edge) were discussed in detail and how these markings fare during wafer processing.  The Wafer TF also explored how the edge chamfer would be best specified in the standard and whether orientation fiducials would entail notch dimensions or include flat as well.

SEMI will continue to solicit additional inputs, particularly from end users in other regions.  SEMI HB-LED committee members, representing equipment supplier companies, will invite their customers to participate in this survey also.

Equipment Automation Task Force
The scope of the Equipment Automation Task Force includes the development of both software and hardware requirements for the HB-LED manufacturing automation system.

For automation software, presentations were provided on the benefits of Equipment Data Acquisition and how it compares to (and possibly complement with) SECS/GEM implementation.  Aixtron also presented on existing SEMI Standards (e.g., SEMI E5, SEMI E30, SEMI E37/E37.1) currently used on MES interfaces for MOCVD equipment, but also emphasized the need for additional SEMI Standards for future fully automated tools:

  • Process Job and Control Job Management
  • More complex Wafer Tracking in Cluster
  • Tracking flow & status of Process Trays
  • Data exchange with OHT for automated Cassette Exchange
  • Support for Advanced Process Control
  • Support of Interface A (EDA)
  • Data Communication from Insitu / Inline measurement tools to MES / EES
  • Protection against virus attacks & misuse of data

With regard to physical interfaces/hardware automation, the task force developed a preliminary list of components that it believes must be standardized:

  • Cassette
    • Open Cassette
    • Process Tray Cassette
  • Automated Pod
  • Minienvironments
  • Load Port
  • OHT
  • Automated Tracking
    • Cassette/Wafer
    • Process Tray (mark)
  • Shipping Carrier

The task force also began to itemize the critical features that need to be considered for each component.

As discussions become more detailed and specific to software or hardware requirements, the task force created two working groups which will meet separately (via teleconference) in the next several weeks.  All interested parties are invited to participate in these working groups.

Assembly Task Force
The goal of the Assembly Task Force is to identify opportunities where the establishment of standards would:

  • Lower costs of assembly
  • Improve inter-operability among assembly steps or processes
  • Increase potential for multi-sourcing assembly equipment, materials, or services
  • Improve efficiency of assembly / packaging
  • Increase yields and/or predictability and repeatability of assembly process steps

The task force plans to deploy a survey to gather industry inputs on the biggest cost drivers of HB-LED assembly and packaging.  The survey aims to identify possible problems in areas such as: fixturing; materials; handling systems; dimensions (die, package, footprint, length); optical or vision systems; compliance with specs.  The draft was reviewed at the NA Spring meeting with plans to deploy as soon as possible once the questionnaire is finalized.

Considerations for HB-LED / Environmental, Health & Safety (EHS) Standards Development
The committee discussed establishing a standardization activity with regard to safety technology in fabs for III/V process operation.

The silicon industry is researching on GaN and other III/V layers on silicon according to their material development roadmaps.  This means that MOCVD process modules have to be integrated into silicon fabs.  However, different technical understanding of safety technology exists on silicon customer side and MOCVD tool vendor side.  The Si-customers will mostly request a MOCVD system integration in their Si-fabs according SEMI safety standards (EHS) which have been created for standard Si-process modules.  However, there is a request for a higher safety level for the integration of the MOCVD tools in the Si fabs. This higher safety level is requested depending on the used III/V precursor materials and gases which are highly toxic, corrosive and explosive. The different technical understanding in field of a safe MOCVD tool integration in Si-fabs will cause a lot of conflicts and problems that need to be clarified during each project and will cost a lot of efforts on both sides.

The co-chairs for the HB-LED and EHS committees will discuss on how best to establish this standardization effort including which committee(s) the task force(s) will be established.

NA HB-LED Standards Meetings at SEMICON West 2011
The next NA HB-LED Standards meetings will take place on Thursday, July 14 in conjunction with SEMICON West 2011 in San Francisco, California.  The HB-LED and other SEMI Standards meetings will be held at the San Francisco Marriott Marquis Hotel, one block away from the Moscone Convention Center.

Join Today!
If your company is involved in manufacturing HB-LEDs, this is your opportunity to get involved and participate in developing the standards that will affect your company. For additional information on the HB-LED Standards Committee and its task forces/working groups; or how to join the Committee, please contact Paul Trio at ptrio@semi.org.