Bulk Ammonia Supply Solutions for LED Manufacturing
Robert
W. Ford, Bulk Specialty Gas Mgr., Electronics Division
Air Products & Chemicals, Inc., 7201 Hamilton Blvd., Allentown, PA 18195
Email: Fordrw@airproducts.com Phone
Tim
Conway, NH3 Technical Program Coordinator, Global Engineering Organization,
Air Products & Chemicals, Inc.,
Email: Conwayte@airproducts.com Phone:
Large volumes of Ammonia (NH3) gas are needed to provide the nitrogen source for the gallium nitride layers in the manufacture of LEDs. The traditional approach is to use standard 1.5 ft3 or 47 liter cylinders inside gas cabinets. As NH3 volumes increased for newer process tools, cylinder supply became impractical. Flow rates were severely limited; the thermodynamic issues causing cooling of the cylinders, requiring their change out at more frequent intervals plus the quality of the ammonia was impacted. Bulk Specialty Gas Supply (BSGS) overcame the many challenges that cylinders in gas cabinets have presented. BSGS uses larger NH3 source containers fed to a high flow delivery system that is piped to the process tools, analogous to bulk liquid N2 installations. Many LED manufacturers have embraced the BSGS concept. However, LED manufacturers that have taken an incremental approach may still have issues with flow rates, purity, and reliability. A Total Solutions approach is required that addresses the essentials to ensure reliable NH3 supply. These elements include large-scale NH3 purification, packaging, and QC, a proven record of integrated bulk delivery system design, with commercial options including on site operations and maintenance. This presentation addresses the basis of bulk high purity NH3 supply, and dispels some myths, in order to demonstrate the best overall NH3 total Solution to LED manufacturers.
Keywords: Ammonia, Bulk Specialty Gas Supply