With a growing number of applications for High Brightness LEDs, manufacturers are looking for better strategies to increase yield and improve performance. Today HB-LEDs have made their way into backlighting of notebook computers and LCD televisions, as well as into other diverse applications from cell phones to flashlights to automobile headlights. With legislation targeting the phase out of incandescent lighting and challenging restrictions of toxic materials such as those used in compact fluorescent lighting, volumes of HB- LEDs targeting residential and industrial lighting are likely to expand rapidly in the near future.
As the HB-LED process flow becomes increasingly complex, it drives the requirement for improved control of overlay and critical dimensions in the patterning process. Nanometrics offers a comprehensive line of products and technologies for HB-LED metrology and process control, including the RPMBlue for high-volume production of LEDs used in LCD backlighting, the Vertex PL mapping system to support leading-edge HB-LED process development, and the IVS-185 overlay and CD system for advanced LED patterning process control. The Vertex PL mapping system provides a combination of metrology technologies to support both process development and production control. The Vertex is capable of supporting epitaxial layer metrology on many substrate types and sizes and, due to the illumination system options, can cover the entire spectrum of LED technologies from UV-LEDs through the visible colors to infra-red. Nanometrics’ newest product for HB-LED process control is the RPMBlue, targeted at production control of Gallium Nitride (GaN)-based blue HB-LEDs.