With the help of DOE funding, KLA-Tencor is developing an improved inspection tool for LED manufacturing that promises to significantly increase overall process yields and minimize expensive waste. The power of the inspection tool lies in optical detection techniques coupled with defect source analysis software to statistically correlate front-end geometric anomalies in the substrate to killer defects on the back end of the manufacturing line, which give rise to an undesirable or unusable end product.

The project is based around KLA-Tencor's Candela inspection technology and includes the successful realization of several significant technical enhancements that have improved defect sensitivity on industry-standard sapphire substrates and enhanced the sensitivity to the yield-limiting surface pits and micro-cracks that are often present on epitaxially grown LED wafers. The new tools are currently being used by a number of key manufacturers as part of the project evaluation stage.

One such test site is Philips Lumileds, where the KLA-Tencor tool has been an important part of efforts to increase yield and reduce cost, and an important element in Philips' recent process ramp from 75mm to 150mm sapphire substrates. Results such as these encouraged KLA-Tencor to announce in January 2011 the release of this new model as the Candela 8620. The introduction of this new inspection tool and associated yield-management package into both R&D and manufacturing operations will accelerate the realization of significant cost savings in the manufacturing of LED packages for SSL. This project received funding under the American Recovery and Reinvestment Act.