GT Advanced Technologies has released a case study of evaluating the impact of sapphire color on the LED manufacturing process.

All studies were conducted using blind samples of GT ASF sapphire material as well as LED grade sapphire from other sources. The case study results were obtained from an independently conducted Glow Discharge Mass Spectroscopy (GDMS) analysis as well as a High Brightness (HB) LED device fabrication study performed using Photo-thermal Common-path Interferometry (PCI) analysis.

The studies demonstrated that all sapphire, regardless of source, exhibits color at the core level, that the pink hue of GT Advanced Sapphire Furnace (ASF™) material is not indicative of impurities, and that pink ASF sapphire does not have an adverse affect on the LED manufacturing process nor does it require extra steps or incremental costs to remove the pink hue. In addition, it was demonstrated that GT ASF pink sapphire material makes the lowest absorption, highest transmission epi-wafers of the samples examined.

The new study is part of a larger comprehensive material characterization project initiated by GT to examine the effects of sapphire material properties on the entire manufacturing processes in the HB LED value chain. The company will present the findings of the color case study at the GG LED Conference, December 9-10, in Shenzhen, China.