Our wafer stress metrology is unique in our industry. The technology is based on several Ultratech patents for the coherent gradient sensing (CGS) of wafer topography and stress. The interferometric  technology was originally developed by a small team of researchers, working under the business name "Oraxion". In July, 2006, Ultratech, Inc. acquired certain assets of Oraxion.

The team brought to Ultratech the unique ability to measure the stresses induced by laser thermal processing -- a capability not available elsewhere in the industry. Low stress levels are inherently difficult to measure, however by the use of CGS, the Ultratech engineers are able to study and analyze the very low level effects of laser thermal processing.

While both new and unique, this technology has been heavily and successfully applied to practical customer situations. More than 120,000 wafers have been measured using this method, of which more than 20,000 have been measured in Ultratech's own process laboratory. This practical data has led to a deep understanding of the annealing process and optimum means of reducing stress -- unparalleled elsewhere in the industry.