Recycling Processed GaAs Wafers
Martin J. Brophy, TriQuint Semiconductor
Luc Legratiet and Gerard Gilles, Picopolish, Chemin des Chapons des Prés

Over the last several years, we have developed processes for strip-back and re-polish of process-monitor wafers as well as scrapped GaAs wafers from all points in the various TriQuint fabrication flows. Initial efforts produced several thousand mechanical grade wafers with high yields. Current processes produce prime wafers that meet all the TriQuint GaAs substrate specification criteria. These have been shown in initial production fabrication run trials to work generally as well as virgin GaAs wafers. The obstacles overcome in this development will be discussed and production lot electrical data will be presented to demonstrate the value of this promising and frugal workaround to the current worldwide wafer shortage.