Working with nine different foundries

Experience in channeling MMIC designs through processes in several foundries has led the authors to insights into impediments faced by the GaAs industry. Problems affecting chip performance have been due primarily to variables not subject to foundry specifications. These problems include backgating, substrate oscillations, photosensitivity, large-signal discrepancies, and the post-process problems that follow front-side processing. Barring these problems, the cost of chips for high-volume analog applications is most strongly affected by design rules and specification tolerances.<
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