All semiconductor wafers must undergo an etching process which chemically removes layers from the surface of a wafer. The etch rate must be precisely controlled through chemistry, time, and tight temperature control. A manufacturer had a new etchant which relied on a higher than normal temperature control profile. It was critical for this manufacturer to have superior control in this new temperature sensitive etching chemistry. - Due to the enhanced temperature control of their new etching process the customer realized a 68% decrease in rejects due to a reduction in temperature related undercut. Before, this undercut manifest itself as isotropic (sloping walls) as opposed to the current desirable anisotopic profile (straight wall).

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