A novel concept and the related testing methodology for a sensing device is presented. This device is used to determine the distributions of local residual stresses induced in wafer processes such as metalization and bumping. The sensing device is essentially a pressure sensor structure with a specified membrane thickness. Either a whole pressure sensor wafer or a single die sensor can be used for this purpose. This sensing device is put into the processes which are under investigation or being monitored. After each processing step, the membrane is deformed due to the process induced residual stress. The membrane deformation is either monitored continuously by the electrical signals from the pressure sensor during the process or measured by an optical method after each process step. Residual stresses are calculated from the measured membrane deformations.

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