A testing method and device for intrinsic stress measurement in wafer bumping process

A novel concept and the related testing methodology of a sensing device is presented. This device is used to determine the local intrinsic stresses in duced in wafer processes such as metallization and bumping, The sensing dev ice is essentially a pressure sensor structure with a specified membrane th ickness. This sensing wafer is put into the processes which are under inves tigation and is processed together with the production wafers. During the p rocess, the membrane is deformed due to the process induced intrinsic stres s,The membrane deformation is either monitored continuously or measured aft er each process step by an optical method, Intrinsic stresses are calculate d from the measured membrane deformations.