A technique for quantitative determination of the profile of the residual stress along the depth of p⁺ silicon films

A quantitative method to determine the profile of the residual stress along the depth of a highly boron doped silicon film is reported. First, the stress profile relative to the stress at the neutral surface of the film is obtained by measuring deflection of p⁺ silicon cantilevers with different etch depths. Second, the average of the residual stress is obtained by using a rotating beam structure. The stress profile is determined completely from these two calculations. One example of application by this method illustrates that most of the p⁺ region is subjected to the tensile stress except for the region near the front surface.