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

This paper presents a quantitative method to determine the profile of the residual stress along the depth of a highly boron doped silicon film. 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. Secondly, 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 p⁺ region is subjected to the tensile stress except the region near the front surface and the average stress is 50 MPa.