The quantitative deterrnination of the residual stress profile in oxidized p÷ silicon films

This paper presents a quantitative method to determine the profile of the residual stress through the depth nf a highly boren-depod silicon film. First, the stress profile relative to the stress at the neutral surface of the film is determines by least-square estimation using the measured vertical deflection of p+ silicon cantilevers with different etch depths. Secondly, the average of the residual stress is obtained from the measured deflection of a rotating beam stmetare. The slress profile is determined completely from these two 6 :terminations. Two example, s for the application of this method illustrate that most of the p ÷ region is subjected to the tensile stress exeel~ th¢~" region near the front surface and that the stress gradient of the film oxidized at 1100 *C is steeper than theft of the fiim oxidized at 1000 °C. Keyword~: Residual stress; p* siE¢on films; Catdilevers; Rotating beam stnletures