Correlation between Residual Stress and Boron Concentration in Boron-Doped Silicon Films

This paper represents the correlation between the residual stress and the boron concentration in boron-doped silicon films. Residual stress measurement structures of different thicknesses are simultaneously fabricated for the quantitative determination of residual stress profiles. All structures are diffused by various boron diffusion processes and consecutively etched by an improved etch process on the same silicon wafer. The obtained residual stress profiles illustrate that as the drive-in process temperature or the time increases, the average residual stress and the maximum residual stress decrease. For cases of several drive-in process conditions, correlation coefficients between the boron concentration and the residual stress are calculated and the lattice contraction of a boron-doped silicon wafer is measured by high-resolution X-ray diffractometry(HRXRD). The calculated correlation coefficients illustrate that the residual stress profile is closely correlated with the boron concentration after drive-in.