X-ray residual stress measurement of aluminum thin films with [111] fiber texture
Tanaka Keisuke; Ishihara Keisaku; Inoue Kaoru
Abstract:A new method of X-ray stress measurement was applied to the measurement of residual stress in aluminum thin films sputtered on (100) oriented silicon single-crystal wafers. The film has the [111] fiber texture perpendicular to the film surface. The strain was measured from Al 222 and 311 diffractions obtained by Cr-K a radiation. The values of in-plane residual stresses s11, s22 and s12, and out-of-plane normal residual stress, s33 were determined from the measured strains by using the fundamental formulae derived on the basis of Reuss and Voigt models. The residual stress in the thin films was nearly equi-biaxial tension, and its magnitude decreased with increasing film thickness. The residual stress determined by the curvature method was nearly equal to the value determined by the X-ray method. Key Words:Z-ray stress measurement, thin film, cubic crystal, fiber texture, Reuss model, Voigt model, X-ray elastic constant, residual stress