Measurement technique for the evaluation of residual stress in epitaxial thin film by asymmetric X-ray diffraction

An analytical technique to determine residual stress in eqitaxial thin sim by asymmetric X-ray diffraction (XRD) was studied. The residual stresses of PbTiO3 films were determied by XRD technique and displace measurement tech nique. Measurement results by these techniques were compared with each othe r to consider the respective advantages of each technique, The stresses mea sured by XRD technique There not consistent with those by displacement meas urement technique, because the latter technique involves errors which origi ned from the shape and the size of the substrate. The stress in a polycryst alline film measured by modified sin(2)psi method was in good agreement wit h that measured by normal sin(2)psi method. This result suggests that modif ied sin(2)psi method can be applied to stress measurement not only in epita xial thin films, but also in polycrystalline thin films, We further discuss the precision of the stress determination technique. Residual stress of ep itaxial PbTiO3 him on (100) SrTiO3 substrate measured by modified sin(2)psi method was comparable to the theoretical stress estimated from the differe nce in thermal expansion coefficients between the film and the substrate. S tress values measured by modified sin(2)psi method may thus have the precis ion required for actual application.