Macroscopic residual stress in chemical-vapor-deposition free-standing diamond films by x-ray diffraction analyses

We present a structural analysis of plasma-assisted chemical-vapor-deposition self-supporting diamond films with different qualities, black, gray and white. Experimental results show a weak fiber texture and a large average grain size at the growth side, consistent with the model usually used to described chemical-vapor-deposition growth with a preferred orientation of the grains. Macroscopic residual stresses have been determined by means of x-ray measurements, through the “sin² ψ” method. Compressive and tensile stresses are reported at both faces of the samples. We show that stresses present at both growth face and nucleation face cannot be explained by the usual models involving the average grain size. For some samples, a closer analysis of the sin² ψ curves reveals a shift from the linear behavior. This effect comes from various stress states and/or lattice parameters between the grains belonging to the texture and the randomly oriented grains. © 1999 American Institute of Physics.