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-depositi on self-supporting diamond films with different qualities, black, gray and white. Experimental results show a weak fiber texture and a large average g rain size at the growth side, consistent with the model usually used to des cribed chemical-vapor-deposition growth with a preferred orientation of the grains. Macroscopic residual stresses have been determined by means of x-r ay measurements, through the "sin(2) psi" method. Compressive and tensile s tresses are reported at both faces of the samples. We show that stresses pr esent at both growth face and nucleation face cannot be explained by the us ual models involving the average grain size. For some samples, a closer ana lysis of the sin(2) psi curves reveals a shift from the linear behavior. Th is effect comes from various stress states and/or lattice parameters betwee n the grains belonging to the texture and the randomly oriented grains. (C) 1999 American Institute of Physics. [S0003-6951(99)04139-X].