EFFECT OF BORON INCORPORATION ON THE LATTICE-PARAMETER AND TEXTURE OF DIAMOND FILMS DEPOSITED BY CHEMICAL-VAPOR-DEPOSITION ON SILICON

Incorporation of boron in polycrystalline diamond films deposited on Si is shown to decrease or increase the lattice parameter below and above about 10(19) B cm(-3), respectively. At lower values of doping, the lattice parameter is lower than that of the undoped films, while their [111] texture is maintained. At higher values, the lattice parameter increases rapidly above that of the undoped films, while the [111] texture is progressively lost until it becomes untextured at 6 x 10(20) B cm(-3). A coherent interpretation of these results is proposed, based on a decrease and an increase of the defect concentration with B incorporation below and above 10(19) B cm(-3), with the hypothesis that the defects increase the diamond lattice parameter.