Effect of substrate surface on the structure and electronic properties of cubic boron nitride films

Abstract

Articles you may be interested inEffect of indium doping on physical properties of nanocrystallized SnS zinc blend thin films grown by chemical bath deposition J. Renewable Sustainable Energy 4, 011602 (2012); 10.1063/1.3676073 Physical properties of lanthanum monosulfide thin films grown on (100) silicon substrates Interdependence between stress, preferred orientation, and surface morphology of nanocrystalline TiN thin films deposited by dual ion beam sputtering J. Appl. Phys. 99, 113519 (2006); 10.1063/1.2197287 X-ray diffraction study of stress relaxation in cubic boron nitride films grown with simultaneous medium-energy ion bombardment Appl. Phys. Lett. 85, 5905 (2004); 10.1063/1.1836868Influence of substrate bias on practical adhesion, toughness, and roughness of reactive dc-sputtered zirconium nitride films Cubic boron nitride ͑c-BN͒ films were prepared by mass-selected ion beam deposition ͑MSIBD͒ technique. The effects of substrate surface roughness were investigated by boron and nitrogen k-edge x-ray absorption near-edge structure, x-ray diffraction, and atomic force microscopy. All the films are a mixture of nanocrystalline sp 3 -bonded c-BN and sp 2 -bonded BN phases. The substrate with a rough surface causes a decrease of the c-BN phase content of the film on it. A significant large lattice contraction of the c-BN crystallites in the films, relative to the bulk, is observed. It is also found that the electronic structure of the nanocrystalline c-BN films by MSIBD technique is somewhat different from that of microcrystalline c-BN / h-BN references. We attribute the effect of the nature of the substrate on the morphology and structure of the c-BN films to the orientation of sp 2 -bonded graphitic BN basal plane on the top surface of the films during their growth, and the lattice contraction and energy band structure modification of c-BN films to the large compressive stress, respectively.

X-ray Absorption Studies on the Growth Process of Radio-Frequency-Magnetron-Sputtered Boron Nitride Films: Effects of Bias Voltage and Substrate Temperature

“…This means that the basal plane of the sp 2 -BN structure tends to be perpendicular to the film surface (i.e., the c-axis is parallel to the surface). 15,16) This preferential orientation of the sp 2 -BN layer agrees with previous reports. 7,11) It is believed that a compressive internal stress in the growing film is necessary to nucleate c-BN and also leads to the preferential orientation of the h-BN (t-BN) layer.…”

Direct Deposition of Cubic Boron Nitride Films on Tungsten Carbide–Cobalt

“…Thus, the removal of Co using an acid solution triggers cBN formation. The roughening using the scratching and H 2 plasma treatments increases both the cBN fraction and the deposition rate, wholly opposed to the result for ion-beam deposition with 150 eV ions …”

“…The roughening using the scratching and H 2 plasma treatments increases both the cBN fraction and the deposition rate, wholly opposed to the result for ion-beam deposition with 150 eV ions. 22 The substrate bias current onto the scratched substrate measured in a pure He ICP as a function of V s is shown in Figure 4a. Pure He was used to avoid the effect of deposits, but the result well represents that for the He−N 2 −H 2 −BF 3 mixture.…”

“…18−20 For Si substrates, the cBN fraction increased with increasing initial surface roughness of the substrate, 21 wholly opposed to the result for ion-beam deposition with 150 eV ions. 22 This suggests that the nucleation energetics under such soft ion impact depends strongly on the apparent surface free energy of the substrate, i.e., the surface free energy per unit area multiplied by the actual surface area.…”

“…The threshold ion energy and deposition temperature were reduced to a few eV and 730 °C, respectively. The resulting film consisted of micrometer-sized grains with crystallographic morphology with the in-depth cBN fraction up to 70 vol %. − For Si substrates, the cBN fraction increased with increasing initial surface roughness of the substrate, wholly opposed to the result for ion-beam deposition with 150 eV ions . This suggests that the nucleation energetics under such soft ion impact depends strongly on the apparent surface free energy of the substrate, i.e., the surface free energy per unit area multiplied by the actual surface area.…”