Effect of intrinsic stress on preferred orientation in AlN thin films

Abstract

Articles you may be interested inSynthesis and characterization of 10nm thick piezoelectric AlN films with high c-axis orientation for miniaturized nanoelectromechanical devices Appl. Phys. Lett. Epitaxial growth and orientation of AlN thin films on Si(001) substrates deposited by reactive magnetron sputteringWe examine the effect of ion impact energy on the intrinsic stress and microstructure of aluminum nitride thin films deposited using a filtered cathodic arc. The dependence of intrinsic stress on ion impact energy is studied over the range from 0 to 350 V using dc bias and up to several kV for a fraction of the ions using pulse bias. For dc bias, the stress reaches a maximum at 200 V and decreases with further increase in ion bias. The preferred orientation of the crystallites was studied by cross-section transmission electron microscopy and diffraction. We found that there is a preference for the c crystallographic axis to lie in the plane of the film under high intrinsic stress conditions ͑4 GPa͒, whereas a c-axis orientation perpendicular to the plane of the film was observed for low intrinsic stress ͑0.25 GPa͒. We carried out calculations of the expected distribution of intensity in cross-sectional electron diffraction patterns to predict the effect of rotation freedom of crystallites with the c axis pinned. The calculated patterns agreed well with experiment.

Structure, mechanical and tribological properties of HfCx films deposited by reactive magnetron sputtering

“…demonstrated that TiC/a:C coatings prepared using a pulsed closed field unbalanced magnetron sputtering system showed high hardness (24)(25)(26)(27)(28)(29), low COF (0.24-0.25) and low wear rate (less than 2.5×10 −7 mm 3 /Nm) when the C concentration is in the range of 55-66 at.%. And Wilhelmsson et al [14] put forward a new design of low-friction nanocomposite carbide film succeeded in decreasing COF…”

Crystallographic texture in pulsed laser deposited hydroxyapatite bioceramic coatings

“…This, coupled with the anisotropic elastic modulus of the HA crystals, may result in textured polycrystalline configurations that minimize strain energy. Texture formation has been observed in other hexagonal ceramics deposited under anisotropic stress conditions and may be one of the main routes for strain energy relaxation [39]. Since our HA coatings exhibit no residual stress after deposition, as indicated by no detectable changes in peak position and width in XRD scans, it is essential to estimate the magnitude of stresses that may have been present during deposition.…”

Practical Plasma Immersion Ion Implantation for Stress Regulation and Treatment of Insulators

“…Changes in the preferred orientation of crystallites correlated with the relief of stress were also more recently observed for aluminium nitride (AlN) films deposited using a cathodic arc with PIII [13]. The highest stress obtained was around 4 GPa using a DC bias of 200 V with no PIII pulsed bias applied.…”