Use of an energetic ion beam on the surface during physical vapor deposition

The microstructural evolution of polycrystalline TiNx alloy films deposited by de reactive magnetron sputter deposition from a Ti target in mixed Ar/N -2 discharges is reported. It is found that the films are underdense and ex hibit a pronounced columnar morphology at low growth temperatures and in th e absence of ion bombardment, while the addition of low-energy (E-i less th an or equal to 200 eV) ion irradiation during deposition in Ar-N-2 plasmas results in film densification, defect incorporation and a more equiaxed gra in structure. Low-energy ion irradiation provides increased apparent adatom mobility and, hence, larger grain size. The redistribution of elements nea r the surface of alloys subjected to ion bombardment is studied. The kineti cs of surface composition and the distribution profiles of elements in the subsurface layer are analyzed during the transition time between two steady -state regimes of sputtering after changes in the irradiation conditions. G ood agreement between the experimental and calculated results is obtained ( C) 2000 Elsevier Science B.V. All rights reserved.