Control of epitaxial orientation of TiN thin films grown by N-implantation

Nitrogen ions Nq2 . with 62 keV have been implanted into 100-nm thick films prepared by evaporation of Ti on thermally cleaned NaCl substrates held at room temperature RT.and 2508C. Unimplanted and N-implanted Ti films have been examined mainly by transmission electron microscopy. The evaporated films grown at RT consisted of 03P5.- and 21P0.-oriented hcp-Ti, and 110.-oriented CaF2-type TiH x . The N-implantation into the 03P5.-oriented hcp-Ti and 110.-oriented TiH , results in the epitaxial growth of the 001.- and 110.-oriented TiN , respectively, whereas nitriding of x y the 21P0.-oriented hcp-Ti gives rise to the growth of 110.-oriented TiN rotated by ;98 with respect to that grown from y the 110.-oriented TiH . On the other hand, the Ti films grown at 2508C consisted of only the 03P5.-oriented hcp-Ti. It has x been clearly shown that only the 001.-oriented TiN film is epitaxially grown by N-implantation into the as-grown y 03P5.-oriented hcp-Ti. The control of epitaxial orientation of the TiN films grown by N-implantation and nitriding y mechanism of epitaxial Ti thin films are discussed. q1998 Elsevier Science B.V. All rights reserved