Ultrahigh vacuum scanning tunneling microscopy (STM) is used to characterize the surface morphology of TiN(001) epitaxial layers grown by dc reactive magnetron sputtering at growth temperatures of Ts=650 and Ts=750°C. An auxiliary anode is used to bias the N2 plasma and produce a large flux of low-energy N2+ ions that bombard the film surface during growth: the ratio of the N2+ flux to the Ti growth flux is ≈25. At ion energies Ei near the threshold for the production of bulk defects (Ei=43 eV and Ts=650°C), ion bombardment decreases the amplitude of the roughness, decreases the average distance between growth mounds, and reduces the sharpness of grooves between growth mounds. The critical island radius for second layer nucleation Rc is approximately 12 and 17 nm at growth temperatures of 650 and 750°C respectively; at 650°C, Rc is reduced to ≈10 nm by ion bombardment.
|Original language||English (US)|
|Number of pages||7|
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|State||Published - 2000|
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics