Optimization of TiN thin film growth with in situ monitoring: the effect of bias voltage and nitrogen flow rate

TiN x thin films were deposited by d.c. reactive magnetron sputtering over a wide range of stoichiometry. The stoichiometry, structure and composition were monitored by in situ spectroscopic ellipsometry (SE). The effect of the substrate bias voltage (V b ) and nitrogen flow rate (Φ N ) on the above film properties was studied. Due to the bias voltage, nitrogen is extracted from the film surface and, for |V b |>120 V, substantial Ti resputtering takes place. By varying the nitrogen flow, Ti y N x phases stable at low percentages of nitrogen are deposited, while the transition to f.c.c. TiN x is always observed at Φ N =1.9 sccm. X-Ray diffraction was used to identify the phases. Finally, the results of the fitting and simulation of the SE measurements using the effective medium approximation are presented to demonstrate the suitability of SE for the in situ characterization of complex Ti y N x film structures offering special properties.

[1]  I. Alexandrou,et al.  In situ spectroscopic ellipsometry to monitor the process of TiNx thin films deposited by reactive sputtering , 1995 .

[2]  Sören Berg,et al.  Predicting thin‐film stoichiometry in reactive sputtering , 1988 .

[3]  A. Bengtson,et al.  Titanium nitride deposition on hardened high speed steel by reactive magnetron sputtering , 1990 .

[4]  D. Aspnes.  Optical properties of thin films , 1982 .

[5]  J. Sundgren,et al.  Structure and properties of TiN coatings , 1985 .

[6]  G. Lempérière,et al.  Influence of the nitrogen partial pressure on the properties of d.c.-sputtered titanium and titanium nitride films , 1984 .

[7]  I. Petrov,et al.  Polycrystalline TiN films deposited by reactive bias magnetron sputtering: Effects of ion bombardment on resputtering rates, film composition, and microstructure , 1992 .

[8]  W. Petuskey,et al.  Phase chemistry in the Ti-Si-N system: Thermochemical review with phase stability diagrams , 1994 .

[9]  J. Simmons,et al.  Low temperature radio frequency sputter deposition of TiN thin films using optical emission spectroscopy as process monitor , 1994 .

[10]  I. Alexandrou,et al.  Electron microscopy characterization of TiN films on Si, grown by d.c. reactive magnetron sputtering , 1995 .

[11]  K. Pourrezaei,et al.  Growth and properties of TiN and TiOxNy diffusion barriers in silicon on sapphire integrated circuits , 1987 .

[12]  I. Alexandrou,et al.  Schottky barrier contacts of titanium nitride on n-type silicon , 1995 .