Initial growth and properties of atomic layer deposited TiN films studied by in situ spectroscopic ellipsometry

Spectroscopic ellipsometry was used to study the initial growth of thin TiN films that are deposited by plasma-assisted at. layer deposition (PA-ALD) in which the thickness is perfectly controlled by the no. of PA-ALD cycles. After every PA-ALD cycle, ellipsometry data was obtained in the energy range 0.75-5.0 eV making a detailed study of the initial nucleation and the evolution of the film parameters as a function of the thickness possible. Both the Drude-Lorentz oscillator parameterization as well as the direct numerical inversion method were used to ext. the film thickness and dielec. function from the ellipsometry data. From the Drude term, metallic properties of the TiN film, such as resistivity and mean free path, are calcd. and these properties vary with film thickness. A detailed study of the film nucleation on chem. and thermal oxide substrates showed that the difference in surface hydroxyl d. results in a different nucleation behavior. An immediate nucleation on chem. oxide and a distinct nucleation delay on the thermal oxides were obsd. [on SciFinder (R)