TiSiN Films Research Articles

Metallorganic Chemical Vapor Deposited TiN Barrier Enhancement with SiH4 Treatment

Copper diffusion barrier performance of titanium nitride films was enhanced by formation of a ternary Ti-Si-N layer. The TiSiN films are prepared by chemical vapor deposition (CVD) using a metallorganic precursor (MOCVD-TiN) by thermal decomposition of tetrakis(dimethylamino)titanium (TDMAT). The deposition is followed by plasma treatment with a gas mixture of nitrogen and hydrogen in order to reduce the resistivity of the films. Finally, the films are in situ exposed to silane. This leads to the formation of a Si-N bond layer in the TiSiN film. The process delivers a film with conformal step coverage and low resistivity with improved barrier performance for advanced Cu metallization. The barrier performance as a function of the plasma treatment and/or the exposure is explained by the microstructural, compositional, and chemical changes in the films. © 2001 The Electrochemical Society. All rights reserved.

Physical Properties and Diffusion Characteristics of CVD-Grown TiSiN Films

AbstractTiSiN films grown by chemical vapor deposition were characterized to evaluate the properties relevant to the application as a diffusion barrier in Cu-based interconnects. The films were grown using TiI4 + SiI4 + NH3 + H2 chemistry at substrate temperature, 370°C, and SiI4 - to-TiI4 precursor flow rate ratio of 30. The combined results from x-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM) revealed that the bulk of Ti32Si21N42 films were predominantly consisted of a mixture of cubic TiN and amorphous SiNx phases. The specific electrical resistivity of the films was about 2000 μΩcm which is a few times higher than that of sputtered TiSiN films having similar composition and thicknesses. The 40 nm-thick barrier appeared to be thermally stable against Cu diffusion at the annealing temperatures up to 550°C. Breakdown of this diffusion barrier occurred at 600°C and was accompanied by the formation of Cu3Si protrusions at the TiSiN/Si interface.

Evaluation of LPCVD MeSiN (MeTa, Ti, W, Re) diffusion barriers for Cu metallizations

LPCVD MeSiN (MeRe, W, Ti, Ta) thin films were investigated for use as diffusion barriers between Cu overlayer and oxidized silicon substrates. Gaseous precursors were silane, in situ fabricated metal chloride, ammonia, hydrogen and argon. Thermodynamic simulations of the MeSiN and the CVD MeSiNClHAr systems were combined with the experimental study. It was shown that the existence (titanium and tantalum) or non-existence (rhenium and tungsten) of stable metal nitrides could explain the differences observed in the morphology of the four systems. Amorphous or nanocrystallized ReSiN and WSiN whereas crystallized TiSiN and TaSiN films were deposited. The ReSiN an WSiN layers crystallization temperature was found to be around 1173 K. Their morphology, thermal stability, resistivity and the performances of the four copper metallized MeSiN systems were evaluated. WSiN material appeared as the most promising diffusion barrier thanks to its morphology, resistivity around 1 mΩ cm and performances in blocking copper diffusion.