An investigation was made of the effect of the microstructure of TiN films on the diffusion behavior of Cu. Cu/TiN films were synthesized on Si(100) substrate by the pulsed laser deposition technique. Three different microstructures of TiN were achieved by growing the films at different substrate temperatures, where higher deposition temperatures (~650C) led to epitaxial growth by the mechanism of domain matching epitaxy and lower temperature depositions resulted in polycrystalline and nanocrystalline TiN films. These structures were characterized by using X-ray diffraction and high-resolution transmission electron microscopy. The Cu was deposited in situ onto samples, with 3 different microstructures of TiN films on Si(100), by pulsed laser deposition. All 3 samples were simultaneously annealed (500C, 0.5h) under high vacuum in order to study the effect of the diffusion characteristics of Cu as a function of the microstructure of the TiN film. Secondary ion mass spectroscopy, Z-contrast imaging and electron energy-loss spectroscopy were used to understand the diffusion mechanisms and rationalize results in different microstructures.

Effect of Microstructure on Diffusion of Copper in TiN Films. A.Gupta, H.Wang, A.Kvit, G.Duscher, J.Narayan: Journal of Applied Physics, 2003, 93[9], 5210-4