@article{33778, keywords = {electrodes, crystal structure, electric properties, ferroelectricity, Ferroelectric devices, Ferroelectric capacitors, Interfaces (materials), Diffusion barrier, X ray photoelectron spectroscopy, Chemical reactions, Diffusion in solids, Intermetallics, Oxidation resistance, Segregation (metallography), High density memories, Titanium aluminum, Titanium alloys}, author = {S Aggarwal and B Nagaraj and I.G Jenkins and H Li and R.P Sharma and L Salamanca-Riba and Ramamoorthy Ramesh and A.M Dhote and A.R Krauss and O Auciello}, title = {Correlation between oxidation resistance and crystallinity of Ti-Al as a barrier layer for high-density memories}, abstract = {The Ti-Al intermetallic material system has been investigated for application as a conducting diffusion barrier in a three-dimensional stacked capacitor-transistor geometry. La-Sr-Co-O (LSCO)/Pb-Zr-Ti-Nb-O/La-Sr-Co-O ferroelectric capacitors were fabricated on Ti-Al/polycrystalline-Si/Si substrates. The electrical and ferroelectric properties are found to correlate strongly with the crystallinity of the Ti-Al layer. The crystalline Ti-Al layer shows a distinct chemical reaction with the bottom LSCO electrode thus preventing ohmic electrical contact between the ferroelectric capacitor and transistor. In contrast, the amorphous Ti-Al layer does not react and forms an ohmic contact to LSCO. For crystalline Ti-Al, X-ray photoelectron spectroscopy (XPS) shows the formation of Al2O3 induced by the segregation of Al to the LSCO/Ti-Al interface. For amorphous Ti-Al, XPS reveals that no Al2O3 layer is formed. In addition, Rutherford backscattering analysis shows almost no difference in the Ti-peak spectrum before and after deposition of LSCO.}, year = {2000}, journal = {Acta Materialia}, volume = {48}, number = {13}, pages = {3387-3394}, issn = {13596454}, doi = {10.1016/S1359-6454(00)00148-8}, note = {cited By 28}, language = {eng}, }