TY - JOUR
KW - Electrodes
KW - Crystal structure
KW - Electric properties
KW - Ferroelectricity
KW - Ferroelectric devices
KW - Ferroelectric capacitors
KW - Interfaces (materials)
KW - Diffusion barrier
KW - X-ray photoelectron spectroscopy
KW - Chemical reactions
KW - Diffusion in solids
KW - Intermetallics
KW - Oxidation resistance
KW - Segregation (metallography)
KW - High density memories
KW - Titanium aluminum
KW - Titanium alloys
AU - S Aggarwal
AU - B Nagaraj
AU - I.G Jenkins
AU - H Li
AU - R.P Sharma
AU - L Salamanca-Riba
AU - Ramamoorthy Ramesh
AU - A.M Dhote
AU - A.R Krauss
AU - O Auciello
AB - 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.
BT - Acta Materialia
DO - 10.1016/S1359-6454(00)00148-8
LA - eng
M1 - 13
N1 - cited By 28
N2 - 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.
PY - 2000
SP - 3387
EP - 3394
T2 - Acta Materialia
TI - Correlation between oxidation resistance and crystallinity of Ti-Al as a barrier layer for high-density memories
VL - 48
SN - 13596454
ER -