Correlation between oxidation resistance and crystallinity of Ti-Al as a barrier layer for high-density memories.

Journal Article · Sat Jan 01 04:00:00 EST 2000 · Acta Materialia

DOI:https://doi.org/10.1016/S1359-6454(00)00148-8· OSTI ID:942971

Aggarwal, S; Nagaraj, B; Jenkins, I G; Li, H; Sharma, R P; Salamanca-Riba, L; Ramesh, R; Dhote, A M; Krauss, A R; Auciello, O

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 Al{sub 2}O{sub 3} induced by the segregation of Al to the LSCO/Ti-Al interface. For amorphous Ti-Al, XPS reveals that no Al{sub 2}O{sub 3} layer is formed. In addition, Rutherford backscattering analysis shows almost no difference in the Ti-peak spectrum before and after deposition of LSCO.

• Research Organization: Argonne National Laboratory (ANL)
• Sponsoring Organization: SC; NSF
• DOE Contract Number: AC02-06CH11357
• OSTI ID: 942971
• Report Number(s): ANL/MSD/JA-36339
• Journal Information: Acta Materialia, Journal Name: Acta Materialia Journal Issue: 2000 Vol. 48; ISSN 1359-6454; ISSN ACMAFD
• Country of Publication: United States
• Language: ENGLISH

Related Subjects

36 MATERIALS SCIENCE
BACKSCATTERING
CAPACITORS
CHEMICAL REACTIONS
CORRELATIONS
DEPOSITION
DIFFUSION BARRIERS
ELECTRICAL PROPERTIES
ELECTRODES
FERROELECTRIC MATERIALS
GEOMETRY
LAYERS
MATERIALS
METALLIC GLASSES
OXIDATION
SEGREGATION
SUBSTRATES
THIN FILMS
TITANIUM ALLOYS
TRANSMISSION ELECTRON MICROSCOPY
USES
X-RAY PHOTOELECTRON SPECTROSCOPY