Tantalum nitride and tungsten as diffusion barriers for palladium and cobalt silicides in multilayer metallization schemes
The efficiency of two thin-film diffusion barriers to be used in silicide/aluminum metallization schemes for silicon integrated circuits were evaluated. Control samples of Si/CoSi{sub 2}/Al and Si/Pd{sub 2}Si/Al, and test samples of Si/CoSi{sub 2}/Ta{sub 2}N/Al, Si/CoSi{sub 2}/W/Al and Si/Pd{sub 2}Si/Ta{sub 2}N/Al were used for sheet resistance, X-ray diffraction, Rutherford backscattering, and Auger-electron spectroscopic measurements. TEM studies were carried out on representative samples to examine the nature of the interfaces. Results from the analytical tests indicated that all three types of test samples are resistant to gross diffusion and intermixing of Co, Pd, Al and Si. They also showed that in the control samples, annealing causes interdiffusion of these species, necessitating the presence of a diffusion barrier. For test contacts, results demonstrated that although diffusion barriers may be successful in preventing metallurgical interdiffusion, they may not be viable in integrated circuit technology. Possible modifications were identified to eliminate the high contact resistance in the CoSi{sub 2} devices. It was determined that the Si/Pd{sub 2}Si/Ta{sub 2}N/Al devices perform excellently despite annealing, indicating that the scheme may be successfully applied in VLSI technology.
- Research Organization:
- Rutgers-the State Univ., New Brunswick, NJ (USA)
- OSTI ID:
- 7154817
- Resource Relation:
- Other Information: Thesis (Ph. D.)
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
36 MATERIALS SCIENCE
COBALT SILICIDES
DIFFUSION BARRIERS
EVALUATION
INTEGRATED CIRCUITS
FABRICATION
PALLADIUM SILICIDES
TANTALUM NITRIDES
TUNGSTEN
THIN FILMS
COBALT COMPOUNDS
ELECTRONIC CIRCUITS
ELEMENTS
FILMS
METALS
MICROELECTRONIC CIRCUITS
NITRIDES
NITROGEN COMPOUNDS
PALLADIUM COMPOUNDS
PNICTIDES
REFRACTORY METAL COMPOUNDS
SILICIDES
SILICON COMPOUNDS
TANTALUM COMPOUNDS
TRANSITION ELEMENT COMPOUNDS
TRANSITION ELEMENTS
426000* - Engineering- Components
Electron Devices & Circuits- (1990-)
360601 - Other Materials- Preparation & Manufacture