High-temperature stability of chemically vapor-deposited tungsten-silicon couples rapid thermal annealed in ammonia and argon

Journal Article · Thu Dec 15 00:00:00 EST 1988 · J. Appl. Phys.; (United States)

DOI:https://doi.org/10.1063/1.342003· OSTI ID:6947784

Broadbent, E K; Morgan, A E; Flanner, J M; Coulman, B; Sadana, D K; Burrow, B J; Ellwanger, R C

A rapid thermal anneal (RTA) in an NH/sub 3/ ambient has been found to increase the thermal stability of W films chemically vapor deposited (CVD) on Si. W films deposited onto single-crystal Si by low-pressure CVD were rapid thermal annealed at temperatures between 500 and 1100 /sup 0/C in NH/sub 3/ and Ar ambients. The reactions were studied using Rutherford backscattering spectrometry, x-ray diffraction, Auger electron spectroscopy, transmission electron microscopy, and four-point resistivity probe. High-temperature (greater than or equal to1000 /sup 0/C) RTA in Ar completely converted W into the low resistivity (31 ..mu cap omega.. cm) tetragonal WSi/sub 2/ phase. In contrast, after a prior 900 /sup 0/C RTA in NH/sub 3/, N inclusion within the W film and at the W/Si interface almost completely suppressed the W-Si reaction. Detailed examination, however, revealed some patches of WSi/sub 2/ formed at the interface accompanied by long tunnels extending into the substrate, and some crystalline precipitates in the substrate close to the interface. The associated interfacial contact resistance was only slightly altered by the 900 /sup 0/C NH/sub 3/ anneal. The NH/sub 3/-treated W film acted as a diffusion barrier in an Al/W/Si contact metallurgy up to at least 550 /sup 0/C, at which point some increase in contact resistance was measured.

• Research Organization: Philips Research Laboratories Sunnyvale, Signetics Company, Sunnyvale, California 94088-3409
• OSTI ID: 6947784
• Journal Information: J. Appl. Phys.; (United States), Vol. 64:12
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
SILICON
ELECTRIC CONTACTS
VAPOR DEPOSITED COATINGS
TUNGSTEN
CHEMICAL VAPOR DEPOSITION
STABILITY
TUNGSTEN SILICIDES
SYNTHESIS
ALUMINIUM
AMMONIA
ANNEALING
AUGER ELECTRON SPECTROSCOPY
BACKSCATTERING
CRYSTAL STRUCTURE
DIFFUSION
INTERFACES
THIN FILMS
TRANSMISSION ELECTRON MICROSCOPY
VERY HIGH TEMPERATURE
X-RAY DIFFRACTION
CHEMICAL COATING
COATINGS
COHERENT SCATTERING
DEPOSITION
DIFFRACTION
ELECTRICAL EQUIPMENT
ELECTRON MICROSCOPY
ELECTRON SPECTROSCOPY
ELEMENTS
EQUIPMENT
FILMS
HEAT TREATMENTS
HYDRIDES
HYDROGEN COMPOUNDS
METALS
MICROSCOPY
NITROGEN COMPOUNDS
NITROGEN HYDRIDES
REFRACTORY METAL COMPOUNDS
SCATTERING
SEMIMETALS
SILICIDES
SILICON COMPOUNDS
SPECTROSCOPY
SURFACE COATING
TRANSITION ELEMENT COMPOUNDS
TRANSITION ELEMENTS
TUNGSTEN COMPOUNDS
360101* - Metals & Alloys- Preparation & Fabrication
360104 - Metals & Alloys- Physical Properties