Stabilization of thin tungsten films on silicon during rapid thermal annealing in nitrogen

Thesis/Dissertation · Mon Dec 31 23:00:00 EST 1990

OSTI ID:6907374

Smith, P M

Thin W films on Si, deposited by electron-beam evaporation or sputtering, are shown to be stabilized against silicidation by a N[sub 2] ambient during rapid thermal annealing to temperatures of 1100[degree]C. The behavior of the W films in contact with Si was monitored following anneals in Ar and N[sub 2] ambients. Tungsten films annealed in an Ar ambient reacted fully to form the stable silicide, WSi[sub 2], while films annealed in N[sub 2] remained elemental W. The stability of W films with incorporated N was studied further by subsequent annealing in an Ar ambient. Complete stabilization of the W films was only achieved for N doses above 2.0 [times] 10[sup 17] N atoms/cm[sub 2]. At lower doses, a continual supply of N was necessary to maintain the stabilization by consumption of mobile Si at the interface. In contrast to films deposited by e-beam evaporation or sputtering, films deposited by chemical vapor deposition (CVD) reacted to form WSi[sub 2], regardless of the annealing ambient, at a substantially faster rate than the other samples. AES measurements show this reaction is the result of an absence of measurable O in the CVD films.

• Research Organization: Cornell Univ., Ithaca, NY (United States)
• OSTI ID: 6907374
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360101* -- Metals & Alloys-- Preparation & Fabrication
ANNEALING
CHEMICAL COATING
CHEMICAL VAPOR DEPOSITION
COATINGS
DEPOSITION
ELEMENTS
ENERGY BEAM DEPOSITION
ENERGY BEAM DEPOSITION FILMS
FILMS
HEAT TREATMENTS
METALS
SEMIMETALS
SILICON
STABILIZATION
SURFACE COATING
THIN FILMS
TRANSITION ELEMENTS
TUNGSTEN