Tungsten disilicide

Chembox new
Name = Tungsten(IV) silicide
ImageFile =
ImageName = Tungsten disilicide
OtherNames =
Section1 = Chembox Identifiers
CASNo = 12039-88-2
Section2 = Chembox Properties
Formula = WSi₂
MolarMass = 240.02 g/mol
Appearance = blue odorless powder
Density = 9.4 g/cm³, solid
Solubility = insoluble
MeltingPt = 2437 K (2164 °C)
BoilingPt =
Section7 = Chembox Hazards
EUClass = not listed
NFPA-H = 1
NFPA-R = 0
NFPA-F = 0

Tungsten disilicide, or just tungsten silicide (WSi₂) is an inorganic compound, a silicide of tungsten. It is an electrically conductive ceramic material.

It is used in microelectronics as a contact material, with resistivity 60-80 μΩ-cm; it forms at 1000 °C. It is often used as a shunt over polysilicon lines to increase their conductivity and increase signal speed. Tungsten silicide layers can be prepared by chemical vapor deposition, eg. using monosilane or dichlorosilane with tungsten hexafluoride as source gases. The deposited film is non-stoichiometric, and requires annealing to convert to more conductive stoichiometric form. Tungsten silicide is a replacement for earlier tungsten films. [http://www.genus.com/cvd/cvd_materials.html] Tungsten silicide is also used as a barrier layer between silicon and other metals, e.g. tungsten.

Tungsten silicide also finds use in microelectromechanical systems and for oxidation-resistant coatings.

Films of tungsten silicide can be plasma-etched using eg. nitrogen trifluoride gas.

Tungsten nitride is another material with similar uses.

Tungsten silicide can react violently with substances such as strong acids, fluorine, oxidizers, and interhalogens.

References