Tungsten disilicide

Structural formula
__ W     __ Si
General
Surname	Tungsten disilicide
other names	Tungsten silicide (ambiguous)
Molecular formula	WSi 2
Brief description	blue gray solid
External identifiers / databases
CAS number 12039-88-2 EC number 234-909-0 ECHA InfoCard 100,031,723 PubChem 16212546 Wikidata Q414364
properties
Molar mass	240.01 g mol −1
Physical state	firmly
density	9.3 g cm −3
Melting point	2160 ° C
solubility	almost insoluble in water
safety instructions
GHS labeling of hazardous substances no GHS pictograms H and P phrases H: no H-phrases P: no P-phrases
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Tungsten disilicide is an inorganic chemical compound of tungsten from the group of silicides . In addition to this, there is also the pentatungsten trisilicide W ₅ Si ₃ .

Extraction and presentation

Tungsten disilicide can be obtained by reacting monosilane , dichlorosilane or disilane with tungsten hexafluoride .

${\displaystyle \mathrm {2\ SiH_{4}+WF_{6}\longrightarrow WSi_{2}+6\ HF+H_{2}} }$

${\displaystyle \mathrm {2\ SiH_{2}Cl_{2}+WF_{6}+3\ H_{2}\longrightarrow WSi_{2}+6\ HF+2\ HCl} }$

${\displaystyle \mathrm {Si_{2}H_{6}+WF_{6}\longrightarrow WSi_{2}+6\ HF} }$

properties

Tungsten disilicide is a blue-gray solid that is insoluble in water. It has a tetragonal crystal structure of the calcium carbide or molybdenum disilicide type with the space group I 4 / mmm (space group no. 139) .

use

Tungsten disilicide is used as a contact material in microelectronics and is deposited using chemical vapor deposition (CVD).

Individual evidence

1. ↑ ^{a b c d e} W. M. Haynes (Ed.): CRC handbook of chemistry and physics. A ready-reference book of chemical and physical data . founded by David R. Lide. 93rd edition. CRC Press, Boca Raton 2012, ISBN 978-1-4398-8049-4 , pp. 4–96 (English, limited preview in Google Book Search).
2. ↑ ^{a b} Data sheet Tungsten silicide, −325 mesh, 99.5% from Sigma-Aldrich , accessed on October 12, 2012 ( PDF ).
3. ↑ External identifiers from or database links to Pentawolframtrisilicid : CAS number: 12039-95-1, EC number: 234-912-7, ECHA -InfoCard: 100031726 , PubChem : 6336893 , ChemSpider : 4891886 , Wikidata : Q82897389 .
4. ^ Hugh O. Pierson: Handbook of Chemical Vapor Deposition, 2nd Edition: Principles, Technology ... William Andrew, 1999, ISBN 0-8155-1743-2 , pp. 332 ( limited preview in Google Book search).
5. ^ Peter Paetzold: Chemistry: An introduction . Walter de Gruyter, 2010, ISBN 3-11-020268-9 , p. 199 ( limited preview in Google Book search).
6. ↑ Werner Martienssen, Hans Warlimont: Springer Handbook of Condensed Matter and Materials Data . Springer, 2005, ISBN 3-540-44376-2 , pp. 474 ( limited preview in Google Book search).
7. ↑ Horst Briehl: Chemistry of materials . Springer, 2007, ISBN 3-8351-0223-0 , pp. 255 ( limited preview in Google Book search).
8. ^ RA Levy: Microelectronic Materials and Processes . Springer, 1989, ISBN 0-7923-0154-4 , pp. 204, 237 f . ( limited preview in Google Book search).