Heterogeneous wet synthesis process for preparation of high purity tungsten pentahalide

Abstract

Synthesis of tungsten pentahalide compositions having low impurity profiles are disclosed. The specific impurity profile permits deposition of high purity tungsten-containing films using vapor deposition processes or other semiconductor manufacturing processes without introduction of performance-impacting contaminants.

What is claimed is: 
     
         1 . A method of synthesizing a WX 5 -containing composition, wherein X is Cl or Br, the method comprising reacting approximately 1 molar equivalent of a tungsten hexahalide with approximately 0.4 to approximately 0.6 molar equivalents of a disilane in a water reactive solvent to form a reaction mixture containing tungsten pentahalide and a halosilane by-product. 
     
     
         2 . The method of  claim 1 , wherein the tungsten pentahalide is WCl 5 . 
     
     
         3 . The method of  claim 1 , wherein the disilane has the formula Si 2 R 6 , with each R independently being H, a C1-C4 hydrocarbyl group, or a halide. 
     
     
         4 . The method of  claim 3 , wherein the disilane is Si 2 Me 6 . 
     
     
         5 . The method of  claim 1 , further comprising adding the tungsten hexahalide to the water reactive solvent, wherein the water reactive solvent comprises the halosilane by-product, to form a suspension prior to the reacting step. 
     
     
         6 . The method of  claim 5 , wherein the reacting step occurs when the disilane is added to the suspension. 
     
     
         7 . The method of  claim 1 , further comprising isolating the tungsten pentahalide from the reaction mixture by evaporating the halosilane by-product to produce an isolated WX 5 -containing composition. 
     
     
         8 . The method of  claim 7 , wherein the isolated WX 5 -containing composition comprises between approximately 95% w/w WCl 5  and approximately 100% WCl 5 . 
     
     
         9 . The method of  claim 7 , further comprising sublimating the isolated WX 5 -containing composition to produce the WX 5 -containing composition. 
     
     
         10 . The method of  claim 9 , wherein the WX 5 -containing composition comprising between approximately 0% to approximately 0.00002% by weight (0-200 ppb) of each of Al, Ti, V, Cr, Fe, Ni, Cu, and Mo. 
     
     
         11 . The method of  claim 1 , further comprising isolating the tungsten pentahalide from the reaction mixture by filtration to produce an isolated WX 5 -containing composition. 
     
     
         12 . The method of  claim 11 , wherein the isolated WX 5 -containing composition comprises between approximately 95% w/w WCl 5  and approximately 100% WCl 5 . 
     
     
         13 . The method of  claim 11 , further comprising sublimating the isolated WX 5 -containing composition to produce the WX 5 -containing composition. 
     
     
         14 . The method of  claim 13 , wherein the WX 5 -containing composition comprising between approximately 0% to approximately 0.00002% by weight (0-200 ppb) of each of Al, Ti, V, Cr, Fe, Ni, Cu, and Mo.