Synthesis and use of precursors for ald of group va element containing thin films

Abstract

Atomic layer deposition (ALD) processes for forming Group VA element containing thin films, such as Sb, Sb—Te, Ge—Sb and Ge—Sb—Te thin films are provided, along with related compositions and structures. Sb precursors of the formula Sb(SiR1R2R3)3 are preferably used, wherein R1, R2, and R3 are alkyl groups. As, Bi and P precursors are also described. Methods are also provided for synthesizing these Sb precursors. Methods are also provided for using the Sb thin films in phase change memory devices.

We claim: 
     
         1 . A method for making a precursor comprising Bi, the method comprising:
 forming a first product by reacting a Group IA metal with a compound comprising Bi; and   subsequently combining a second reactant comprising R 1 R 2 R 3 SiX with the first product, wherein R 1 , R 2  and R 3  are alkyl groups with one or more carbon atoms and X is a halogen atom, thereby forming the precursor comprising Bi, wherein the precursor has a formula Bi(SiR 1 R 2 R 3 ) 3 .   
     
     
         2 . The method of  claim 1 , wherein the Group IA metal is Na, Li or K. 
     
     
         3 . The method of  claim 1 , wherein the compound comprising Bi is elemental Bi. 
     
     
         4 . The method of  claim 1 , wherein the second reactant comprises Et 3 SiCl and the precursor with the formula Bi(SiEt 3 ) 3  is formed. 
     
     
         5 . The method of  claim 1 , wherein the second reactant comprises Me 3 SiCl and the precursor with the formula Bi(SiMe 3 ) 3  is formed. 
     
     
         6 . The method of  claim 1 , wherein R 1  and R 2  are methyl groups and R 3  is a tertbutyl group, and the precursor with the formula Bi(SiMe 2   t Bu) 3  is formed. 
     
     
         7 . The method of  claim 1 , wherein one or more of DME, THF, toluene, and xylene is used as a solvent in the reaction forming the first product. 
     
     
         8 . The method of  claim 1 , wherein a hydrocarbon is used as a solvent and naphthalene or ammonia is used as a catalyst in the reaction forming the first product. 
     
     
         9 . The method of  claim 1 , wherein R 1 , R 2  and R 3  are all the same group. 
     
     
         10 . The method of  claim 1 , wherein R 1 , R 2  and R 3  are all different groups. 
     
     
         11 . A method for making a precursor comprising Bi, the method comprising:
 forming a first product by reacting a Group IA metal with a compound comprising Bi; and   subsequently combining a second reactant having the formula R 1 R 2 R 3 AX with the first product, wherein R 1 , R 2  and R 3  are alkyl groups with one or more carbon atoms, A is Si, Sn, or Ge, and X is a halogen atom, thereby forming the precursor comprising Bi, wherein the precursor has a formula Bi(AR 1 R 2 R 3 ) 3 .   
     
     
         12 . The method of  claim 11 , wherein the Group IA metal is Na, Li or K. 
     
     
         13 . The method of  claim 11 , wherein the compound comprising Bi is elemental Bi. 
     
     
         14 . The method of  claim 11 , wherein the second reactant has the formula R 1 R 2 R 3 SiX. 
     
     
         15 . The method of  claim 11 , wherein the second reactant is Et 3 ACl and the precursor comprising Bi is Bi(AEt 3 ) 3 . 
     
     
         16 . The method of  claim 15 , wherein the second reactant is Et 3 SiCl and the precursor comprising Bi is Bi(SiEt 3 ) 3 . 
     
     
         17 . The method of  claim 11 , wherein the second reactant is Me 3 ACl and the precursor comprising Bi is Bi(AMe 3 ) 3 . 
     
     
         18 . The method of  claim 11 , wherein the second reactant is Me 2   1 ′BuAX and the precursor comprising Bi is Bi(AMe 2   1 ′Bu) 3 . 
     
     
         19 . The method of  claim 11 , wherein one or more of DME, THF, toluene, and xylene is used as a solvent in the reaction forming the first product. 
     
     
         20 . The method of  claim 11 , wherein a hydrocarbon is used as a solvent and naphthalene is used as a catalyst in the reaction forming the first product.