Synthesis and use of precursors for ALD of group VA element containing thin films
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(SiR 1 R 2 R 3 ) 3 are preferably used, wherein R 1 , R 2 , and R 3 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.
1. A method for making a precursor comprising a group VA element, the method comprising:
forming a first product by reacting a Group IA metal with a compound comprising a group VA element, wherein the VA element is As; 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 a compound with the formula L(SiR 1 R 2 R 3 ) 3 , wherein L is the group VA element.
2. The method of claim 1 , wherein the Group IA metal is Na, Li or K.
3. The method of claim 1 , wherein the second reactant comprises Et 3 SiCl and L(SiEt 3 ) 3 is formed.
4. The method of claim 1 , wherein the second reactant comprises Me 3 SiCl and L(SiMe 3 ) 3 is formed.
5. The method of claim 1 , wherein one or more of the group of DME, THF, toluene, and xylene is used as a solvent in the reaction forming the first product.
6. 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.
7. The method of claim 1 , wherein R 1 , R 2 , and R 3 are all the same group.
8. The method of claim 1 , wherein R 1 , R 2 and R 3 are all different groups.
9. A method for making a precursor comprising a group VA element, comprising:
forming a first product by reacting a Group IA metal with a compound comprising a group VA element, wherein the VA element is As; and
subsequently combining a second reactant comprising 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 group VA element containing compound with the formula L(AR 1 R 2 R 3 ) 3 , wherein L is the group VA element, wherein the group VA element is As.
10. The method of claim 9 , wherein the second reactant comprises Et 3 ACl and L(AEt 3 ) 3 is formed.
11. The method of claim 9 , wherein the second reactant comprises Me 3 ACl and L(AMe 3 ) 3 is formed.
12. The method of claim 9 , wherein one or more of the group of DME, THF, toluene, and xylene is used as a solvent in the reaction forming the first product.
13. The method of claim 9 , wherein a hydrocarbon is used as a solvent and naphthalene is used as a catalyst in the reaction forming the first product.