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. An atomic layer deposition (ALD) process for forming a thin film on a substrate, the process comprising a plurality of deposition cycles each comprising:
contacting the substrate with a first vapor phase reactant; and
contacting the substrate with a second vapor phase reactant, wherein the second vapor phase reactant comprises P(AR 1 R 2 R 3 ) 3 , wherein R 1 , R 2 , and R 3 are alkyl groups with one or more carbon atoms and A is Si or Ge.
2. The process of claim 1 , wherein the second vapor phase reactant comprises P(SiMe 2 t Bu) 3 , P(SiET 3 ) 3 or P(SiMe 3 ) 3 .
3. The process of claim 2 , wherein the second vapor phase reactant comprises P(SiMe 3 ) 3 .
4. The process of claim 1 , wherein any one or more of R 1 , R 2 , and R 3 comprises a heteroatom selected from the group of N, O, F, Si, P, S, Cl, Br and I.
5. The process of claim 1 , wherein any one or more of R 1 , R 2 , and R 3 comprises a halogen atom.
6. The process of claim 1 , additionally comprising removing excess first reactant after contacting the substrate with the first vapor phase reactant and prior to contacting the substrate with the second vapor phase reactant.
7. The process of claim 1 , wherein the substrate is exposed to a purge gas after contacting the substrate with the first vapor phase reactant and prior to contacting the substrate with the second vapor phase reactant.
8. The process of claim 1 , wherein excess second vapor phase reactant is removed after contacting the substrate with the second vapor phase reactant.
9. The process of claim 1 , wherein the first vapor phase reactant is a vapor phase halide reactant.
10. The process of claim 1 , wherein the first vapor phase reactant does not comprise transition metal.
11. The process of claim 1 , wherein the thin film is a Group III-V compound semiconductor film.
12. The process of claim 1 , wherein the thin film comprises P-Te, P-Se, In-P, Ga-P, Cu-P, Al-P or combinations thereof.
13. The process of claim 1 , wherein the first vapor phase reactant is not alcohol, water, or ozone.
14. An atomic layer deposition (ALD) process for forming a P-containing thin film on a substrate, the process comprising a plurality of deposition cycles comprising in order:
contacting the substrate with a first vapor phase reactant;
removing excess first reactant;
contacting the substrate with a second vapor phase reactant, wherein the second vapor phase reactant comprises P[A 1 (X 1 R 1 R 2 R 3 ) 3 ][A 2 (X 2 R 4 R 5 R 6 ) 3][A 3 (X 3 R 7 R 8 R 9 ) 3 ], wherein A 1 , A 2 , A 3 can be independently selected to be Si or Ge and wherein R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , and R 9 , can be independently selected to be alkyl, hydrogen, alkenyl, alkynyl or aryl groups and X 1 , X 2 , and X 3 can be independently selected to be Si, Ge, N, or O; and
removing excess second reactant and reaction byproducts, if any, from the reaction chamber.
15. The process of claim 14 , wherein the first vapor phase reactant comprises Ga, Se, Te, Cu, In or Al.
16. The process of claim 14 , wherein the first vapor phase reactant comprises a halide reactant.
17. The process of claim 14 , wherein excess first reactant is removed by purging with an inert gas.
18. The process of claim 14 , wherein the P-containing thin film comprises P-Te, P-Se, In-P, Ga-P, Cu-P, Al-P or combinations thereof.
19. The method of claim 14 , wherein X 1 , X 2 and X 3 are Si.
20. The process of claim 19 , wherein the second vapor phase reactant comprises P[Si(SiR 1 R 2 R 3 ) 3 ][Si(SiR 4 R 5 R 6 ) 3 ][Si(SiR 7 R 8 R 9 ) 3 ].
21. The process of claim 14 , wherein X 1 , X 2 and X 3 are N and each N is bound to two of the R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , and R 9 groups.
22. The process of claim 21 , wherein the second vapor phase reactant comprises P[Si(NR 1 R 2 ) 3 ][Si(NR 3 R 4 ) 3 ][Si(NR 5 R 6 ) 3 ].
23. The process of claim 14 , wherein X 1 , X 2 and X 3 are O and each O is bound to one of the R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , and R 9 groups.
24. The process of claim 23 , wherein the second vapor phase reactant comprises P[Si(OR 1 ) 3 ][Si(OR 2 ) 3 ][Si(OR 3 ) 3 ].