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 halide reactant; and
contacting the substrate with a second vapor phase reactant, wherein the second vapor phase reactant comprises X(SiR 1 R 2 R 3 ) 3 , wherein R 1 , R 2 , and R 3 are alkyl groups with one or more carbon atoms and X is Sb or As.
2. The process of claim 1 , additionally comprising removing excess first reactant after contacting the substrate with the first vapor phase halide reactant and prior to contacting the substrate with the second vapor phase reactant.
3. The process of claim 1 , wherein the substrate is exposed to a purge gas after contacting the substrate with the first vapor phase halide reactant and prior to contacting the substrate with the second vapor phase reactant.
4. The process of claim 1 , wherein excess second vapor phase reactant is removed after contacting the substrate with the second vapor phase reactant.
5. The process of claim 1 , wherein the first vapor phase reactant does not comprise transition metal.
6. The process of claim 1 , wherein the thin film is a Group III-V compound semiconductor film.
7. The process of claim 1 , wherein the thin film comprises a ternary Group III-V compound.
8. The process of claim 7 , wherein the ternary Group III-V compound comprises one of (Ga, Al)As, (Ga, In)As or (Ga, In)(As, P).
9. The process of claim 1 , wherein the thin film comprises AlSb, GaSb or InSb or combinations thereof.
10. The process of claim 9 , wherein the thin film is a GaSb thin film.
11. The process of claim 1 , wherein the thin film comprises GaAs, InAs, AlAs or combinations thereof.
12. The process of claim 11 , wherein the thin film is a GaAs thin film.
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 an As-containing thin film on a substrate, the process comprising a plurality of As-deposition cycles comprising in order:
contacting the substrate with a first vapor phase halide reactant;
removing excess first reactant;
contacting the substrate with a second vapor phase reactant, wherein the second vapor phase reactant comprises As(SiR 1 R 2 R 3 ) 3 , and wherein R 1 , R 2 , and R 3 are alkyl groups with one or more carbon atoms; and
removing excess second reactant and reaction byproducts, if any, from the reaction chamber.
15. The method of claim 14 , wherein excess first reactant is removed by purging with an inert gas.
16. The method of claim 14 , wherein the first vapor phase reactant comprises Ga.
17. The method of claim 16 , wherein the As-containing film is GaAs.
18. An atomic layer deposition (ALD) process for forming a Sb-containing thin film on a substrate comprising a plurality of Sb deposition cycles comprising:
contacting the substrate with a first vapor phase halide reactant;
removing excess first reactant;
contacting the substrate with a second vapor phase reactant, wherein the second vapor phase reactant comprises Sb(GeR 1 R 2 R 3 ) 3 , wherein R 1 , R 2 , and R 3 are alkyl groups with one or more carbon atoms.
19. The method of claim 18 , wherein excess first reactant is removed by purging with an inert gas.
20. The method of claim 18 , wherein the first vapor phase reactant comprises gallium.
21. The method of claim 20 , wherein the Sb-containing thin film comprises GaSb.