METAL CHALCOGENIDE AQUEOUS PRECURSORS AND PROCESSES TO FORM METAL CHALCOGENIDE FILMS

• US 20110206599A1
• Filed: 02/22/2010
• Published: 08/25/2011
• Est. Priority Date: 02/22/2010
• Status: Active Grant

• Current Assignee: Inpria Corporation
• Original Assignee: Inpria Corporation
• Inventors: Clark, Benjamin L,, Keszler, Douglas A.
• Granted Patent: US 8,366,967 B2
• Time in Patent Office: Days
• US Class Current: 423/508
• CPC Class Codes: C09D 1/00 Coating compositions, e.g. paints, varnishes or lacquers, based on inorganic substances
• CPC Class Codes: C23C 18/1204 inorganic material, e.g. non-oxide and non-metallic such as sulfides, nitrides based compounds
• CPC Class Codes: C23C 18/1225 Deposition of multilayers of inorganic material

Abstract

Metal chalocogenide precursor solutions are described that comprise an aqueous solvent, dissolved metal formate salts and a chalcogenide source composition. The chalcogenide source compositions can be organic compounds lacking a carbon-carbon bond. The precursors are designed to form a desired metal chalcogenide upon thermal processing into films with very low levels of contamination. Potentially contaminating elements in the precursors form gaseous or vapor by-products that escape from the vicinity of the product metal chalcogenide films.

Claims

1. A metal chalcogenide precursor solution comprising an aqueous solvent having dissolved a metal cation, formate anions, and a chalcogenide composition selected from the group consisting of thiourea, thioformamide, selenourea, selenoformamide and a combination of thereof.

2. The metal chalcogenide precursor solution of claim 1 wherein the solution comprises a d-block metal cation and a p-block metal cation.

3. The metal chalcogenide precursor solution of claim 2 wherein the d-block metal cation comprises copper.

4. The metal chalcogenide precursor solution of claim 2 wherein the p-block cation comprise aluminum, gallium, indium or a combination thereof.

5. The metal chalcogenide precursor solution of claim 1 wherein the solvent comprises formic acid.

6. The metal chalcogenide precursor solution of claim 1 wherein the solvent comprises water and an alcohol.

7. The metal chalcogenide precursor solution of claim 1 wherein the chalcogenide composition comprises thiourea.

8. The metal chalcogenide precursor solution of claim 1 wherein the chalcogenide composition comprises selenourea.

9. The metal chalcogenide precursor solution of claim 1 wherein the concentration of chalcogenide composition is from about 0.03 molar to about 15.0 molar.

10. The metal chalcogenide precursor solution of claim 1 wherein the total cation concentration is from about 0.01 molar to about 3.0 molar.

11. A method for the formation of a precursor layer, the method comprising depositing the metal chalcogenide precursor solution of claim 1 onto a substrate surface.

12. The method of claim 11 further comprising removing at least a portion of the solvent of the deposited precursor solution.

13. The method of claim 12 further comprising depositing a second amount of precursor solution after removing at least a portion of the solvent of the initially deposited precursor solution.

14. The method of claim 11 wherein the depositing step is performed with a printing process.

15. A method for preparing an aqueous precursor of a metal chalcogenide, the method comprising forming an aqueous solution comprising a metal cation, formate anions, and a chalcogenide composition selected from the group consisting of thiourea, thioformamide, selenourea, selenoformamide or a combination of thereof.

16. The method of claim 15 wherein the aqueous solution comprises a d-block metal cation and a p-block metal cation.

17. The method of claim 15 wherein the forming of the aqueous solution comprises adding metal formate salts to an aqueous solution of the chalcogenide composition.

18. The method of claim 15 further comprising adjusting the concentration of aqueous precursor solution by providing for the evaporation of a selected amount of solvent to achieve a desired concentration.

19. A method for the formation of a metal chalcogenide film, the method comprising annealing a precursor layer at a temperature from about 50°

C. to about 750°

C. wherein the precursor layer comprises a metal cation, formate anions, and a chalcogenide composition selected from the group consisting of thiourea, thioformamide, selenourea, selenoformamide or a combination of thereof.

20. The method of claim 19 wherein the precursor layer comprises a d-block metal cation and a p-block metal cation.

21. The method of claim 19 wherein the annealing is performed using rapid thermal annealing.

22. The method of claim 19 wherein the annealing is performed in a furnace.

23. The method of claim 19 wherein the precursor layer comprises no more than about 5 weight percent solvent at the initiation of the annealing step.

24. The method of claim 19 wherein the precursor layer has a thickness from about 5 nm to about 10 microns.