Chemical vapor deposition method of producing fluorine-doped tin oxide coatings

• US 4,696,837 A
• Filed: 11/12/1985
• Issued: 09/29/1987
• Est. Priority Date: 06/25/1985
• Status: Expired due to Term

• Current Assignee: Arkema Incorporated (Arkema)
• Original Assignee: M&T Chemicals Incorporated
• Inventors: Lindner, Goerg H.
• Primary Examiner(s): Childs, Sadie L.
• Application Number:
  US06/797,364
• Time in Patent Office: 686 Days
• Field of Search: 427/109, 427/160, 427/166, 427/126.3, 427/85, 427/162, 427/255, 427/255.3, 65/60.52, 65/60.51, 65/60.5
• US Class Current: 427/255.35
• CPC Class Codes: C03C 17/2453 Coating containing SnO2
• CPC Class Codes: C23C 16/407 of zinc, germanium, cadmium, indium, tin, thallium or bismuth

Abstract

In accordance with the invention, there is provided herein an improved chemical vapor deposition method for forming fluorine-doped tin oxide coatings using a liquid coating composition which includes a reactive organic fluorine dopant and an organotin compound. The method is carried out under a defined set of process conditions such that the coating produced has a minimum and constant sheet resistance which is substantially independent of deposition temperature.

Claims

1. An improved chemical vapor deposition method of producing a fluorine-doped tin oxide coating which has a minimum and constant sheet resistance under different process conditions, comprising:

(a) forming a liquid coating composition comprising;

(1) an organic fluorine dopant wherein at least one fluorine atom is located alpha or beta to a functional group wherein carbon is bonded to oxygen selected from carboxylic acid, anhydride, ester, alcohol, ketone, acid halide, or ether; and

(2) an organotin compound, which is an alkyltin trichloride, a dialkyltin dichloride an alkyldichlorotin acetate, a dialkylchlorotin diacetate, or an ester tin trichloride;

or tin tetrachloride;

(b) vaporizing said liquid coating composition into a wet carrier gas to form a vapor mixture of carrier gas, water, organic fluorine dopant and said organotin compound or said tin tetrachloride; and

(c) decomposing said vapor mixture on a substrate to form said coating, characterized in that;

the vapor concentrations of said components are such that a parameter M, defined as;

##EQU2## where (AIR) is the concentration of the carrier gas, in moles 1 hr,

(H₂ O) is the concentration of water in the carrier gas, in moles 1 hr,

(OFD) is the concentration of organic fluorine dopant in the carrier gas, in moles 1 hr, and

(O) is the concentration of organotin compound in the carrier gas, in moles 1 hr,

has a value of less than 50,000, thereby to produce a fluorine-doped tin oxide coating having a minimum and constant sheet resistance for said values of M.

2. A process according to claim 1 wherein M has a value of 20,000 or less.

3. A process according to claim 1 in which the sheet resistance is about 25 ohms/sq. at a thickness of about 180-210 nm.

4. A process according to claim 1 in which the liquid coating composition comprises 2-10 wt. % of said organic fluorine dopant, and 90-98% of said organotin compound.

5. A process according to claim 1 wherein said liquid coating composition includes 1-10 wt. % of a polar organic compound.

6. A process according to claim 5 wherein said composition includes 2-10 wt. % of said organic fluorine dopant, 80-97 wt. % of said organotin compound, and 1-10 wt. % of said polar organic compound.

7. A process according to claim 6 wherein said polar organic compound is acetic anhydride, ethyl acetate or methylisobutylketone.

8. A process according to claim 1 wherein said vaporization temperature is 100°

-400°

C.

9. A process according to claim 1 wherein said deposition temperature is above 400°

and below 700°

C.

10. A process according to claim 1 wherein said substrate is glass.

11. The product of the process of claim 1 having a substantially minimum and constant sheet resistance with increasing deposition temperature.

12. A process according to claim 1 wherein said function group is a carboxylic acid.

13. A process according to claim 1 wherein said functional group is an anhydride.

14. A process according to claim 1 wherein said functional group is an ester.

15. A process according to claim 1 wherein said functional group is an alcohol.

16. A process according to claim 1 wherein said functional group is a ketone.

17. A process according to claim 1 wherein said functional group is an acid halide.

18. A process according to claim 1 wherein said functional compound is an alkyltin trichloride.

19. A process according to claim 1 wherein said organotin compound is a dialkyltin dichloride.

20. A process according to claim 1 wherein said organotin compound is an alkylchlorotin diacetate.

21. A process according to claim 1 wherein said organotin compound is an ester tin trichloride.

22. A process according to claim 1 wherein said liquid coating composition comprises:

(a) 1-30 wt. % of a reactive organic fluorine dopant compound which is trifluoroacetic acid, trifluoroacetic anhydride, ethyl trifluoroacetoacetate, trifluoroethanol, ethyl trifluoroacetate, pentafluoropropionic acid, 2-chloro-1,1,2-trifluoroethyl methyl ether, or 1,1,1-trifluoroacetylacetone; and

(b) 70-99 wt. % of an organotin compound which is an alkyltin trichloride, a dialkyltin dichloride, an alkyldichlorotin acetate, an alkylchlorotin diacetate, an ester tin trichloride;

or tin tetrachloride.

23. A process according to claim 22 wherein said organotin compound is monobutyltin trichloride, methyltin trichloride, isobutyltin trichloride, dibutyltin dichloride, di-t-butyltin dichloride, butyldichlorotin acetate, butylchlorotin diacetate, or carbethoxyethyltin trichloride.

24. A process according to claim 1 in which said fluorine dopant is 2-10 wt. % and said organotin compound is 90-98 wt. % of the composition.

25. A process according to claim 1 in which said fluorine dopant is about 5 wt. % and said organotin compound is about 95 wt. % of the composition.

26. A process according to claim 22 in which said fluorine dopant is trifluoroacetic acid.

27. A process according to claim 22 in which said fluorine dopant is trifluoroacetic anhydride.

28. A process according to claim 22 in which said fluorine dopant is ethyl trifluoroacetoacetate.

29. A process according to claim 22 in which said fluorine dopant is trifluoroethanol.

30. A process according to claim 22 in which said fluorine dopant is ethyl trifluoroacetate.

31. A process according to claim 22 in which said fluorine dopant is pentafluoropropionic acid.

32. A process according to claim 22 in which said fluorine dopant is 2-chloro-1,1,2-trifluoroethyl methyl ether.

33. A process according to claim 22 in which said fluorine dopant is 1,1,1-trifluoroacetylacetone.

34. A process according to claim 23 in which said organotin compound is monobutyltin trichloride.

35. A process according to claim 23 in which said organotin compound is methyltin trichloride.

36. A process according to claim 23 in which said organotin compound is isobutyltin trichloride.

37. A process according to claim 23 in which said organotin compound is dibutyltin dichloride.

38. A process according to claim 23 in which said organotin compound is di-t-butyltin dichloride.

39. A process according to claim 23 in which said organotin compound is butyldichlorotin acetate.

40. A process according to claim 15 in which said organotin compound is butylchlorotin diacetate.

41. A process according to claim 23 in which said organotin compound is carbethoxyethyltin trichloride.

42. A process according to claim 23 in which said fluorine dopant is trifluoroacetic acid, and said organotin compound is monobutyltin trichloride.

43. A process according to claim 23 comprising 2-10 wt. % of said organic fluorine dopant and 90-98 wt. % of said organotin compound.

44. A process according to claim 43 in which said fluorine dopant is trifluoroacetic acid and said organotin compound is monobutyltin trichloride.

45. A process according to claim 43 in which said fluorine dopant is trifluoroacetic and said organotin compound is butyldichlorotin acetate.

46. A process according to claim 43 in which said fluorine dopant is ethyl trifluoroacetoacetate and said organotin compound is monobutyltin trichloride.

47. A process according to claim 43 in which said fluorine dopant is trifluoroacetic acid and said organotin compound is diisobutyltin dichloride.

48. A process according to claim 43 in which said fluorine dopant is ethyl trifluoroacetate and said organotin compound is monobutyltin trichloride.

49. A process according to claim 43 in which said fluorine dopant is pentofluoropropionic acid and said organotin compound is monobutyltin trichloride.

50. A process according to claim 43 in which said fluorine dopant is trifluoroethanol and said organotin compound is monobutyltin trichloride.

51. A process according to claim 43 in which said fluorine dopant is 2-chloro-1,1,2-trifluoroethyl methyl ether and said organotin compound is monobutyltin trichloride.

52. A process according to claim 43 in which said fluorine dopant is 1,1,1-trifluoroacetyl acetone and said organotin compound is monobutyltin trichloride.

53. A process according to claim 1 which also includes 1-10 wt. % of a polar organic compound.

54. A process according to claim 53 in which said fluorine dopant is 2-10 wt. %, said organotin compound is 80-97 wt. %, and said polar organic compound is 1-10 wt. %, of said composition.

55. A process according to claim 54 comprising 2-10 wt. % of trifluoroacetic acid, 80-97 wt. % of monobutyltin trichloride and 1-10 wt. % of a polar organic liquid.

56. A process according to claim 54 in which the polar organic compound is methylisobutyl ketone, acetic anhydride or ethyl acetate.

57. A process according to claim 1 for making high quality fluorine-doped tin oxide coatings having a low sheet resistance and high visible light transmission in which said composition comprises:

(a) 1-30 wt. % of a reactive organic fluorine dopant compound where at least one fluorine atom is located alpha or beta to a functional group wherein carbon is bonded to oxygen selected from carboxylic acid, anhydride, ester, alcohol, ketone, acid halide, or ether and

(b) 70-99 wt. % of tin tetrachloride.

58. A process according to claim 57 in which said composition comprises:

(a) 1-30 Wt. % of an organic fluorine dopant compound which is trifluoroacetic acid, trifluoroacetic anhydride, ethyl trifluoroacetoacetate, trifluoroethanol, ethyl trifluoroacetate, pentafluoropropionic acid, 2-chloro-1,1,2-trifluoroethyl methyl ether, or 1,1,1-trifluoroacetylacetone; and

(b) 70-99 wt. % of tin tetrachloride.

59. A process according to claim 57 in which said fluorine dopant is 2-10 wt. %, and said tin tetrachloride is 90-98 wt. % of the composition.

60. A process according to claim 57 in which said fluorine dopant is about 5 wt. %, and said tin tetrachloride is about 95 wt. % of the composition.

61. A process according to claim 60 in which said fluorine dopant is trifluoroacetic acid.

62. A process according to claim 1 wherein said organic fluorine dopant is present in an amount of 1-30 wt. % of said composition, and said organotin compound is present in an amount of 70-99 wt. % of said composition.