Coating, composed of an optically effective layer system, for substrates, whereby the layer system has a high anti-reflective effect, and method for the manufacturing of the coating

• US 5,216,542 A
• Filed: 10/19/1990
• Issued: 06/01/1993
• Est. Priority Date: 12/19/1989
• Status: Expired due to Fees

• Current Assignee: Balzers und Leybold Deutschland Holding AG (Balzers & Leybold Group)
• Original Assignee: Leybold Aktiengesellschaft
• Inventors: Roegels, Stephan, Hartig, Klaus, Zmelty, Anton, Szczyrbowski, Joachim
• Primary Examiner(s): Arnold, Bruce Y.
• Assistant Examiner(s): Phan, James
• Application Number:
  US07/599,988
• Time in Patent Office: 956 Days
• Field of Search: 359/580, 359/582, 359/585, 359/586, 359/587, 359/588, 359/590, 359/581, 427/166
• US Class Current: 359/588
• CPC Class Codes: C03C 17/3423 at least one of the coatings comprising a suboxide
• CPC Class Codes: C03C 17/3435 comprising a nitride, oxynitride, boronitride or carbonitride
• CPC Class Codes: C03C 17/3452 comprising a fluoride
• CPC Class Codes: C03C 2217/73 Anti-reflective coatings with specific characteristics
• CPC Class Codes: G02B 1/10 Optical coatings produced by application to, or surface treatment of, optical elements G02B1/08 takes precedence
• CPC Class Codes: G02B 1/115 Multilayers

Abstract

A coating, composed of an optically effective layer system for substrates, whereby the layer system has a high antireflective effect. On a front side of the substrate, facing the observer, in sequence from the front side to the observer, a first layer is arranged on the substrate, functioning as dielectric and comprising metal oxide. Thereupon follows a second layer comprising nitride, preferably TiN_x (x is equal to or greater than 1, preferably x=1.05). A third layer follows functioning as dielectric and comprising metal oxide. Thereupon a fourth layer follows comprising nitride, preferably TiN_x (x is equal to or greater than 1, preferably x=1.05). A fifth layer follows functioning as dielectric comprising metal oxide. On a backside of the substrate a TiN_x -layer (x≧1, preferably x=1.05) is arranged. The adequate selection of certain materials for the individual layers, of certain layer thicknesses and of a certain sequence of the individual layers results in a surprisingly good antireflective coating, contrast increase and antistatic effect. These good optical features of the layer system are reached with a small number of layers and with thin layer thicknesses. This, in turn, leads to an extremely cost saving manufacturing of the coating.

Claims

1. An anti-reflective layer system for substrates comprising:

a first layer arranged on the substrate on a side of the substrate toward an observer, functioning as a dielectric and comprising metal oxide;

a second layer arranged on said first layer, comprising nitride;

a third layer arranged on said second layer, functioning as a dielectric and comprising metal oxide;

a fourth layer arranged on said third layer, comprising nitride;

and a fifth layer arranged on said fourth layer, functioning as a dielectric and comprising metal oxide;

wherein said second layer comprises nitrides selected from the group including TiN_x, where x is equal to or greater than 1, and ZrN.

2. A layer system according to claim 1, wherein said first layer comprises oxides selected from the group including:

SnO_x, x is equal to or less than 2, ZrO₂, ZnO, Ta₂ O₅, NiCr-oxide, TiO₂, Sb₂ O₃, In₂ O₃, and mixed oxides from oxides of this group.

3. The layer system according to claim 1, wherein the layer system is applied to a substrate composed of glass, and wherein said first layer comprises SnO_y, y is equal to or less than 2;

said second layer comprises TiN_x, x is equal to or greater than 1;

said third layer comprises SnO_z ;

z is equal to or less than 2;

said fourth layer comprises TiN_w, w is equal to or greater than 1;

said fifth layer comprises Al₂ O₃ ;

and wherein said layer system further comprises a backside layer, applied to a side of the substrate opposite from the observer, comprising TiN_u, u is equal to or greater than 1.

4. A layer system according to claim 3, wherein x equals 2;

y equals 1.05;

z equals 2;

w equals 1.05; and

u equals 1.05.

5. The layer system according to claim 1, wherein said layer system is applied to a substrate composed of glass, and wherein said first layer comprises SnO_y, y is equal to or less than 2;

said second layer comprises TiN_x, x is equal to or greater than 1;

said third layer comprises SnO_z, z is equal to or less than 2;

said fourth layer comprises TiN_w, w is equal to or greater than 1;

said fifth layer comprises Al₂ O₃ ;

and wherein said layer system further comprises an adhesive layer, arranged between said first layer and said second layer, comprising NiCrO_x ;

and wherein said layer system further comprises a backside layer, arranged on a side of the substrate opposite from the observer, comprising TiN_u, u is equal to or greater than 1.

6. A layer system according to claim 5, wherein x equal 2;

y equals 1.05;

z equals 2;

w equals 1.05; and

u equal 1.05.

7. The layer system according to claim 1, wherein said layer system is applied to a substrate composed of glass, and wherein said first layer comprises SnO_y, y is equal to or less than 2;

said second layer comprises TiN_x, x is equal to or higher than 1;

said third layer comprises SnO_z, z is equal to or less than 2;

said fourth layer comprises TiN_w, w is equal to or greater than 1;

said fifth layer comprises SiO₂ ;

and said layer system further comprises an adhesive layer, arranged between said first and said second layers, comprising a material selected from the group including NiCr and NiCr-suboxide;

and said layer system further comprises a backside layer, applied to a side of the substrate opposite from the observer, comprising TiN_u, u is equal to or greater than 1.

8. A layer system according to claim 7, wherein x equal 2;

y equals 1.05;

z equals 2;

w equals 1.05; and

u equals 1.05.

9. The layer system according to claim 1, wherein the substrate is composed of glass, and wherein said first layer comprises NiCr-suboxide, functioning as dielectric and as an adhesive;

said second layer comprises TiN_x, x is equal to or greater than 1;

said third layer comprises SnO_y, y is equal to or less than 2;

said fourth layer comprises TiN_z, z is equal to or greater than 1;

said fifth layer comprises Al₂ O₃ ;

and said layer system further comprises a backside layer, applied to a side of the substrate opposite of the observer, comprising TiN_w, w is equal to or more than 1.

10. A layer system according to claim 9, wherein x equals 1.05;

y equals 2;

z equals 1.05; and

w equals 1.05.

11. The layer system according to claim 1, wherein said layer system is applied to a substrate composed of glass, and wherein said first layer comprises NiCr-suboxide, functioning as dielectric and as an adhesive;

said second layer comprises TiN_x, x is equal to or greater than 1;

said third layer comprises SnO_y, y is equal to or less than 2;

said fourth layer comprises TiN_w, w is equal to or greater than 1;

said fifth layer comprises SiO₂ ;

and said layer system further comprises a backside layer, applied to a side of the substrate opposite to the observer, comprising TiN_z, z is equal to or greater than 1.

12. A layer system according to claim 11, wherein x equals 1.05;

y equals 2;

w equals 1.05; and

z equals 1.05.

13. The layer system according to claim 1, wherein said layer system is applied to a substrate composed of glass, with a refractive index of n=1.52, wherein said first layer comprises SnO_y, y is equal to or less than 2, and has a thickness of 170 angstrom;

said second layer comprises TiN_x, x is equal to or greater than 1, and has a thickness of 190 angstrom;

said third layer comprises SnO_z, z is equal to or less than 2, and has a thickness of 500 angstrom;

said fourth layer comprises TiN_w, w is equal to or greater than 1, and has a thickness of 130 angstrom; and

said fifth layer comprises Al₂ O₃, and has a thickness of 730 angstrom.

14. The layer system according to claim 1, wherein the substrate is composed of glass with a refractive index of n=1.52, and wherein said first layer comprises SnO_y, y is equal to or less than 2, and has a thickness of 170 angstrom;

said second layer comprises TiN_x, x is equal to or greater than 1, and has a thickness of 175 angstrom;

said third layer comprises SnO_z, z is equal to or less than 2, and has a thickness of 500 angstrom;

said fourth layer comprises TiN_w, w is equal to or greater than 1, and has a thickness of 110 angstrom; and

said fifth layer comprises Al₂ O₃, and has a thickness of 730 angstrom.

15. A layer system according to claim 1, wherein x equals 1.05.

16. A layer system according to claim 1, wherein said second layer comprises TiN_x, x is equal to or greater than one.

17. A layer system according to claim 16, wherein said fourth layer comprises TiN_x, x is equal to or greater than 1.

18. An anti-reflective layer system for substrates comprising:

a first layer arranged on the substrate on a side of the substrate toward an observer, functioning as a dielectric and comprising metal oxide;

a second layer arranged on said first layer, comprising nitride;

a third layer arranged on said second layer, functioning as a dielectric and comprising metal oxide;

a fourth layer arranged on said third layer, comprising nitride;

and a fifth layer arranged on said fourth layer, functioning as a dielectric and comprising metal oxide;

wherein said third layer comprises oxides selected from the group including;

SnO_x, x is equal to or less than 2, ZrO₂, ZnO, Ta₂ O₅, Nicro-oxide, TiO₂, Sb₂ O₃, In₂ O₃ and mixed oxides from oxides of this group.

19. A layer system according to claim 18, wherein said fifth layer comprises oxides selected from the group:

SiO₂, Al₂ O₃, AlSi-oxide, NiSi-oxide, MgO and oxide fluorides from this group.

20. A layer system according to claim 18, wherein x equals 2.

21. An anti-reflective layer system for substrates comprising:

a first layer arranged on the substrate on a side of the substrate toward an observer, functioning as a dielectric and comprising metal oxide;

a second layer arranged on said first layer, comprising nitride;

a third layer arranged on said second layer, functioning as a dielectric and comprising metal oxide;

a fourth layer arranged on said third layer, comprising nitride;

and a fifth layer arranged on said fourth layer, functioning as a dielectric and comprising metal oxide;

wherein said fourth layer comprises nitrides selected from the group TiN_x, where x is equal to or greater than 1, and ZrN.

22. A layer system according to claim 21, wherein said fifth layer comprises a material with a refractive index n is equal to or smaller than 1.7.

23. A layer system according to claim 21, wherein x equals 1.05.

24. An anti-reflective layer system for substrates comprising:

a first layer arranged on the substrate on a side of the substrate toward an observer, functioning as a dielectric and comprising metal oxide;

a second layer arranged on said first layer, comprising nitride;

a third layer arranged on said second layer, functioning as a dielectric and comprising metal oxide;

a fourth layer arranged on said third layer, comprising nitride;

and a fifth layer arranged on said fourth layer, functioning as a dielectric and comprising metal oxide;

wherein said fifth layer comprises MgF₂.

25. An anti-reflective layer system for substrates comprising:

a first layer arranged on the substrate on a side of the substrate toward an observer, functioning as a dielectric and comprising metal oxide;

a second layer arranged on said first layer, comprising nitride;

a third layer arranged on said second layer, functioning as a dielectric and comprising metal oxide;

a fourth layer arranged on said third layer, comprising nitride;

and a fifth layer arranged on said fourth layer, functioning as a dielectric and comprising metal oxide;

wherein said layer system further comprises an adhesive layer arranged between said first layer and said second layer.

26. A layer system according to claim 25, wherein said adhesive layer comprises a material selected from the group including Ni and NiO_x, x is less than 1.

27. A layer system according to claim 25, wherein said adhesive layer comprises a material selected from the group including:

Cr, Cr-suboxide, and NiCr alloy.

28. A layer system according to claim 25, wherein said adhesive layer comprises a NiCr alloy, with said alloy comprising 80 weight percent Ni and 20 weight percent Cr, Cr selected from Cr and Cr-suboxide.

29. An anti-reflective layer system for substrates comprising:

a first layer arranged on the substrate on a side of the substrate toward an observer, functioning as a dielectric and comprising metal oxide;

a second layer arranged on said first layer, comprising nitride;

a third layer arranged on said second layer, functioning as a dielectric and comprising metal oxide;

a fourth layer arranged on said third layer, comprising nitride;

and a fifth layer arranged on said fourth layer, functioning as a dielectric and comprising metal oxide;

wherein said first layer comprises NiCr-suboxide functioning also as an adhesive.

30. An anti-reflective layer system for substrates comprising:

a first layer arranged on the substrate on a side of the substrate toward an observer, functioning as a dielectric and comprising metal oxide;

a second layer arranged on said first layer, comprising nitride;

a third layer arranged on said second layer, functioning as a dielectric and comprising metal oxide;

a fourth layer arranged on said third layer, comprising nitride;

and a fifth layer arranged on said fourth layer, functioning as a dielectric and comprising metal oxide;

wherein said layer system is applied to a substrate composed of glass, and wherein said first layer has a thickness of 170 angstrom ±

20%;

said second layer has a thickness of 170 angstrom ±

20%;

said third layer has an optical thickness of 5550/4 angstrom ±

20%;

said fourth layer has a thickness of 110 angstrom ±

20%;

and said fifth layer has an optical thickness of 5550/4 angstrom ±

10%;

such layer thicknesses selected with the cited thickness tolerances taking into account the interdependence between the layer thicknesses and materials selected for the layers.

31. An anti-reflective layer system for substrates comprising:

a first layer arranged on the substrate on a side of the substrate toward an observer, functioning as a dielectric and comprising metal oxide;

a second layer arranged on said first layer, comprising nitride;

a third layer arranged on said second layer, functioning as a dielectric and comprising metal oxide;

a fourth layer arranged on said third layer, comprising nitride;

and a fifth layer arranged on said fourth layer, functioning as a dielectric and comprising metal oxide; and

further comprising a backside layer, applied to a back side of the substrate not facing the observer, said backside layer comprising TiN_x, X is equal to or greater than 1.

32. A layer system according to claim 31, wherein the substrate is composed of glass having a thickness of 2 mm, and a refractive index n=1.52;

and

said backside layer and has a thickness of 70 angstrom;

said first layer comprises SnO_y, y is equal to or less than 2, having a thickness of 170 angstrom and a refractive index n=2.05;

said second layer comprises TiN_z, z is equal to or greater than 1, having a thickness of 190 angstrom;

said third layer comprises SnO_w, w is equal to or smaller than 2, having a thickness of 500 angstrom and a refractive coefficient n=2.05;

said fourth layer comprises TiN_u, u is equal to or greater than 1, and having a thickness of 130 angstrom; and

said fifth layer comprises Al₂ O₃, having a thickness of 730 angstrom, and a refractive index n=1.6.

33. A layer system according to claim 31, wherein said substrate is composed of glass, has a thickness of 2 mm and a refractive index n=1.52;

said backside layer has a thickness of 70 angstrom;

said first layer comprises NiCr-suboxide, having a thickness of 170 angstrom and a refractive index n=2.1;

said second layer comprises TiN_y, y is equal to or greater than 1, having a thickness of 170 angstrom;

said third layer comprises SnO_w, w is equal to or less than 2, having a thickness of 500 angstrom and a refractive coefficient n=2.05;

said fourth layer comprises TiN_z, z is equal to or greater than 1, and having a thickness of 110 angstrom; and

said fifth layer comprises SiO₂, having a thickness of 730 angstrom and a refractive index n=1.5.

34. A layer system according to claim 31, wherein said backside layer has a thickness in the range from 40 to 200 angstrom, and a surface resistance of 150 to 500 ohms per square.

35. A layer system according to claim 34, wherein said surface resistance is approximately 450 ohm per square.

36. A layer system according to claim 31, wherein x equals 1.05.

37. A method for manufacturing a coating for an optically effective layer system for substrates, the coating having an anti-reflective effect, comprising the following steps:

on a side of the substrate which faces an observer, apply a first layer functioning as a dielectric and comprising metal oxide;

apply a second layer covering said first layer comprising TiN_x, where x is equal to or greater than 1;

apply a third layer covering said second layer, functioning as a dielectric and comprising metal oxide;

apply a fourth layer covering said third layer, comprising TiN_x, where x is equal to or greater than 1;

apply a fifth layer covering said fourth layer, functioning as a dielectric, and comprising metal oxide;

wherein said layers are applied using a DC-reactive sputtering method from targets with a magnetron.

38. A method according to claim 37, wherein the substrate is composed of glass, and wherein a layer is generated composed of NiCr-suboxide, via reactive sputtering from a target comprising NiCr comprising 80 weight percent Ni, 20 weight percent Cr, with said magnetron, in the presence of a sputtering gas mixture comprising Ar and O₂, using a pressure of approximately 5×

10^-3 mbar.

39. A method according to claim 37, wherein a chemical vapor deposition method is employed.

40. A method for manufacturing a coating for an optically effective layer system for substrates, the coating having an antireflective effect, comprising the following steps:

on a side of the substrate which faces an observer, apply a first layer functioning as a dielectric and comprising metal oxide;

apply a second layer covering said first layer comprising nitride;

apply a third layer covering said second layer, functioning as a dielectric and comprising metal oxide;

apply a fourth layer covering said third layer, comprising nitride;

apply a fifth layer covering said fourth layer, functioning as a dielectric, and comprising metal oxide;

wherein said layers are applied using a DC-reactive sputtering method from targets with a magnetron;

wherein the substrate is composed of glass, and wherein at least one of said layers is generated composed of SnO_x, x is equal to or less than 2, via reactive sputtering from a Sn target with said magnetron, in the presence of a sputtering gas mixture comprising Ar and O₂, using a pressure of approximately 5×

10^-3 mbar.

41. A method for manufacturing a coating for an optically effective layer system for substrate, the coating having an antireflective effect, comprising the following steps:

on a side of the substrate which faces an observer, apply a first layer functioning as a dielectric and comprising metal oxide;

apply a second layer covering said first layer comprising nitride;

apply a third layer covering said second layer, functioning as a dielectric and comprising metal oxide;

apply a fourth layer covering said third layer, comprising nitride;

apply a fifth layer covering said fourth layer, functioning as a dielectric, and comprising metal oxide;

wherein said layers are applied using a DC-reactive sputtering method from targets with a magnetron;

wherein the substrate is composed of glass, and wherein a layer is generated composed of SiO₂, by reactive sputtering from an Si-target with said magnetron, in the presence of a sputtering gas mixture comprising Ar and O₂, using a pressure of approximately 5×

10^-3 mbar.

42. A method for manufacturing a coating for an optically effective layer system for substrates, the coating having an antireflective effect, comprising the following steps:

on a side of the substrate which faces an observer, apply a first layer functioning as a dielectric and comprising metal oxide;

apply a second layer covering said first layer comprising nitride;

apply a third layer covering said second layer, functioning as a dielectric and comprising metal oxide;

apply a fourth layer covering said third layer, comprising nitride;

apply a fifth layer covering said fourth layer, functioning as a dielectric, and comprising metal oxide;

wherein said layers are applied using a DC-reactive sputtering method from targets with a magnetron;

wherein the substrate is composed of glass, and wherein a layer is generated composed of Al₂ O₃, via reactive sputtering from an Al-target with said magnetron, in the presence of a sputtering gas mixture comprising Ar and O₂, using a pressure of approximately 5×

10^-3 mbar.

43. A method for manufacturing a coating for an optically effective layer system for substrates, the coating having an antireflective effect, comprising the following steps:

on a side of the substrate which faces an observer, apply a first layer functioning as a dielectric and comprising metal oxide;

apply a second layer covering said first layer comprising nitride;

apply a third layer covering said second layer, functioning as a dielectric and comprising metal oxide;

apply a fourth layer covering said third layer, comprising nitride;

apply a fifth layer covering said fourth layer, functioning as a dielectric, and comprising metal oxide;

wherein said layers are applied using a DC-reactive sputtering method from targets with a magnetron;

wherein the substrate is composed of glass, and wherein a layer is generated composed of TiN_x, x is equal to or greater than 1, via reactive sputtering from a Ti-target with said magnetron, in the presence of a sputtering gas mixture comprising Ar and N₂, using a pressure of approximately 5×

10^-3 mbar.

44. A method for manufacturing a coating for an optically effective layer system for substrates, the coating having an antireflective effect, comprising the following steps:

on a side of the substrate which faces an observer, apply a first layer functioning as a dielectric and comprising metal oxide;

apply a second layer covering said first layer comprising nitride;

apply a third layer covering said second layer, functioning as a dielectric and comprising metal oxide;

apply a fourth layer covering said third layer, comprising nitride;

apply a fifth layer covering said fourth layer, functioning as a dielectric, and comprising metal oxide;

wherein said layers are applied using a DC-reactive sputtering method from targets with a magnetron;

wherein a plasma-supported chemical vapor deposition method is employed.

45. A method for manufacturing a coating for an optically effective layer system for substrates, the coating having an antireflective effect, comprising the following steps:

on a side of the substrate which faces an observer, apply a first layer functioning as a dielectric and comprising metal oxide;

apply a second layer covering said first layer comprising nitride;

apply a third layer covering said second layer, functioning as a dielectric and comprising metal oxide;

apply a fourth layer covering said third layer, comprising nitride;

apply a fifth layer covering said fourth layer, functioning as a dielectric, and comprising metal oxide;

wherein said layers are applied using a DC-reactive sputtering method from targets with a magnetron;

wherein a pyrolyse method is employed.

46. An antireflective layer system for substrates comprising:

a first layer arranged on the substrate on a side of the substrate toward an observer, functioning as a dielectric and comprising metal oxide;

a second layer arranged on said first layer, comprising nitride;

a third layer arranged on said second layer, functioning as a dielectric and comprising metal oxide;

a fourth layer arranged on said third layer, comprising nitride;

and a fifth layer arranged on said fourth layer, functioning as a dielectric and comprising metal oxide;

wherein said first layer comprises oxides selected from the group including;

SnO_x, x is equal to 2, ZrO₂, ZnO, Ta₂ O₅, NiCr-oxide, TiO₂ Sb₂ O₃, In₂ O₃, and mixed oxides from oxides of this group.

47. An antireflective layer system for substrates comprising:

a first layer arranged on the substrate on a side of the substrate toward an observer, functioning as a dielectric and comprising metal oxide;

a second layer arranged on said first layer, comprising nitride;

a third layer arranged on said second layer, functioning as a dielectric and comprising metal oxide;

a fourth layer arranged on said third layer, comprising nitride;

and a fifth layer arranged on said fourth layer, functioning as a dielectric and comprising metal oxide;

wherein said fifth layer has a surface resistance, on a surface facing the observer, of 100 to 400 ohm per square.

48. A layer system according to claim 47, wherein said surface resistance is approximately 150 ohm per square.