Method for producing a multilayer coating and device for carrying out said method

• US 20060151312A1
• Filed: 12/03/2003
• Published: 07/13/2006
• Est. Priority Date: 12/04/2002
• Status: Active Grant

• Current Assignee: Leybold Optics GmbH (Buhler Holding AG)
• Original Assignee: Leybold Optics GmbH (Buhler Holding AG)
• Inventors: Hagedorn, Harro, Deppisch, Gerd, Lehnert, Walter, Scherer, Michael, Pistner, Jurgen, Roder, Mario
• Granted Patent: US 8,956,511 B2
• Time in Patent Office: Days
• US Class Current: 204/192.120
• CPC Class Codes: C23C 14/0078 by moving the substrates between spatially separate sputtering and reaction stations
• CPC Class Codes: C23C 14/0094 in transition mode
• CPC Class Codes: C23C 14/024 Deposition of sublayers, e.g. to promote adhesion of the coating C23C14/027 takes precedence
• CPC Class Codes: C23C 14/08 Oxides C23C14/10 takes precedence
• CPC Class Codes: C23C 14/547 using optical methods
• CPC Class Codes: H01J 2237/3321 CVD [Chemical Vapor Deposition]
• CPC Class Codes: H01J 37/34 operating with cathodic sputtering H01J37/36 takes precedence ; methods of cathodic sputtering C23C14/34
• CPC Class Codes: H01J 37/3405 Magnetron sputtering
• CPC Class Codes: H01J 37/3473 Composition uniformity or desired gradient
• CPC Class Codes: H01J 37/3476 Testing and control

Abstract

A method for producing one or more coating on a displaccable substrate in a vacuum chamber with the aid of a residual gas, by means of a sputtering device said coating being formed from at least two constituents, whereby a sputtering material of the sputtering device constitutes at least one first constituent and a reactive component of the residual gas constitutes a second constituent. The method comprises the following steps: reactive deposition of a coating on the substrate by the addition of a reactive component, with a predetermined stoichiometric deficit of the reactive component in a zone of the sputtering device; displacement of the substrate with the deposited coating into the vicinity of a plasma source, which is located in the vacuum chamber at a predetermined distance from the sputtering device; modification of the structure and/or stoichiometry of the coating by the action of the plasma of the plasma source, preferably by the addition of a predetermined quantity of the reactive component, to reduce the optical loss of the coating. The aim of the invention is to reduce the optical loss of the multilayer coating to below a predetermined value in a zone of the second coating adjoining the first coating. To achieve this, an interface is created with a thickness d₁ and a value for the deficit of the reactive component DEF that is less than a value DEF₁.

Claims

1-54. -54. (canceled)

55. A method for producing a coating on a moving substrate in a vacuum chamber with a residual gas employing a sputtering apparatus, wherein said coating is formed from at least two constituents, a first constituent is a sputter material of said sputtering apparatus and a second constituent is a reactive component of said residual gas, the method comprising the steps of:

reactive depositing, with a delivery of said reactive component, said coating on said substrate with a given stoichiometric deficit of said second constituent in a spatial area of said sputtering apparatus;

moving said substrate with said deposited coating in a spatial area of a plasma source which is arranged in said vacuum chamber at a predetermined distance from said sputtering apparatus; and

modifying a structure and/or stoichiometry of said coating via a plasma action by said plasma source with an input of a predetermined amount of said reactive component to reduce an optical loss of said coating.

56. A method for producing a coating on a moving substrate in a vacuum chamber with a residual gas employing a sputtering apparatus, wherein said coating is formed from at least two constituents, a first constituent is a sputter material of said sputtering apparatus and a second constituent is a reactive component of said residual gas, the method comprising the steps of:

reactive depositing, with a delivery of said reactive component, said coating on said substrate in a spatial area of said sputtering apparatus, said coating being of a predetermined coating thickness and having an optical loss below a predetermined minimum;

moving said substrate with said deposited coating in a spatial area of a plasma source which is arranged in said vacuum chamber at a given distance from said sputtering apparatus; and

modifying a structure and/or stoichiometry of said coating via a plasma treatment by said plasma source while supplying a predetermined amount of said reactive component to reduce an optical loss in said coating.

57. The method of claim 56, further comprising the step of operating said sputtering apparatus at a working point on a characteristic line or a characteristic map in accordance with said sputter material and a reactive gas material.

58. The method of claim 56, further comprising the step of optically monitoring said coating to adjust optical properties of said coating after a deposit of said predetermined coating thickness.

59. The method of claim 56, further comprising the step of optically monitoring said coating to adjust optical properties of said coating after said plasma treatment of said coating by said plasma source.

60. The method of claim 56, further comprising the step of optically monitoring said coating to adjust optical properties of said coating after a deposit of said predetermined coating thickness and after said plasma treatment of said coating by said plasma source.

61. The method of claim 58, wherein the step of optically monitoring comprises the step of detecting transmission, reflection and/or loss at one or more wavelengths of said coating.

62. The method of claim 56, further comprising the step of regulating said sputtering apparatus in accordance with a monitoring signal from an optical monitor apparatus.

63. The method of claim 56, further comprising the step of regulating said plasma source in accordance with a monitoring signal from an optical monitor apparatus.

64. The method of claim 58, further comprising the step of performing optical monitoring at predetermined times and/or predetermined coating thicknesses.

65. The method of claim 56, further comprising the step of increasing the content of said reactive component in said coating to a stoichiometric composition.

66. The method of claim 56, wherein the step of reactive depositing comprises the step of depositing said coating with a preset deficit between 0 and 100% of said reactive component with respect to said reactive component of said residual gas.

67. The method of claim 56, further comprising the step of regulating a partial pressure of said reactive component a gas flow of said reactive component and/or by an electric power of said sputtering apparatus.

68. The method of claim 56, further comprising the step of regulating a sputtering cathode voltage of said by a gas flow of said reactive component.

69. The method of claim 56, further comprising the step of regulating the quotient of a sputtering rate to a partial pressure of said reactive component a sputtering power.

70. The method of claim 69, further comprising the step of determining the quotient from the quotient of a first line intensity and a second line intensity, said first line intensity being a measure of said sputtering rate and said second line intensity being a partial pressure of said reactive component.

71. The method of claim 56, wherein said reactive component is oxygen, carbon and/or nitrogen.

72. The method of claim 56, further comprising the step of substantially independently establishing partial pressures of said reactive component in the area of said sputtering apparatus and said plasma source.

73. The method of claim 56, wherein the step of modifying comprises the step of generating a plasma action by said plasma source with a plasma which contains at least said reactive component.

74. The method of claim 56, wherein the step of modifying comprises the step of modifying said coating to a stoichiometric compound by the substoichiometric composition.

75. The method of claim 56, further comprising the step of carrying said substrate at a predetermined velocity past said plasma source and/or said sputtering apparatus.

76. The method of claim 56, further comprising the step of moving said substrate past said plasma source and/or said sputtering apparatus at a variable speed.

77. The method of claim 56, further comprising the step of moving said substrate repeatedly past said sputtering apparatus and/or said plasma source.

78. The method of claim 56, further comprising the step of controlling or regulating a gas flow of said reactive component in accordance with optical properties of said coating.

79. The method of claim 56, further comprising the step of applying heat to said substrate before, during or after the step of modifying.

80. The method of claim 56, further comprising the step of controlling or regulating a gas flow of said reactive component in accordance with a deposited coating thickness and/or a duration of the modifying step and/or a number of passages past said plasma source.

81. The method of claim 56, wherein said sputtering apparatus comprises a magnetron-supported cathode sputtering source.

82. The method of claim 56, further comprising the step of operating said sputtering apparatus with an alternating electrical field.

83. A method for preparing a multilayer coating with at least one reactively operated coating apparatus and at least one reaction apparatus in a vacuum chamber, comprising the steps of:

depositing a second layer with reactive component on at least one substrate moving relative to said coating apparatus or said reaction apparatus;

modifying structure and/or stoichiometry of at least one layer with said reaction apparatus; and

performing a build-up of an interface layer with a thickness d₁ and a value of a deficit of said reactive component DEF smaller than a value DEF₁ in a region adjoining a first layer to reduce optical loss in said multilayer coating below a predetermined value.

84. The method of claim 83, further comprising the steps of obtaining values of a momentary thickness d(t) of said second layer during the deposition of said second layer and performing the deposition of said second layer with a value of the deficit of said reactive component DEF greater than DEF₁ as soon as d(t) is greater than d₁.

85. The method of claim 83, further comprising steps of:

producing at least one layer of said multilayer coating on a moving substrate in a vacuum chamber with a residual gas employing a sputtering apparatus, wherein said multilayer coating is formed from at least two constituents, a first constituent is a sputter material of said sputtering apparatus and a second constituent is a reactive component of said residual gas;

reactive depositing, with a delivery of said reactive component, said multilayer coating on said substrate with a given stoichiometric deficit of said second constituent in a spatial area of said sputtering apparatus;

moving said substrate with said deposited coating in a spatial area of a plasma source which is arranged in said vacuum chamber at a predetermined distance from said sputtering apparatus; and

modifying a structure and/or stoichiometry of said coating via a plasma action by said plasma source while supplying a predetermined amount of said reactive component to reduce an optical loss of said multilayer coating.

86. The method of claim 83, further comprising the step of preparing said multilayer coating where one of said first or second layer is low-refracting layer comprising SiO₂ and other of said first or second layer is high-refracting layer comprising at least one of the following:

Nb₂O₅ or Ta₂O₅.

87. The method of claim 86, further comprising the step of preparing multilayer coating where said high-refractive layer comprises Nb₂O₅, said low-refracting layer comprises SiO₂, and said interface layer has said thickness d₁ of 2.5-10 nm and the deficit of said reactive component DEF₁ is less than 0.5.

88. The method of claim 83, further comprising the step of selecting a diminishing value of the deficit of said reactive component DEF, for a given thickness d₁ of said interface layer, as the rate of deposition increases.

89. The method of claim 83, wherein the step of performing builds-up a number of interfaces between high-refracting and low-refracting coatings N₁ greater than 3.

90. The method of claim 83, wherein the step of depositing utilizes a magnetron source system;

and wherein the step of modifying utilizes a plasma source.

91. The method of claim 83, further comprising the step of changing texture and/or stoichiometry of said multilayer coating after depositing a layer with a given layer density.

92. Apparatus for producing a coating on a substrate with a sputtering apparatus in a vacuum chamber with a residual gas, said coating being formed from at least two constituents and at least a first constituent is a sputter material of said sputtering apparatus and at least a second constituent is a reactive component of said residual gas, comprising:

a device for reactive depositing said coating on said substrate while feeding a reactive component with a predetermined stoichiometric deficit in the vicinity of said sputtering apparatus;

a device for moving said substrate with said deposited coating in the vicinity of a plasma source which is arranged in said vacuum chamber at a predetermined distance from said sputtering apparatus; and

a device for modifying texture and/or stoichiometry of said coating via a plasma treatment by said plasma source while supplying a predetermined amount of the reactive component to reduce an optical loss in said coating.

93. Apparatus for producing a coating on a substrate by with a sputtering apparatus in a vacuum chamber with a residual gas, said coating being formed of at least two components, and at least a first constituent is a sputter material from said sputtering apparatus and at least a second constituent is a reactive component of said residual gas, comprising:

a device for reactive depositing said coating on said substrate in the vicinity of said sputtering apparatus while supplying a reactive component with an optical loss falling below a minimum at a given coating thickness;

a device for moving said substrate with said deposited coating in the vicinity of a plasma source which is arranged in said vacuum chamber at a predetermined distance from said sputtering apparatus; and

a device for modifying structure and/or stoichiometry of said coating via a plasma treatment by said plasma source while supplying a predetermined amount of the reactive component to reduce an optical loss in said coating.

94. The apparatus of claim 93, further comprising a gas supply and/or a pump unit arranged in the vicinity of said sputtering apparatus and said plasma source and having a pass-through for at least one substrate.

95. The apparatus of claim 93, wherein said substrate is arranged on a turntable spaced away from said sputtering apparatus and said plasma source.

96. The apparatus of claim 95, wherein several substrates are arranged on said turntable.

97. The apparatus of claim 95, wherein said sputtering apparatus and said plasma source are arranged to correspond to the circumference of said turntable.

98. The apparatus of claim 93, further comprising at least two sputtering apparatus disposed diametrically opposite one another.

99. The apparatus of claim 98, wherein said plasma source is arranged spatially between said two sputtering apparatus.

100. The apparatus of claim 98, further comprising an optical measuring device, arranged spatially between said two sputtering apparatus, for measuring an optical transmission, reflection and/or loss of said coating deposited on said substrate.

101. The apparatus of claim 98, further comprising at least one optical measuring apparatus disposed spatially between said two sputtering apparatus.

102. The apparatus of claim 100, wherein said optical measuring apparatus is an one-wavelength or multiple wavelength photometer and/or ellipsometer.

103. The apparatus of claim 93, further comprising a heating system, arranged at least in an area of said vacuum chamber, for heating said substrate.

104. The apparatus of claim 93, wherein said sputtering apparatus is a magnetron-supported cathode sputtering source.

105. The apparatus of claim 93, wherein said sputtering apparatus is operated with an alternating electric field in a high-frequency, medium-frequency or pulsed DC range.

106. The apparatus of claim 93, wherein said plasma source is one of the following:

an electron-cyclotron-wave-resonance (ECWR) source, a Hall End plasma source, a hot cathode DC plasma source, a high-frequency plasma source, a medium-frequency or pulsed DC plasma source.

107. Apparatus for producing a multilayer coating, comprising:

at least one reactively operated coating apparatus;

at least one reaction apparatus in a vacuum chamber; and

a control system; and

wherein said coating apparatus is operable to deposit a second layer with at least one reactive component on at least one substrate moving relative to said coating apparatus and said reaction apparatus;

wherein said reaction apparatus is operable to change texture and/or stoichiometry of at least one layer; and

wherein said control system is operable to control said coating apparatus and said reaction apparatus to form an interface layer, in a region of said second layer adjoining a first layer, with a thickness d₁ and a value of a deficit of said reactive component DEF lower than a value DEF 1 to reduce an optical loss in said multilayer coating below a predetermined value.

108. A multilayer coating produced with at least one reactively operated coating apparatus and at least one reaction apparatus in a vacuum chamber by a method comprising the steps of:

depositing a second layer with reactive component on at least one substrate moving relative to said coating apparatus or said reaction apparatus;

modifying structure and/or stoichiometry of at least one layer with said reaction apparatus; and

performing a build-up of an interface layer with a thickness d₁ and a value of a deficit of said reactive component DEF smaller than a value DEF₁ in a region adjoining a first layer to reduce optical loss in said multilayer coating below a predetermined value.