SPUTTERING SOURCE

Abstract

A sputtering source includes two facing plate shaped targets and a magnet arrangement along each of the targets. An open coating outlet area from the reaction space between the targets is limited by facing rims of the two plate shaped targets. Catcher plates along each of the rims respectively project in a direction from the rims towards each other into the open coating outlet area, thereby restricting the open coating outlet area as limited by the mutually facing rims of the two plate shaped targets.

Claims

1-53. (canceled)

54. A sputtering source conceived to sputter coat a substrate comprising: two plate shaped targets extending along respective plate-planes, the sputtering surfaces of said targets facing each other thereby defining, in between, a reaction space, said plate-planes being mutually parallel or mutually inclined by at most 90; an anode arrangement; a magnet arrangement along each of said targets and opposite to the respective sputtering surfaces, each magnet arrangement generating a magnetic field in said reaction space impinging on and/or emanating from and distributed along at least a predominant part of the respective sputtering surfaces; an open coating outlet area from said reaction space, limited by respective areas of mutually facing rims of said two plate shaped targets; said sputtering surfaces of said targets transiting into respective side surface areas of said targets along said mutually facing rims by respective transition surface areas of said targets, said transition surface areas having a smaller radius of curvature than the adjacent areas of the respective sputtering surface; a catcher plate arrangement along each of said rims and distant from the respective one of said targets and respectively projecting in a direction from said rims towards each other into said open coating outlet area, thereby restricting said open coating outlet area as limited by said mutually facing rims of said two plate shaped targets.

55. The sputtering source of claim 54 constructed to sputter coat said substrate with an oxide.

56. The sputtering source of claim 54 wherein said projecting catcher plate arrangement has an overall surface which predominantly consists of a first surface area and of a second surface area, said first surface area being exclusively exposed to said reaction space whereas said second surface area being exclusively exposed to a space opposite said reaction space with respect to said open coating outlet area.

57. The sputtering source of claim 54 wherein each catcher plate arrangement has a most projecting rim and a distance from said most projecting rim to a side surface of the respective target, measured in a plane parallel to the respective plate plane and perpendicularly to the length extent of said most projecting rim, is smaller than a distance between said most projecting rim and a surface of the respective target, measured in a plane perpendicular to said respective plate plane and perpendicular to said length extent of said most projecting rim.

58. The sputtering source of claim 54 said plate-planes being symmetrical to a central plane.

59. The sputtering source of claim 54 said plate-planes being parallel.

60. The sputtering source of claim 54 wherein said mutually facing rims are linear and parallel.

61. The sputtering source of claim 54 wherein said plate shaped targets are rectangular or square.

62. The sputtering source of claim 54 said plate-planes being symmetrical to a central plane, said open coating outlet area extending along a plane perpendicular to said central plane.

63. The sputtering source of claim 54 at least one of said targets comprising an oxide or consisting of an oxide.

64. The sputtering source of claim 54 comprising an oxygen gas feed arrangement discharging into said reaction space and/or downstream said restricted open coating outlet area, restricted by said catcher plate arrangements.

65. The sputtering source of claim 54 comprising a gas feed arrangement discharging into said reaction space and/or downstream said restricted open coating outlet area, restricted by said catcher plate arrangements.

66. The sputtering source of claim 54 said catcher plate arrangements comprise catcher plates of at least one of the following shapes: plane, bent towards said reaction space, bent away from said reaction space.

67. The sputtering source of claim 54 wherein at least one of said catcher plate arrangements comprises at least one metal plate or consists of at least one metal plate or comprises at least one ceramic material plate or consists of at least one ceramic material plate.

68. The sputtering source of claim 54 said anode arrangement comprising a lateral anode plate, complementing the two-side delimitation of said reaction space by said two targets to a three-side delimitation of said reaction space.

69. The sputtering source of claim 68 comprising two of said lateral anode plates complementing the two-side delimitation of said reaction space by said two targets to a four-side delimitation of said reaction space.

70. The sputtering source of claim 54 said anode arrangement comprising a lateral anode plate, complementing the two-side delimitation of said open coating outlet area by said two targets to a three-side delimitation of said open coating outlet area.

71. The sputtering source of claim 70 said anode arrangement comprising two of said lateral anode plates, complementing the two-side delimitation of said open coating outlet area by said two targets to a four-side delimitation of said open coating outlet area.

72. The sputtering source of claim 54, said anode arrangement comprising an anode plate opposite to said open coating outlet area with respect to said reaction space.

73. The sputtering source of claim 54 said anode arrangement comprising an anode frame around said open coating outlet area.

74. The sputtering source claim 54 said anode arrangement comprising an arrangement of anode strips along the border of said targets and exclusively along said mutually facing rims.

75. The sputtering source of claim 54 said anode arrangement comprising an arrangement of anode strips along said mutually facing rims, said catcher plate arrangements comprising projecting metal plates electrically and mechanically connected to said anode strips.

76. The sputtering source of claim 54 said catcher plate arrangements comprising projecting metal plates electrically connected to said anode arrangement.

77. The sputtering source of claim 54 said catcher plate arrangements being two legs of a frame limiting and around said open coating outlet area.

78. The sputtering source of claim 54 said magnetic field being generated uni-directionally from one sputtering surface to the other sputtering surface.

79. The sputtering source of claim 54 comprising a third target covering said reaction space opposite said open coating outlet area.

80. The sputtering source of claim 79 said third target being associated with a magnet arrangement generating along the sputter surface of said third target a magnetron magnetic field.

81. The sputtering source of claim 54 at least one of said targets comprising or consisting of at least one of the metals In, Sn, Zn, Ga, Al.

82. A sputter coating chamber comprising at least one sputtering source according to claim 54 and further comprising a substrate holder constructed to hold a substrate with one of its extended surfaces exposed to the surrounding atmosphere, said substrate holder being mounted in said sputter coating chamber in a position in which said extended surface faces said restricted open coating outlet area and visibility of said transition surface areas from at least a predominant part of said extended surface is bared by said catcher plate arrangements.

83. The sputter coating chamber of claim 82 wherein said substrate on said substrate holder is operated in an electrically floating manner or is connectable to a DC reference potential.

84. The sputter coating chamber of claim 82 said substrate holder being constructed to hold a circular substrate and is operationally connected a rotary drive, rotating said substrate holder about a central axis.

85. The sputter coating chamber of claim 82 comprising a substrate-holder-carrier with at least two of said substrate holders, the number of said sputtering sources provided being equal or different from the number of said at least two substrate holders on said carrier.

86. A sputtering system comprising at least one sputtering source according to 54, further comprising a substrate holder and a gas feed arrangement delivering a gas into the reaction space of said at least one sputtering source, and/or between the open coating outlet area of said sputtering source and said substrate holder.

87. The system of claim 86 wherein said gas feed arrangement is in operational flow connection with a gas reservoir arrangement containing a gas, said gas or at least one component thereof being oxygen.

88. A method of sputter coating a substrate with a material, at least one component thereof being present in the sputtering plasma as a ion, or of manufacturing substrate coated with said material, the methods comprising applying said coating by means of at least one sputtering source according to claim 54.

89. The method according of claim 88 comprising blocking by said catcher plate arrangements of said sputtering source ions having an energy of at least 0.5 UACe from impinging on said substrate, wherein UAC is the time-average of the absolute value of the anode/target voltage.

Description

[0084] The Figures show:

[0085] FIG. 1 shows most generically and simplified, in a cross-sectional representation, an embodiment of a sputtering source according to the invention, which may be built in a sputtering chamber according to the invention, as well as in a system according to the invention, to perform the manufacturing method of the invention,

[0086] FIG. 2a to FIG. 2d: schematically, different rim shapes of targets of the sputtering source according to the invention,

[0087] FIG. 3: schematically, two targets of different plate shapes, of an embodiment of the sputtering source according to the invention,

[0088] FIG. 4: schematically, two targets of different plate shapes, of an embodiment of the sputtering source according to the invention, with liner and parallel neighboring rims,

[0089] FIG. 5: schematically, two targets of an embodiment of the sputtering source according to the invention;

[0090] FIG. 6 to FIG. 9: schematically, two targets of four embodiments of the sputtering source according to the invention with respective mutual positioning of the targets;

[0091] FIG. 10: schematically, a rim portion of a target of an embodiment of the sputtering source according to the invention, cooperating with a substrate in a sputter chamber according to the invention;

[0092] FIG. 11: schematically, a top view on an embodiment of the sputtering source according to the invention, with an anode arrangement;

[0093] FIG. 12: schematically, a side view on an embodiment of the sputtering source according to the invention, with an anode arrangement;

[0094] FIG. 13: schematically, a perspective view of an embodiment of the sputtering source according to the invention, with an anode arrangement;

[0095] FIG. 14: schematically, an embodiment of the sputtering source according to the invention, with an anode arrangement;

[0096] FIG. 15: schematically, an embodiment of the sputtering source according to the invention;

[0097] FIG. 16: schematically, an embodiment of the sputtering source according to the invention;

[0098] FIG. 17: schematically, an embodiment of the sputtering source according to the invention in more details;

[0099] FIG. 18: schematically, an embodiment of the sputtering source according to the invention with an additional target;

[0100] FIG. 19 and FIG. 20: schematically, a side and a top view on a part of an embodiment of a sputter chamber according to the invention;

[0101] FIG. 21 and FIG. 22: schematically, and in representations in analogy to those of FIGS. 19 and 20, an embodiment of a sputter chamber according to the invention;

[0102] FIG. 23 and FIG. 24: schematically, and in representations in analogy to those of FIGS. 21 and 22, an embodiment of a sputter chamber according to the invention;

[0103] FIG. 25 and FIG. 26: schematically, and in representations in analogy to those of FIGS. 23 and 24, an embodiment of a sputter chamber according to the invention;

[0104] FIG. 27: a schematic representation of an embodiment of the sputter chamber according to the invention and of different possibilities of electric supplying.

[0105] As most schematically shown in FIG. 1, the sputtering source 1 in the addressed embodiment comprises, within a vacuum tight enclosure 3, a first target 5 and a second target 7. Each of the targets is plate shaped and extends along a respective plate-plane E.sub.5, E.sub.7. The sputtering surfaces S.sub.5 and S.sub.7 face each other. In the embodiment shown in FIG. 1 the plate-planes E.sub.5, E.sub.7 are mutually inclined whereby the angle of mutual inclination is at most 90. In another embodiment, the plate-planes E.sub.5 and E.sub.7 are parallel. The sputtering surfaces S.sub.5 and S.sub.7 delimit, in between, two sides of a reaction space R.

[0106] The targets 5 and 7 have each a rim portion 9 and 10, which are neighboring each other and face towards each other. These two rim portions 9 and 10 two-side delimit an open coating-material outlet area 12 represented in FIG. 1 by hatched line. Along these rim portions which delimit the open coating-material outlet area 12 of the sputtering source 1, the respective sputtering surfaces S.sub.5 and S.sub.7 transit into side surfaces L.sub.5 and L.sub.7 by respective transition surface areas T.sub.5 and T.sub.7, highlighted in FIG. 1 by dashed circles.

[0107] Dependent on the shape and orientation of the side surfaces L.sub.5 and L.sub.7 of the targets 5 and 7, the transition areas T.sub.5 and 1.sub.7 may exhibit different radii r of curvature. Nevertheless, such radii r are always smaller than the radius of curvature of the adjacent areas of the respective sputtering surfaces S.sub.5 and S.sub.7 which is, if this adjacent area is plane, infinite. The radii r of curvature are considered in a cross sectional view perpendicularly through the respective elongated rim portions 9 and 10 of the targets 5 and 7 and perpendicularly to the sputtering surfaces S.sub.5 and S.sub.7.

[0108] FIGS. 2a to 2e show different examples of rim portions 9, 10 of the targets 5, 7.

[0109] According to FIG. 2a the sputtering surface S.sub.5,7 transits in the side surface L.sub.5,7 which extends perpendicularly to the sputtering surface S.sub.5,7 via the transition surface area T.sub.5,7 realized as an edge with a radius of curvature r.sub.a.

[0110] According to FIG. 2b the sputtering surface S.sub.5,7 transits in the side surface L.sub.5,7, which is inclined to the sputtering surface by an angle smaller than 90 via the transition surface area T.sub.5,7 realized as gently bent surface area with a radius of curvature r.sub.b.

[0111] According to FIG. 2c the sputtering surface S.sub.5,7 transits in the side surface L.sub.5,7, which is rolling from the sputtering surface S.sub.5,7 via the transit surface area T.sub.5,7 realized as gently bent surface area with a radius of curvature r.sub.c.

[0112] According to FIG. 2d the sputtering surface S.sub.5,7 transits in the side surface L.sub.5,7, which has a polygonal profile form via multiple transit surface area T.sub.1,5,7 to T.sub.3,5,7 realized by edges of respective small radii of curvature r.sub.1,2,3.

[0113] According to FIG. 2e the sputtering surface S.sub.5,7 transits in the side surface L.sub.5,7, which is shaped as an arc of a circle from the sputtering surface. In this case the transit surface and the side surface L.sub.5,7, are identical, realized with one radius of curvature r.sub.e.

[0114] As may be seen there exists always along the rim portions 9 and 10, delimiting the open coating material outlet area 12 at least one transition surface area T which has a radius of curvature as defined above which is smaller than the radius of curvature of the sputtering surfaces adjacent and along the rim portions 9,10.

[0115] Under the general aspect of the sputtering source 1 according to the invention, and as shown in the embodiment of FIG. 1 the plate shaped targets 5,7 need not be of equal plate shape. One thereof may e.g. be circular, the other elliptical. Nevertheless in a today realized embodiment and as will be addressed later, both plate-shaped targets are of equal shape, namely of rectangular or square shape. Further and even if the plate-shaped targets 5,7 are of different shape, in one embodiment, in fact also realized at the today practiced embodiment with rectangular or square targets, at least the rim portions 9 and 10 extend linearly in the y direction shown in FIG. 1 and are, in a further embodiment, parallel.

[0116] Further and independent of the shape of the plate-shaped targets 5, 7 along their extended sputter surfaces S.sub.5,7 the rim 9 portion of the one target 5 may be shaped differently from the rim portion 10 of the target 7, considered in cross sectional representation as e.g. shown in FIG. 2.

[0117] The sputtering source 1 further comprises respective anode arrangements 14.sub.5 and 14.sub.7, which may be combined to one single anode arrangement 14, operative for both targets 5 and 7.

[0118] Please note that the anode blocks shown in FIG. 1 do not represent the locations and shapes of anodically operated members in the sputtering source 1 but do merely address presence of respective anodes. The anode arrangement 14.sub.5 and 14.sub.7 or 14 may be electrically supplied via feed-troughs 16.sub.5,7 as shown in FIG. 1. Alternatively or additionally the enclosure 3 may act as an anode with respect to the targets, operated as cathodes.

[0119] In any case, electrically operating the anode arrangement 14, 14.sub.5, 14.sub.7 and the plate-shaped targets 5,7 as cathodes results in an electric field EF on the sputtering surfaces S.sub.5 and S.sub.7.

[0120] As was addressed above, the inventors have recognized, that particles which originate from sputtering in the transition surface area as ions, or which pass as ions nearby the transition surface area impinge with substantially higher energies on the overall substrate, than other particles out of the reaction space.

[0121] In one possible explanation of this phenomenon, this electric field EF is more closely to be considered along the rim portions 9 and 10. As represented in FIG. 2a the strength of electric field EF which impinges perpendicularly on the sputtering surfaces S.sub.5,7 and which is customarily represented by the density of field lines, has a local maximum along the transition surface areas T.sub.5,7 due to their reduced radius r of curvature. As known to the skilled artisan, this local maximum EF.sub.T of the strength of the electric field EF becomes the more pronounced the smaller that the radius r of curvature at the transition surface area is selected, relative to the radius of curvature of the area of the sputtering surface just adjacent the transition surface area. This radius is in fact infinite if the addressed sputtering surface is plane.

[0122] Thus and as there exists always along the rim portions 9 and 10, delimiting the open coating material outlet area 12, at least one transition surface area T which has a radius of curvature smaller than the radius of curvature of the sputtering surfaces along the rim portions 9, 10, there exists always a local maximum of electric field strength along the addressed rim portions 9, 10.

[0123] This local maximum of electric field strengths may be one reason of the addressed phenomenon.

[0124] Another or an additional reason may be that the energetic ions are accelerated in the reaction space. In a normal operation, the strongest electric field is found in the vicinity of the targets. There the electric field is perpendicular to the target. Therefore, the majority of those energetic ions potentially reaching the substrate start their trajectories perpendicularly to the target surface in the vicinity of which they were first accelerated. These ions can have their trajectory deflected and be repelled by negative potentials, as for example by another target. Thus most of those ions could bounce between both targets multiple time until leaving the reaction area. However for energetic ions generated in the vicinity of the transition area or energetic ions deflected in the transition area, the local curvature of the transition area makes that those energetic ions trajectories are more likely to directly point towards the substrate and are therefore more likely to reach it.

[0125] Under this explanation too the shapes of the targets in this transition areas have therefore an impact upon the path of the energetic ions towards the substrate and therefore ultimately upon the quantity of energetic ions reaching the substrate.

[0126] The targets 5, 7 are operatively linked to respective magnet arrangements 18.sub.5 and 18.sub.7 which generate through the reaction space R a magnetic field B along at least a predominant part of the sputtering surfaces S.sub.5 and S.sub.7. Under the generic approach according to FIG. 1, this magnetic field B may be unbalanced B.sub.ub with respect one or to each target 5,7, may be bidirectional at each of the targets, may extend bidirectionally from one target to the other target or may extend uni-directionally from one target to the other target. Latter is realized in the today practiced embodiment.

[0127] By the sputtering source substrates 104 shall be coated with an oxide layer. Therefor at least one of the targets 5,7 is of a metal-oxide and/or there is provided a gas feed arrangement (not shown in FIG. 1) feeding oxygen gas into the reaction space R and/or downstream the open coating-material outlet area 12 along the substrate 104 to be coated in the sputtering chamber 100. The sputtering source 1 according to the invention is mounted, as schematically shown in FIG. 1 at 102, to the sputtering chamber 100.

[0128] The sputtering source 1 further comprises a catcher plate arrangement 20.sub.7 and 20.sub.5 along each of and distant from the rim portions 10 and 9 of the respective targets 7,5.

[0129] The catcher plate arrangements 20.sub.5 and 20.sub.7 extend all along the rim portions 9 and 10 respectively and project from the respective targets or their plate-planes E.sub.5,7 towards each other. With respect to the reaction space R they are positioned opposite the open coating material outlet area 12 and thus in fact restrict or downsize the open area of the open coating-material outlet area 12 which is open towards the substrate 104.

[0130] Within the sputtering chamber 100 there is provided a substrate holder 106 which is constructed to hold and position the substrate 104, at least during sputter-coating operation by the sputtering source 1, in coating position. This coating position is distant from and opposite the restricted open coating material outlet area 12, restricted by the catcher plate arrangements 20.sub.5,7.

[0131] The catcher plate arrangements 20.sub.5,7, the substrate holder 106 are mutually positioned so, that the transition surface areas T.sub.5,7 are invisible from any point of or at least the predominant part of the exposed surface 108 of the substrate 104. The catcher plate arrangements block all lines of sight from any point or at least of the addressed predominant part of the surface 108 to the transition surface areas T.sub.5,7.

[0132] In FIG. 1 the space blocked by the respective catcher plate arrangements is schematically shown by dash-dotted lines at C.

[0133] As was already addressed high-energy particles impinging on the surface 108 during its sputter-coating cause local damage to the overall substrate. The occurrence of such damages is avoided by catching these high energy particles by means of the catcher plate arrangements 20.sub.5,7.

[0134] Additionally, local damages to the substrate 104 and/or to the oxide layer on surface 108 may also be caused by flaking off of particles from sputter coated members of the sputtering source 1, the thickness thereof increasing during maintenance intervals.

[0135] Therefore and as may be seen from the embodiment of FIG. 1 those surfaces of the catcher plate arrangements 20.sub.5,7 which are exposed to sputter coating from the reaction space R are not exposed, are hidden from the surface 108 of the substrate and thus from the substrate holder 104. Vice versa, those surfaces of the catcher plate arrangements, which are exposed to the surface 108 of the substrate 104 and thus to the substrate holder 106, are not exposed and thus hidden from the reaction space R.

[0136] After having explained the sputtering source 1 and the sputtering chamber 100 in generic terms and with the help of the FIGS. 1 and 2 we will address different embodiments specifically in context with specific features of the source and/or chamber.

[0137] 1. Shape of the Plate-Shaped Targets 5,7:

[0138] As we have already addressed above the plate shape of the one target may be different from the plate shape of the other target. Thus e.g. a circular target 5 may cooperate witch an elliptical target 7.

[0139] In today practiced embodiment both targets have a linear extended rim portion 9, 10. Such linearly extended rim portions may be provided irrespective of the overall plate shapes of the respective targets, as shown in FIG. 3 or FIG. 4 showing the targets 5 and 7 of different shapes with linearly extended rim portions 9, 10 schematically and in a perspective view.

[0140] In the today practiced embodiment the linearly extended rim portions 9 and 10 are additionally parallel. Such parallelism may also be practiced irrespective of the plate shape of the plate-shaped targets 5, 7 as schematically shown in FIG. 4.

[0141] In today practiced embodiment both targets are rectangular plates, and are, additionally, of equal extent, as shown in the embodiment of FIG. 5.

[0142] 2. Mutual Orientation of the Plate-Shaped Targets 5,7

[0143] As shown in FIG. 1 and schematically represented in FIG. 6 the plate-planes E.sub.5,7 of the mutually facing targets 5,7 may be mutually inclined by an angle . This inclination angle is at most 90. As shown in the addressed figures and due to this inclination angle, the reaction space R becomes in such embodiment narrower towards the open coating material outlet area 12.

[0144] In the embodiment of FIG. 7 the plate-planes E.sub.5,7 and the targets 5,7 are again mutually inclined by the inclination angle of at most 90 but the reaction space is widened towards the open coating-material outlet area 12.

[0145] In the embodiment of FIG. 8 the plate-planes E.sub.5,7 are parallel, parallel to a central plane E.sub.Z, which accords with the embodiment as practiced today.

[0146] In the embodiment of FIG. 9 the plate-planes E.sub.5,7 are parallel, parallel to a central plane E.sub.Z and the rim portions 9,10 extend in a plane E.sub.9,10 which is perpendicular to the central plane E.sub.Z.

[0147] 3. Oxide-Deposition, Material of Targets 5, 7

[0148] So as to sputter deposit oxide layers on the substrate 104, two basic possibilities prevail.

[0149] The first one is to exploit targets of different or equal oxide material. The second one is to exploit both targets of same or different metals and to react the respectively sputtered off metals in an oxygen containing atmosphere in the reaction space R and/or in the space S (see FIG. 1) of the sputtering chamber 100 between the open coating-material outlet area 12 and the substrate holder 106. Both possibilities may be combined e.g. by exploiting one target of an oxide material, the second of a metal and reacting the sputtered off materials in the reaction space R and/or in the space S between the open coating-material outlet area 12 and the substrate 104 on the substrate holder 106 of the sputtering chamber 100.

[0150] Further one target considered may be of different materials, e.g. one section of a metal, a second section of an oxide. This is schematically shown in FIG. 5 by the dash-dotted sections M.sub.1 and M.sub.2 at target 5.

[0151] Deposition of oxide layers with as few as possible damages is particularly important in depositing TCO, Transparent, Conductive Oxide layers, as e.g. used in context with manufacturing of opto-electric devices as of LED devices or photovoltaic devices.

[0152] Particularly layers of ITO, ZnO, GZO are today of high interest. Thus and with an eye on the addressed possibilities for deposition the oxide layers in the respective embodiments of the sputtering source 1, the targets 5,7 comprise or consist of at least one of the metals In, Sn, Zn, Ga, Al and/or of at least one oxide of at least one of these metals. If purely reactive sputter coating is applied from sputtered metal, oxygen gas or an oxygen containing gas is fed to at least one on the reaction space R and of the chamber space S. For mixed oxide deposition one target may be of the one metal, as of In or Ga the other of the second metal as of Sn or Zn and/or of an oxide.

[0153] Also a mixed target type may be applied where e.g. the inner section M.sub.1 of the target is e.g. Sn and the outer section M.sub.2 is e.g. of Zn or of SnO.

[0154] 4. Catcher Plate Arrangements 20.sub.5,7

[0155] The catcher plate arrangements 20.sub.5,7 extend each all along and distant from the rim portions 9 and 10 of the targets 5,7. Each may be of a single plate member or of more than one plate member mounted one subsequent the other along and distant from the respective rim portion 9,10. To fulfill the object of catching high energy particles originating from sputtering of or bypassing nearby the transition surface areas T.sub.5,7 of the targets 5,7 the catcher plate arrangements 20.sub.5,7 may be of any desired material which withstands thermal loading by the sputtering process. Especially if the oxide coating material is an electrically insulating material, ceramic material may be used for at least a part of the catcher plate arrangements 20.sub.5,7. Nevertheless, in one embodiment, at least the predominant part of the catcher plate arrangements 20.sub.5,7 is of metal.

[0156] Made of metal, the catcher plate arrangements 20.sub.5,7 may be operated on respectively desired electric potential e.g. on DC-, pulsed DC- or AC- as of RF-potential. The electric potentials applied to the catcher plate arrangements 20.sub.5,7 may be equal for both arrangements 20.sub.5 and 20.sub.7, or may be different. If at least one of the catcher plate arrangements 20.sub.5,7 is built from separate metal plates, a desired electric potential distribution may be applied along such catcher plate arrangement. Nevertheless, and as often most high energy particles from the transition surface areas T.sub.5,7 are still negative ions when they arrive at the catcher plate arrangements, in one embodiment both catcher plate arrangements 20.sub.5,7 of metal are operated on a positivei.e. an anodic-electric DC potential with respect to the targets 5,7. In one embodiment both catcher plate arrangements 20.sub.5,7 are operated on the common anode potential of the common anode arrangement 14. In another embodiment one catcher plate arrangement 20.sub.5 is operated on the potential of the associated anode arrangement 14.sub.5 and/or the second catcher plate arrangement 20.sub.7 is operated on the potential of the associated anode arrangement 14.sub.7.

[0157] The catcher plate arrangements 20.sub.5,7, are plane plates or sets of plane plates or of plates bent towards the reaction space R as shown in FIG. 1 at catcher plate arrangement 20.sub.7 and/or of plates bentas shown in FIG. 10from the reaction space R away towards the chamber space S. The catcher plate arrangements 20.sub.5,7 project towards each other, and thus restrict the area of the open coating-material outlet area 12 remaining open towards the space S and thus towards the substrate 104 on the substrate holder 106. The catcher plate arrangements 20.sub.5,7 restrict the open coating-material outlet area 12 just by a degree high enough to bar or block the addressed visibility between the transition surface areas T.sub.5,7 and the predominant part of the extended surface 108 of a the substrate 104 on the substrate holder 106, even to the entire extended surface 108.

[0158] With the help of FIG. 10 a geometric relationship shall be explained. This is done with the help of FIG. 10 but it must be emphasized, that the following explanations are valid for all embodiments of the invention. Each of the catcher plate arrangements 20.sub.7 has an extended most projecting rim or border 20.sub.mp.

[0159] A distance of this most projecting rim 20.sub.mp to the respective side surface 9,10 of the respective target is shown by d. This distance is measured parallel to the respective plate plane E.sub.5 or E.sub.7 respectively and perpendicularly to the extent of the most projecting rim 20.sub.mp which extents substantially in a direction perpendicular to the plane of FIG. 10.

[0160] A further distance of the most projecting rim 20.sub.mp to the respective target 7,5 is shown by D. This distance is measured in a plane perpendicular to the respective plate plane E.sub.5, E.sub.7 and again, as was defined, perpendicular to the extent of the most projecting rom.

[0161] There is valid in all embodiments of the invention:

dD

and in a good embodiment

d<D.

[0162] One should thereby keep in mind that surfaces of the catcher plate arrangements 20.sub.5,7 which are exposed to both, the reaction space R and the extended surface 108 should be kept minimal or even vanishing. This because, as was addressed above, the surfaces of the catcher plate arrangements exposed to the reaction space R will become coated with a coating thickness increasing with operation time of the sputtering source. If these surfaces are also exposed to the extended surface 108 of the substrate 104, flaking off may result in damaging the overall substrate. In one embodiment the catcher plate arrangements 20.sub.5,7 are constructed and mounted as maintenance exchange parts.

[0163] 5. Anode Arrangement 14, 14.sub.5,7

[0164] FIG. 11 shows, schematically and simplified, a top view of one embodiment of the sputtering source 1. The anode arrangement 14 comprises at least one, in the embodiment of FIG. 11two anode lateral plates 14.sub.a and 14.sub.b, which complement the delimitation of the reaction space R, two side delimitated by the targets 5 and 7, to a four side delimitation. If, considered in z direction, the two anode lateral or side plates 14.sub.a and 14.sub.b extend down to or are located just adjacent the rim portions 9 and 10, they complement the delimitation of the open coating material outlet area 12, two side delimitated by the rim portions 9 and 10, to a four side delimitation. Only one lateral plate e.g. plate 14.sub.a may be provided e.g. if the wall of the sputtering source is operated as anode and is located laterally nearby the targets, at the location and instead of lateral plate 14.sub.b of FIG. 11.

[0165] Clearly if only one lateral plate is provided, respectively the reaction space and the open coating material outlet area becomes three side delimitated by such single lateral plate.

[0166] FIG. 12 shows, schematically and simplified, a side view in analogy to that of FIG. 1, on an embodiment of the sputtering source 1. In this embodiment the anode arrangement 14 comprises a top anode plate 14.sub.c opposite to the open coating-material outlet area 12, with respect to the reaction space R. If such a top plate 14.sub.c is combined with a single lateral plate e.g. 14.sub.a then the anode arrangement becomes L-profiled, combined with two lateral plates 14.sub.a and 14.sub.b, U-profiled.

[0167] In the embodiment as shown schematically and simplified in FIG. 13, the embodiments of FIGS. 11 and 12 are combined and complemented. The anode arrangement comprises, similar to a one side open box, the side plates 14.sub.a and 14.sub.b, the top plate 14.sub.c, and further plates 14.sub.d5 and 14.sub.d7 extending behind the targets 5 and 7 and behind the respective magnet arrangements 18.sub.5,7. The catcher plate arrangements 20.sub.5,7 are not shown in FIG. 13, for clearness sake.

[0168] In a further embodiment of the sputtering source 1 as shown schematically and simplified by the side view of FIG. 14, the anode arrangement comprises respective anode strips 14.sub.e7 and 14.sub.e5 which run exclusively along and distant from the rim portions 9 and 10. In this embodiment the catcher plate arrangements 20.sub.5,7 may be directly mounted to the anode strips 14.sub.e5 and 14.sub.e7 and are thereby, if made of metal, operated on the electric anode potential. Please note that anode strips frame like all around the borders of the targets are not provided.

[0169] In one embodiment as shown schematically and simplified in the perspective view of the sputtering source 1 according to FIG. 15, having equally square shaped targets 5 and 7, the embodiment of FIG. 13 is combined with the embodiment of FIG. 14. The catcher plate arrangements 20.sub.5,7 of metal are directly mounted to the anode strips 14.sub.e5 and 14.sub.e7. They may be of one piece with the anode strips.

[0170] As shown in FIG. 15 in dash-dotted lines, the strip shaped catcher plate arrangements 20.sub.5,7 may be the legs of a catcher plate arrangement frame 20.sub.a. Such a catcher plate arrangement frame 20.sub.a may be applied in all embodiments of the sputtering source 1. Thereby the four legs of such frame may be of equal or different materials. Each leg may comprise or consist of at least one metal plate, comprise or consist at least one ceramic material plate.

[0171] 6. Magnetic Field B and Magnet Arrangements 18.sub.5 and 18.sub.7

[0172] Different patterns of magnetic field B may be established in the reaction space R.

[0173] In one embodiment of the sputtering source 1 the magnetic field pattern has at least a part of the magnetic field unbalanced, impinging on or emanating from only one respective sputtering surface S.sub.5 and/or S.sub.7. Such unbalanced field components are addressed schematically in FIG. 1 at B.sub.ub. The magnetic field pattern may instead or additionally to unbalanced components, comprise components emanating at one sputtering surface and impinging at the second sputtering surface and also vice versa, thus being bi-directionally directed between the sputtering surfaces S.sub.5,7 as schematically shown in FIG. 1 at B.sub. and B.sub.+.

[0174] Further the magnetic field may comprise or consist of uni-directional field components, the magnetic field being exclusively directed from one specific sputtering surface e.g. from S.sub.5 to the second sputtering surface, as of S.sub.7.

[0175] The magnetic field pattern may even be tailored along at least one of the sputtering surfaces as a magnetron magnetic field, as perfectly known to the skilled artisan, such at least one target being then operated as a magnetron target (not shown).

[0176] Irrespective whether the magnetic field pattern consists or comprises unbalanced components and/or bi-directional components and/or uni-directional components and/or magnetron-type components, the magnetic field pattern may be swept or wobbled in the reaction space R by providing at least one of the magnet arrangements 18.sub.5,7 controllably moved with respect to the sputtering surfaces e.g. behind and along the sputtering surfaces S.sub.5,7, as schematically shown in FIG. 1 by the double arrows P.

[0177] An embodiment of the sputtering source 1 at which the magnetic field pattern is uni-directional, exclusively from one sputtering surface S.sub.5 to the other S.sub.7, is schematically and simplified shown in FIG. 16. Such an embodiment has revealed, with respect to the pattern of magnetic field B in the reaction space R, as highly effective and of relatively simple realization.

[0178] Behind each of the targets 5,7 a two dimensional pattern of permanent magnets 19.sub.5 and 19.sub.7 is mounted. The magnet dipoles D (from N to S) are directed perpendicular to the respective plate-planes E.sub.5 and E.sub.7 and point at one target towards, at the other target from the sputtering surface S.sub.5,7.

[0179] A magnet joke 21 of ferromagnetic material interconnects the two patterns 19.sub.5,7 along which additional permanent magnets may be provided as shown in dash line at 19.sub.21. The magnet joke may additionally be exploited to electrically supply the two targets 5 and 7 e.g. from a supply connection S.

[0180] 7. Embodiment of the Sputtering Source 1 as Realized Today

[0181] In FIG. 17 there is shown, schematically and simplified, a cross section through a sputtering source 1 as realized today. The same reference numbers are used for parts which have already been addressed.

[0182] In one embodiment the two plate-shaped targets 5 and 7 are equally shaped. They are square and parallel and the rim portions 9 and 10 are positioned in a plane. Opposite the sputtering surfaces S.sub.5,7 each target 5,7 is in thermal contact with a respective cooling plate 23.sub.5,7 with cooling-medium lines 25.sub.5,7 for a liquid or gaseous cooling medium.

[0183] Opposite the targets 5, 7, with respect to the cooling plates 23.sub.5,7, the patterns of permanent magnets 19.sub.5,7 are provided with dipole directions as indicated at D. The patterns 19.sub.5,7 of permanent magnets are magnetically linked by the magnet joke 21. Additional permanent magnets 19.sub.21 may be provides along the magnet joke 21, as shown in dashed line in FIG. 17.

[0184] With the exception of the open coating-material outlet area 12, restricted by the catcher plate arrangements 20.sub.5,7 the targets 5,7, the cooling plates and the magnet joke are surrounded by the anode arrangement 14 with the anode plates 14.sub.d5, 14.sub.d7, the top plate 14.sub.c, the lateral plates 14.sub.b, and 14.sub.a, as well as the anode strips 14.sub.e5 and 14.sub.e7. The catcher plate arrangements 20.sub.5,7 are mechanically and electrically connected to the anode strips 14.sub.e5 and 14.sub.e7.

[0185] Electric supply feed-troughs 30.sub.5, 30.sub.7 are provided through the magnet joke 21 and the anode plate 14c for electrically supplying the targets 5 and 7.

[0186] With the two feed-throughs 30.sub.5, 30.sub.7 both targets 5,7 may be electrically supplied independently from one another.

[0187] If both targets are to be equally electrically supplied, one single feed trough suffices and the magnetic joke may additionally be exploited as electrical feed line towards the targets. Further a gas feed line 24 for a working gas and/or oxygen discharges in the reaction space R.

[0188] The catcher plate arrangements 20.sub.5,7 may form the two legs of a frame 20 as has already been addressed in context with FIG. 15 and shown in FIG. 17 in dash line.

[0189] As schematically shown in FIG. 17 in dash line a third target 8 may be provided opposite the open coating-material outlet area 12. Providing such cover target 8 may be realized in all embodiments of the sputtering source 1.

[0190] 8. Three Target 5,7,8 Sputtering Source 1

[0191] In FIG. 18, schematically and simplified, an example is shown of a three-target embodiment of a sputtering source 1 according to the invention. The same reference numbers are used for same elements as up to now. There is provided opposite to the open coating-material outlet area 12 a third covering target 8 with sputtering surface S.sub.8, cooling plate 23.sub.8 and pattern 19.sub.8 of permanent magnets. Thereby the third target 8 may be conceived as a magnetron with magnetron magnetic field B.sub.mag.

[0192] In FIG. 18 the electric- and gas-feed-troughs are not shown.

[0193] In FIG. 18, the two parts 2T.sub.5 and 21.sub.7 of the magnet joke 21 may be separated by an air gap AG.

[0194] 9. Sputtering Chamber 100 in Different Embodiments

[0195] 9.1 Single Source/Single Substrate Chamber

[0196] FIGS. 19 and 20 show a single sputtering source 1/single substrate 104 sputtering chamber 100. Thereby, only the mutual arrangement of the targets 5 and 7, of the catcher plate arrangement 20.sub.5 and 20.sub.7 and of the substrate 104 are shown. As shown in FIG. 19, at least the predominant part of the extended surface 108 of the circular substrate 104 is bared with respect to visibility to the respective transition surface areas T.sub.5,7. This predominant part may be the complete extended surface area 108 of the substrate 104. Nevertheless it may be that some boarder areas 105, as shown in FIGS. 19 and 20 in dashed lines, may still be exposed to the addressed transition surface areas, under the consideration of low probability that high energy particles will impinge on such outermost peripheral areas 105 of the substrate 104.

[0197] In this embodiment the sputtering source 1 is exemplified having equally shaped, rectangular targets 5 and 7. The open coating-material outlet area 12 extends along a plane parallel to the holder plane along which the substrate 104 is held on the substrate holder 106. The open coating-material outlet area 12 is centralized with respect to the central axis A of the substrate 104 and of the substrate holder 106 and faces the extended surface 108 of the substrate 104 and thus the substrate holder 106. The substrate 104 is rotated by a drive (not shown in FIGS. 19, 20) rotating the substrate holder 106 about the central axis A. The targets 5 and 7 are stationary as schematically shown at Q.

[0198] 9.2 Multiple Source/Single Substrate Chamber 100

[0199] Both FIGS. 21 and 22 show schematically and most simplified a side-view and a top-view on a four-source 1, single substrate 104 sputtering chamber 100. In this embodiment the open coating-material outlet areas 12 of the sputtering sources 1 are inclined by an angle with respect to the plane along which the substrate 104 is supported on the substrate holder 106. Thereby, and with an inclination angle

045

[0200] the coating thickness homogeneity along the extended surface 108 of the substrate 104 is improved. Again and as schematically shown by drive 107, the substrate holder 106 may be rotated about its central axis A and therewith the substrate 104.

[0201] Clearly, less than four or more than four sources 1 may be provided to commonly sputter-coat the surface 108 of the one substrate 104 with one or more than one oxide layers.

[0202] 9.3 Batch Sputter Chamber 100

[0203] FIGS. 23 and 24 show in a representation in analogy to those of the FIGS. 21 and 22 a four-sputtering source 1/four-substrate 104 batch sputtering chamber 100. The four substrates 104 are first loaded on a multiple substrate holder carrier 106.sub.a in a loading/unloading positon I, as shown by the load/unload double-arrow U/L. Together with the multiple-substrate holder carrier 106.sub.a the batch of substrates 104 is lifted in coating position II within sputtering chamber 100. There, different possibilities are operational: [0204] a) Each substrate 104 is aligned with one of the sputtering sources 1 and is there rotated about its central axis A as shown at . Thus, in fact, each substrate of the batch is treated as a single substrate according to FIGS. 19 and 20. Once the batch of substrates 104 is coated, the multiple substrate holder carrier 106.sub.a is moved downwards from coating position II in loading/unloading position I. [0205] b) The multiple substrate holder carrier 106.sub.a is as well rotated about its central F axis as shown at by which the homogeneity of the thickness of the deposited oxide layer on the substrates 104 may be improved. [0206] c) Rotation co of the substrates 104 is avoided by replacing the one source 1 at the coating position of the substrates 104 by multiple sputtering source (not shown).

[0207] Nevertheless, as all substrates 104 are simultaneously treated, the respective sputtering chamber of this embodiment is a batch sputtering chamber.

[0208] Clearly, the embodiment according to FIGS. 23 and 24 may be realized in variants for batches of less or of more than four substrates 104 and with more or less than four sputtering sources 1.

[0209] 9.4 in-Line Sputter Chamber 100

[0210] FIGS. 25 and 26 show in a representation in analogy to those of the FIGS. 23 and 24 a sputtering chamber 100 conceived as an inline sputtering chamber. There are provided seven sputtering sources 1 distributed along a circle. The multiple substrate holder carrier 106.sub.a is constructed to hold eight circular substrates 104 on respective substrate holders evenly distributed along its periphery. In a first position (a) of the multiple substrate holder carrier 106.sub.a and as schematically shown in FIG. 26, substrates are unloaded and loaded from/to one of the substrate holders 106 on the carrier 106.sub.a. Loading and unloading operation lasting 0.5 each. If is the in-line clock period, in one clock period one substrate holder 106 is unloaded and reloaded.

[0211] With the clock period i the multiple substrate holder carrier 106.sub.a is rotated according to stepwise so that each substrate 104, once loaded in position (a), is stepped seven times to sputter coating subsequently by the seven sputtering sources 1. Once a substrate has passed the seven sputtering sources 1 it is unloaded in position (a) and an uncoated substrate is loaded. Taken the case where all the seven sputtering sources 1 coat the substrates 104 with an equally thick oxide layer, then the substrates are finally coated with an oxide layer of 7 the thickness deposited by each of the sputtering sources 1. The throughput has nevertheless the rate 1/. Sputter coating one substrate by one sputtering source with same thickness would necessitate a sputtering time of 7. The throughput rate would be 1/7. Thus, by using such an inline sputtering chamber 100, the time duration of the overall sputter coating process may be tailored largely independently from the step-rate of the inlying machine.

[0212] Here too rotation of the substrate may be avoided by replacing the single sputtering sources 1 at the coating positions of the substrates 104 by multiple sputtering sources commonly coating a respective substrate.

[0213] 10. Electric Feed of the Sputter Chamber 100

[0214] In FIG. 27 there is most schematically shown the two targets 5 and 7 of the sputtering source 1, the substrate holder 104 of the sputter chamber 100 with substrate 106, the catcher plate arrangements 20.sub.5 and 20.sub.7 and the target-specific anode arrangements 14.sub.7 and 14.sub.5. In block 122.sub.7 the different possibilities of electrically supplying the target 7 with respect to the specific anode arrangement 14.sub.7 is schematically represented by the possibility selecting switches W which represents the possibilities to supply the target 7 with respect to the anode arrangement 14.sub.7 in at least one of the manners (a), (b), (c).

[0215] In option or manner (a) the target 7/anode arrangement 14.sub.7 is electrically supplied by a DC supply source 122.sub.a. According to option (b) the target 7 is operated with respect to the anode arrangement 14.sub.7 by a pulsed DC source 122.sub.b.

[0216] According to option (c) the target 7 is operated with respect to the anode arrangement 14.sub.7 by a RF supply source 122.sub.c. Two or three of the supplies may be combined, e.g. DC with pulsed DC, Pulsed DC with RF etc. Thereby and as schematically represented by the option block 124 the addressed supply sources 122.sub.a to 122.sub.c may be operated in a floating manner or with respect to a reference potential, e.g. the anode potential being ground potential.

[0217] The second target 5 may be electrically supplied with respect to the anode arrangement 14.sub.5 with the same possibilities or options as just addressed for electrically supplying the target 7 with respect to the anode arrangement 14.sub.7. Target 5 may also be directly connected over the joke or an electrical connection with the target 7. Therefore, in FIG. 27, the respective possibilities for electrically supplying target 5 with respect to anode arrangement 14.sub.5 are not shown.

[0218] The two targets 5 and 7 may be electrically supplied separately by different supply possibilities (a) to (c) and in a floating manner or referred to a reference potential or the two targets/anodes may be electrically supplied equally, i.e. according to option (a) and/or (b) and/or (c) floatingly or referred to a reference potential. Then the two anode arrangements 14.sub.5 and 14.sub.7 may be combined to one anode arrangement 14 and the two targets 5 and 7 may both be operated by a common electric supply.

[0219] In todays' embodiment which was addressed above, the two targets 5 and 7 are both operated by a common DC and RF supply source with respect to a common anode arrangement 14. Thereby the anode is operated at ground reference potential.

[0220] FIG. 27 shows further in block 126 and in a representation in analogy to that which was used to explain the possibilities of electrically supplying the targets 5 and 7 with respect to the anode arrangement, four options (a) to (d) for operating the substrate holder 104 and the substrate 106 deposited and held on the support 106.

[0221] According to a first option or manner, the substrate holder 104 and thus the substrate 106 are biased by a DC-bias source 126.sub.a. According to a second option (b) the substrate 106 and thus the substrate holder 104 is operated on electric ground potential. According to a further option (c) the substrate 106 is operated in an electrically floating manner. The substrate 104 is either held on the substrate support 106 in an electrically isolated manner or at least the directly supporting part of support 104 is operated in a floated manner, i.e. is electrically isolated from other parts of the sputtering chamber 100 which are on electric potentials.

[0222] According to option (d) the substrate holder 104 and thus the substrate 106 is biased by means of a RF-biasing source 126.sub.d.

[0223] In today's practiced embodiment which was already addressed above the substrate 106 is operated in an electrically floating manner or on ground potential.

[0224] In block 128 of FIG. 27 the options (a), (b), (c), (d) are addressed for electrically supplying those parts of the catcher plate arrangements 20.sub.5,7 which are of metal. According to option (a) these parts of the catcher plate arrangements may be electrically supplied by a DC supply source 128.sub.a. According to a second option (b) the addressed metal parts of the catcher plate arrangements 20.sub.5,7 are electrically supplied by an RF supply source 128.sub.b. According to option (c) the addressed parts are operated at ground potential and according to option (d) they are operated in an electrically floating manner.

[0225] Please note that if the one or both catcher plate arrangements comprise mutually isolated metal plates, and according to specific needs, such plates may electrically supplied differently as e.g. on different electric DC potentials. According to the today realized embodiment and as was addressed, each catcher plate arrangement 20.sub.5,7 is made of a metal plate and electrically operated on anode potential.

[0226] Making use of the sputtering source according to the invention it was possible to drastically reduce damage impacts on the manufactured, oxide coated substrates, the substrate the coating interface and the oxide coating.