Geometries and configurations for magnetron sputtering apparatus

• US 5,618,388 A
• Filed: 10/04/1994
• Issued: 04/08/1997
• Est. Priority Date: 02/08/1988
• Status: Expired due to Fees

• Current Assignee: JDS Uniphase Corporation (Lumentum Holdings Inc.)
• Original Assignee: Optical Coating Laboratory, Inc. (Lumentum Holdings Inc.)
• Inventors: Seddon, Richard I., Dickey, Eric R., Scobey, Michael A., Allen, Thomas H., Soberanis, David L., Hichwa, Bryant P., Seeser, James W., Illsley, Rolf F., Van Horn, Craig C., Wentworth, Patrick R., Klinger, Robert F., Temple, Michael D., LeFebvre, Paul M.
• Primary Examiner(s): NGUYEN, NAM X
• Application Number:
  US08/317,781
• Time in Patent Office: 917 Days
• Field of Search: 204/192.12, 204/192.26, 204/298.16, 204/298.19, 204/298.2, 204/298.21, 204/298.22, 204/298.23, 204/298.24, 204/298.28, 118/719, 118/723 R, 118/730, 427/539, 427/535, 427/533, 427/551, 427/553, 427/537
• US Class Current: 204/192.12
• CPC Class Codes: C23C 14/0047 Activation or excitation of reactive gases outside the coating chamber
• CPC Class Codes: C23C 14/0078 by moving the substrates between spatially separate sputtering and reaction stations
• CPC Class Codes: C23C 14/083 of refractory metals or yttrium
• CPC Class Codes: C23C 14/10 Glass or silica
• CPC Class Codes: C23C 14/3407 Cathode assembly for sputtering apparatus, e.g. Target
• CPC Class Codes: C23C 14/352 using more than one target C23C14/56 takes precedence
• CPC Class Codes: C23C 14/505 for rotation of the substrates
• CPC Class Codes: C23C 14/56 Apparatus specially adapted for continuous coating; Arrangements for maintaining the vacuum, e.g. vacuum locks
• CPC Class Codes: C23C 14/562 for coating elongated substrates
• CPC Class Codes: C23C 14/568 Transferring the substrates through a series of coating stations C23C14/562 takes precedence
• CPC Class Codes: C23C 14/58 After-treatment
• CPC Class Codes: C23C 8/02 Pretreatment of the material to be coated C23C8/04 takes precedence

Abstract

A thin film coating system incorporates separate, separately-controlled deposition and reaction zones for depositing materials such as refractory metals and forming oxides and other compounds and alloys of such materials. The associated process involves rotating or translating workpieces past the differentially pumped, atmospherically separated, sequentially or simultaneously operated deposition and reaction zones and is characterized by the ability to form a wide range of materials, by high throughput, and by controlled coating thickness, including both constant and selectively varied thickness profiles.

Claims

1. A coating system, comprising:

a vacuum chamber;

carrier means mounted within the vacuum chamber and adapted for mounting substrates thereon;

coating means comprising at least a first device in the form of a deposition device positioned adjacent the carrier means and adapted for depositing a selected material onto the substrates and at least a second device in the form of an ion source device positioned adjacent the carrier means and adapted for providing a locally intensified plasma between the ion source device and the carrier means for effecting a selected chemical reaction with the selected material;

the deposition device and the ion source device spatially separated such that each acts on a different portion of the carrier means;

at least one of the carrier means and the coating means being adapted for movement relative to the other of the carrier means and the coating means along a selected path; and

the combination of carrier means configuration, deposition device configuration and said relative movement being selected to provide controlled thickness profiles for deposited material.

2. The coating system of claim 1, wherein the carrier means is a rotatable drum or cylinder mounting the substrates thereon for moving the substrates past the deposition device and the ion source device.

3. The coating system of claim 2, wherein the substrate carrier means is translatable along the axis of rotation and, in combination with the rotation, provides a spiral path of movement.

4. The coating system of claim 1, wherein the carrier mounting means comprises a pair of concentric rotatable drums which are translatable along said rotation axis to position the drums at first and second spaced positions proximate to work stations associated with said positions.

5. The coating system of claim 1, wherein the substrate carrier means comprises a rotatable drum having an enclosed atmospheric pressure drum therein mounting said devices.

6. The coating system of claim 1, wherein the substrate carrier mounting means comprises a rotatable drum having mounted about the circumference thereof a plurality of faceted substrate carriers, each said carrier being mounted for rotation along an axis generally parallel to the rotational axis of the drum for selectively presenting the facets to said devices.

7. The coating system of claim 1, the carrier means including a spider assembly comprising at least a pair of spaced arms mounting substrate-carrying cylinders between opposite ends thereof;

the coating system further comprising means mounting the spider assembly for rotation about an axis and past the adjacent coating means; and

means mounting the cylinders for individual rotation about associated axes generally parallel to said axis.

8. The coating system of claim 1, wherein the carrier means is a movable web or belt-type carrier.

9. The coating system of claim 1, wherein the substrate mounting means comprises:

a drum;

feed and take-up wind roll means internal to said drum and adapted for traversing a flexible web through an opening in the drum and about the external circumference of the drum continuously or intermittently; and

means controlling frictional engagement between the web and the drum to selectively permit traversal of the web relative to the drum.

10. The coating system of claim 9, wherein the control means comprises fingers spanning the peripheral edges of the drum and mounting the web thereon and actuable at said opening for releasing and re-engaging the feed and take-up wind means.

11. The coating system of claim 9, wherein the control means comprises rollers mounted about the periphery of a drum with their axes of rotation generally aligned with the axis of rotation of the drum.

12. The coating system of claim 1, further comprising a deposition device in the form of a rotatable cylinder comprising at least a plurality of peripherally positioned linear magnetron-enhanced deposition devices.

13. The coating system of claim 12, wherein the carrier means is substantially flat and adapted for translational movement.

14. The coating system of claim 1, wherein:

said path is circular and the carrier means is substantially flat and is adapted for movement along said path; and

the carrier means further comprising means mounting the substrates thereto for movement transverse to said path.

15. The apparatus of claim 1 wherein the carrier means is substantially flat.

16. A process for forming films on a substrate comprising:

providing within a vacuum chamber a carrier means having a rotation axis, the carrier means comprising a spider assembly including at least a pair of spaced arms mounting substrate carrying cylinders between opposite ends thereof, the spider assembly being rotatable about the carrier means rotation axis and the cylinders being individually rotatable about associated axes generally parallel to the carrier means rotation axis;

providing film deposition devices and ion source plasma generation devices at selected positions about the periphery of the carrier means, the deposition devices and the ion source plasma generation devices arranged such that at least one deposition device and one ion source plasma generation device may be located spatially separated adjacent each cylinder such that each thereof acts on a different portion of the cylinder; and

selectively indexing the spider assembly between the selected positions and rotating the cylinders while at the selected positions for selectively depositing at least one predetermined material onto the substrate and effecting a selected chemical reaction with the deposited material at each position as the substrate passes the ion source plasma generation device;

the combination of carrier configuration, deposition device configuration and the rotation providing controlled thickness profiles of material deposited on similarly-shaped substrate surfaces.

17. A process for coating a substrate in a vacuum chamber, comprising:

mounting the substrate on a carrier;

moving the carrier and the mounted substrates past at least a first device in the form of a deposition device positioned adjacent the carrier for depositing a selected material onto the substrate and past a second device for providing a locally intensified plasma between the second device and the carrier to effect a selected chemical reaction with the selected material as the substrate passes the second device; and

, during movement of the carrier, simultaneously moving the carrier and the coating means relative to one another along a selected path to provide the same controlled thickness profiles for material deposited on substrates which are similarly-shaped, one to the other, and mounted at different locations on the carrier.

18. Apparatus for depositing an optical coating on a substrate in a vacuum chamber, comprising:

a substrate holder located in said vacuum chamber, said substrate holder being rotatable about an axis generally transverse thereto and including means for supporting the substrate thereon;

at least first and second deposition devices located in the vacuum chamber, for depositing respectively first and second metals;

at least one reactive ion source device located in said vacuum chamber for providing a locally intensified plasma in and of at least one reactive gas between the ion source device and the substrate holder to chemically react with the deposited layer of material; and

said deposition devices and said ion source device being located adjacent said substrate holder and spatially separated from each other such that each acts over a separate region of the substrate holder, and said substrate holder, said deposition devices, and said reactive ion source device being arranged such that, when said substrate holder is rotated, the substrates move sequentially past said first and second deposition devices and said reactive ion source device, for depositing a layer of material selected from the first metal and the second metal and completely chemically reacting said layer with the reactive plasma as the substrate passes the ion source device.

19. The apparatus of claim 18, further comprising:

means for activating at least one of said first and second deposition devices and for activating said reactive ion source device such that, when said substrate holder is rotated, a metal layer is deposited on the substrate by said at least one of said first and second deposition devices and the deposited layer is completely converted to a compound of the metal and the reactive gas by said reactive ion source device, whereby when rotation of said substrate holder is continued with simultaneous operation of the at least one of said first and second deposition devices and said reactive ion source device, sequential deposition and reaction of thin metal layers builds up a coating of the compound on the substrate.

20. The apparatus of claim 19, wherein said activating means is adapted for simultaneously activating said first and second deposition devices and said reactive ion source device to build up a ternary layer of a compound including the first and second metals.

21. The apparatus of claim 19, wherein said activating means is adapted for alternately activating said first deposition device and said second deposition device, for forming alternating layers of compounds of the first metal and the second metal.

22. The apparatus of claim 21 wherein said first and second deposition devices are selected from the group consisting of stationary magnetron sources, rotating magnetron sources, point source sputter guns, stationary evaporation sources, centrifugal force rotating evaporation sources, and reactive ion plating sources, and said reactive ion source device is selected from the group consisting of self-starting ion guns, point ion sources, microwave sources, unbalanced magnetron sources, RF sources, and arc sources.

23. The apparatus of claim 22 wherein said first and second deposition devices are stationary magnetron sources and said reactive ion source device is an unbalanced magnetron source, and said first and second stationary magnetron sources are activated in a low reactive gas partial pressure for sputtering in a metal mode and said unbalanced magnetron source is activated in a high reactive gas partial pressure for creating said locally intensified reactive plasma.

24. Apparatus for depositing a multilayer optical interference coating on a substrate, comprising:

a vacuum chamber;

vacuum pump means, connected to said vacuum chamber for creating a vacuum therein;

a substrate holder located in said vacuum chamber, said substrate holder being rotatable about an axis generally normal thereto and including means for supporting the substrate thereon;

at least first and second magnetron sources located in said vacuum chamber, for depositing respectively first and second metals;

means for operating the first and second magnetron sources for selectively depositing the first and second metals;

at least one magnetron enhanced ion source device located in said vacuum chamber for providing locally intensified plasma including a reactive gas between said magnetron enhanced ion source device and said substrate holder; and

said first and second magnetron sources and said magnetron enhanced ion source device being located adjacent said substrate holder and spatially separated from each other such that each acts over a separate region of the substrate holder, and said substrate holder, said first and second magnetron sources, and said magnetron enhanced ion source device being arranged such that, when said substrate holder is rotated, the substrate is moved sequentially past said first and second magnetron sources and said magnetron enhanced ion source device for depositing a layer of metal and completely and chemically reacting the layer during a single pass of the substrate past the magnetron enhanced ion source device.

25. The apparatus of claim 24 wherein said first and second magnetron sources are adapted for effecting a low reactive gas partial pressure for sputtering in a metal mode, and said magnetron enhanced ion source device is an unbalanced magnetron source adapted for effecting a high reactive gas partial pressure for creating the locally intensified reactive plasma.

26. Apparatus for depositing a multilayer optical interference coating on a substrate, comprising:

a vacuum chamber;

vacuum pump means, connected to said vacuum chamber for creating a vacuum therein;

a substrate holder located in said vacuum chamber, said substrate holder being rotatable about an axis generally normal thereto and including means for supporting the substrate thereon;

at least one magnetron source located in said vacuum chamber, for depositing a metal on the substrate;

at least one magnetron enhanced ion source device located in said vacuum chamber for providing a locally intensified plasma including a reactive gas between said magnetron enhanced ion source device and said substrate holder; and

said magnetron source and said magnetron enhanced ion source device located adjacent said substrate holder and spatially separated such that each acts over a different region of said substrate holder, and said substrate holder, said magnetron source, and said magnetron enhanced ion source device being arranged such that, when said substrate holder is rotated, the substrate is moved sequentially past said magnetron source and said magnetron enhanced ion source device for depositing a metal layer on the substrate and completely reacting the metal layer as the substrate passes said magnetron enhanced ion source device, whereby the metal layer is converted to a compound of the reactive gas.

27. The apparatus of claim 26 wherein said magnetron source is activated in a low reactive gas partial pressure for sputtering in a metal deposition mode, and said magnetron enhanced ion source is an unbalanced magnetron source activated in a high reactive gas partial pressure for creating said locally intensified reactive plasma.

28. The apparatus of claim 27 wherein the substrate holder is substantially flat.

29. The apparatus of claim 27 wherein the substrate holder is substantially disk shaped.

30. The apparatus of claim 26 wherein the substrate holder is substantially flat.

31. The apparatus of claim 26 wherein the substrate holder is substantially disk shaped.

32. A method of forming a layer of a metal compound on a substrate, comprising:

supporting the substrate on a substrate holder;

providing a magnetron enhanced sputter deposition source for depositing a metal and a plasma generation device for forming a locally intensified plasma including a reactive gas between said plasma generation device and the substrate, said magnetron enhanced sputter deposition source and said plasma generation device located adjacent the substrate holder and spatially separated such that each acts over a different region of the substrate holder;

rotating the substrate holder past said magnetron enhanced sputter deposition source for forming at least one monolayer of the metal on the substrate, and through the locally intensified plasma, for sequentially depositing said at least one monolayer of metal on the substrate and completely chemically reacting said monolayer of metal with the reactive gas in the locally intensified plasma before the substrate holder returns to the magnetron-enhanced sputter deposition device, to form a compound of the metal and the reactive gas; and

continuing the substrate holder rotation until a layer of the metal compound of a predetermined thickness is built up on the substrates.

33. The method of claim 32, further comprising activating said magnetron enhanced sputter deposition source in a low reactive gas partial pressure for sputtering in a metal deposition mode, and activating said plasma generation device in a high reactive gas partial pressure for creating said locally intensified reactive plasma.

34. A method of forming a layer of a metal compound on a substrate, comprising the steps of:

(a) providing a vacuum chamber including a substrate holder rotatable about an axis transverse thereto, at least one magnetron enhanced deposition source for depositing a metal, and at least one magnetron enhanced ion source device for creating a locally intensified plasma including a reactive gas between the magnetron enhanced ion source and the substrate holder, said magnetron enhanced deposition source and said magnetron enhanced ion source device located adjacent the substrate holder and spatially separated such that each acts on a different region of the substrate holder;

(b) supporting the substrate on said substrate holder, with the substrate, said magnetron enhanced deposition source, and said magnetron enhanced ion source arranged such that, when said substrate holder is rotated, the substrate is moved sequentially past said magnetron enhanced deposition source and said magnetron enhanced ion source device;

(c) activating said magnetron enhanced deposition source and said magnetron enhanced ion source device;

(d) rotating said substrate holder such that the substrate moves sequentially past said activated magnetron enhanced deposition source and said activated magnetron enhanced ion source device, thereby sequentially depositing at least one monolayer of metal on the substrate and reacting said at least one monolayer of metal with the reactive gas to form a compound of the metal and reactive gas as the substrate passes through the locally intensified plasma before the substrate is returned to the region of the magnetron-enhanced deposition source; and

(e) continuing the substrate holder rotation until a layer of the metal compound of a predetermined thickness is built up on the substrate.

35. The method of claim 34 wherein said magnetron enhanced deposition source is adapted for effecting a low reactive gas partial pressure for sputtering in a metal deposition mode, and said magnetron enhanced ion source device is an unbalanced magnetron source and is adapted for effecting a high reactive gas partial pressure for creating said locally intensified reactive plasma.

36. The method of claim 35 wherein the substrate holder is substantially flat.

37. The method of claim 35 wherein the substrate holder is substantially disk shaped.

38. The method of claim 34 wherein the substrate holder is substantially flat.

39. The method of claim 34 wherein the substrate holder is substantially disk shaped.

40. Apparatus for depositing a multi-layer optical coating on a plurality of substrates, comprising:

a vacuum chamber;

a substrate holder located in the vacuum chamber, the substrate holder being mounted for rotation about an axis in the vacuum chamber, including a means for receiving, holding and transporting substrates at the surface of the substrate holder;

means adapted for rotating the substrate holder at a selected velocity about the axis past physically spaced work stations, the physically spaced work stations comprising at least two first work stations and at least one second work station, the physically spaced first and second work stations positioned adjacent to the substrate holder in different regions of the vacuum chamber;

at least two magnetron sputter devices positioned at the first work stations adjacent to the substrate holder, each sputter device having a target of selected material for sputter deposition on substrates and wherein the magnetron sputter devices are operated either alternately or simultaneously;

means for selecting the process operating conditions of the magnetron sputter devices for sputter depositing material from a selected sputter device onto substrates being transported by the substrate holder;

at least one magnetron enhanced ion source device positioned at the second work station adjacent to the substrate holder, and including means for providing an oxygen plasma for oxidation of sputter deposited materials;

means for selecting the process operating conditions of the magnetron enhanced ion source device for effecting a desired reaction with the thin layer of sputter deposited material on the substrates; and

the substrate holder, the sputter devices, the ions and the ion source device arranged so that, when the substrate holder is rotated at a selected velocity and a selected sputter device is operated, the substrate traverses repeatedly past the sputter devices and the ion source device, depositing the thin layer of material from the selected sputter device onto the substrates during each one of the repeated passes and completely reacting each the thin layer of material in the oxygen plasma at the second work station during each pass of the substrate holder.

41. A process for depositing a multi-layer optical coating on a plurality of substrates, comprising the steps:

(A) continuously rotating a planar array of substrates about an axis perpendicular to the array, repeatedly traversing the array past at least a pair of first stations and a second station;

at one of the first stations, sputter coating on the rotating substrates a relatively thin layer of a first metal during a pass of the substrates past the one first station;

at the second station, completely oxidizing the relatively thin layer of the first metal on the rotating substrates in an oxygen plasma during said pass of the substrates past the second station; and

continuing the deposition and oxidation of the relatively thin layers of the first metal to form a relatively thick first oxide layer of predetermined thickness;

(B) continuously rotating the planar array of substrates about the axis perpendicular to the array, repeatedly traversing the array past the pair of first stations and the second station;

at the second of the first stations, sputter coating on the rotating substrates a relatively thin layer of a second metal during a pass of the substrates past the second first station;

at the second station, completely oxidizing the relatively thin layer of the second metal on the rotating substrates in an oxygen plasma during said pass of the substrates past the second station; and

continuing the deposition and oxidation of the relatively thin layers of the second metal to form a relatively thick second oxide layer of predetermined thickness; and

(C) selectively repeating step (A) and step (B) to form a multi-layer optical coating.

42. The process of claim 41, wherein continuous rotation of the array of substrates about the axis is continued between the steps.