Method and apparatus for vacuum deposition of highly ionized media in an electromagnetic controlled environment

• US 5,670,415 A
• Filed: 05/24/1994
• Issued: 09/23/1997
• Est. Priority Date: 05/24/1994
• Status: Expired due to Term

• Current Assignee: Depositech, Inc.
• Original Assignee: Depositech, Inc.
• Inventors: Rust, Ray Dean
• Primary Examiner(s): KUNEMUND, ROBERT M
• Application Number:
  US08/248,406
• Time in Patent Office: 1,218 Days
• Field of Search: 437/106, 204/192.32, 204/192.12
• US Class Current: 427/528
• CPC Class Codes: C23C 14/32 by explosion; by evaporation and subsequent ionisation of the vapours , e.g. ion-platingC23C14/34 - C23C14/48 take precedence
• CPC Class Codes: C23C 14/56 Apparatus specially adapted for continuous coating; Arrangements for maintaining the vacuum, e.g. vacuum locks
• CPC Class Codes: H01J 37/32422 Arrangement for selecting ions or species in the plasma
• CPC Class Codes: H01J 37/3266 Magnetic control means
• CPC Class Codes: H01J 37/32706 Polarising the substrate
• CPC Class Codes: H01J 37/32733 Means for moving the material to be treated
• CPC Class Codes: H01J 37/32761 Continuous moving

Abstract

A method and apparatus for vacuum depositing a coating onto a substrate are provided. The method includes the steps of: introducing an evaporant into a magnetically defined deposition region of a vacuum process chamber, ionizing the evaporant to form a plasma; generating a "magnetic bottle" magnetic field configuration to define the deposition region and to confine the plasma to the deposition region, further increasing the percentage ionization of the plasma to form a highly ionized media; creating a static dc electric field that is generally perpendicular to the magnetic field in the deposition region and parallel to the plane of the substrate; and then moving the substrate through the highly ionized media with the plane of the substrate and its direction of motion generally parallel to the magnetic field lines. The method of the invention is particularly suited to deposition of any atomistic evaporant onto intermediate-sized substrates.

Claims

1. A method of vacuum depositing a coating on a substrate, comprising:

providing an evaporant in a vacuum process chamber;

ionizing the evaporant using an external power source to form a plasma within the process chamber;

generating a non-uniform magnetic field within the process chamber having the configuration of a "magnetic bottle" to contain the plasma; and

then

moving the substrate into a deposition volume of the "magnetic bottle" along a direction of motion generally parallel to a primary axis of the "magnetic bottle" within the deposition volume to deposit the coating on the substrate to a desired thickness.

2. The method as recited in claim 1 wherein said substrate has a face establishing a plane and wherein the ionized evaporant is subjected to a dc electric field, said electric field having field vectors oriented generally in a plane parallel to said plane of said substrate face, said field vectors being oriented generally perpendicular to magnetic field lines.

3. The method as recited in claim 1 and wherein the material is evaporated using a metallization source adapted to heat and vaporize a solid metal.

4. The method as recited in claim 1 and wherein the substrate is a generally rectangular-shaped panel having front and rear faces oriented generally parallel to the primary axis of the "magnetic bottle" and both faces are simultaneously coated.

5. The method as recited in claim 1 and wherein the substrate is moved through the plasma by an electrically biasable carrier.

6. A method for vacuum depositing a coating on a substrate comprising:

vaporizing a deposition species in a vacuum process chamber to form an evaporant;

forming a plasma by ionizing the evaporant using an external power source with electrodes located within the process chamber;

generating a non-uniform magnetic field throughout the process chamber which contains the plasma and acts as a barrier to high energy electrons in the plasma striking the substrate said magnetic field having a primary axis;

subjecting the ionized evaporant to a dc electric field with field vectors oriented generally perpendicular to the primary axis of the magnetic field and parallel to a face of the substrate; and

then

moving the substrate through the plasma along a direction of motion generally parallel to the primary axis of the magnetic field to deposit the coating on the substrate to a desired thickness.

7. The method a recited in claim 6 and wherein the external power supply for the ionizing electrodes is a radio frequency source.

8. The method a recited in claim 6 and wherein the magnetic field is applied by a magnet surrounding the process chamber.

9. The method as recited in claim 6 and wherein the substrate is a generally rectangular-shaped panel having parallel faces oriented generally parallel to magnetic field lines as the substrate is moved through the plasma.

10. The method as recited in claim 9 and wherein the substrate is a dielectric and the deposition species is a metal.

11. The method as recited in claim 6 and wherein the substrate is conductive and is coupled to an external bias source.

12. The method as recited in claim 6 and wherein the deposition species is a metal vaporized using a metallization source.

13. The method as recited in claim 9 wherein the substrate is selected from the group consisting of a metal, a dielectric and a dielectric partially covered with metal and the deposition species is a dielectric.

14. The method as recited in claim 13 and wherein the substrate is intermediate-sized panel from about 100 mm to about 1400 mm on a side.

15. A method of vacuum deposition for plating a substrate having an exposed face with a metal, comprising:

evaporating the metal in a vacuum process chamber to form an evaporant;

ionizing the evaporant to form a plasma using electrodes mounted within the process chamber coupled to a rf power source;

generating magnetic field lines in the process chamber to provide a barrier to high energy electrons in the plasma striking the substrate;

subjecting the ionized evaporant to a dc electric field having electric field vectors oriented generally perpendicular to the magnetic field lines in a deposition volume; and

then

moving the substrate through the deposition volume on an electrically biasable carrier with a face of the substrate held by the carrier generally parallel to the magnetic field lines to deposit the metal onto the face.

16. The method as recited in claim 15 and wherein the metal is evaporated using a metallization source placed below the substrate carrier.

17. The method as recited in claim 15 and wherein the magnetic field lines are generated by magnetic field coils placed around the process chamber.

18. The method as recited in claim 15 and wherein the magnetic field lines are generated by permanent magnets placed around the process chamber.

19. The method as recited in claim 15 and wherein planes formed by a surface of the electrodes are generally parallel to one another and to a face of the substrate.

20. The method as recited in claim 15 and wherein the electrodes extend above and below the substrate.

21. The method as recited in claim 15 and wherein the electrodes are water cooled.