Method and apparatus for smoothing surfaces on an atomic scale

• US 20050003672A1
• Filed: 08/09/2004
• Published: 01/06/2005
• Est. Priority Date: 05/31/2002
• Status: Abandoned Application

• Current Assignee: Adrian J. Devasahayam, Jacques C.S. Kools
• Original Assignee: Adrian J. Devasahayam, Jacques C.S. Kools
• Inventors: Devasahayam, Adrian J., Kools, Jacques C.S.
• Application Number:
  US10/915,583
• Publication Number:
  US 20050003672A1
• Time in Patent Office: Days
• US Class Current: 438/698
• CPC Class Codes: C23C 14/022 by means of bombardment with energetic particles or radiation
• CPC Class Codes: C23C 14/5833 Ion beam bombardment
• CPC Class Codes: C23F 4/00 Processes for removing metallic material from surfaces, not provided for in group C23F1/00 or C23F3/00
• CPC Class Codes: H01F 41/302 for applying spin-exchange-coupled multilayers, e.g. nanostructured superlattices spin-exchange-coupled multilayers H01F10/32
• CPC Class Codes: H01J 37/32357 Generation remote from the workpiece, e.g. down-stream
• CPC Class Codes: H01L 21/32115 Planarisation

Abstract

A method and an apparatus for smoothing surfaces on an atomic scale. The invention performs smoothing of surfaces by use of a low energy ion or neutral noble gas beam, which may be formed in an ion source or a remote plasma source. The smoothing process may comprise a post-deposition atomic smoothing step (e.g., an assist smoothing step) in a multilayer fabrication procedure. The invention utilizes combinations of relatively low particle energy (e.g., below the sputter threshold of the material) and near normal incidence angles, which achieve improved smoothing of a surface on an atomic scale with substantially no etching of the surface.

Claims

1. An apparatus for smoothing a surface of a material on an atomic scale, the apparatus comprising:

a chamber in which the material is disposed; and

a source which is disposed in the chamber and which provides a beam of particles which impact the surface with a relatively low energy, effective to cause smoothing of the surface with substantially no etching of the surface.

2. The apparatus of claim 1 wherein the relatively low energy is below a sputter threshold of the material.

3. The apparatus of claim 2 wherein the relatively low energy is in the range of 20 eV to 40 eV.

4. The apparatus of claim 1 wherein the source provides a beam of ionized particles.

5. The apparatus of claim 4 wherein the ionized particles are noble gas molecules.

6. The apparatus of claim 1 wherein the source provides a beam of neutral particles.

7. The apparatus of claim 1 wherein the beam of particles impacts the surface at an angle relatively close to a normal angle of incidence.

8. The apparatus of claim 7 wherein the angle of impact is in the range of 0 to 30 degrees off normal.

9. The apparatus of claim 1 further comprising:

a stage which is disposed in the chamber and which is adapted to hold the material.

10. The apparatus of claim 9 wherein the stage is selectively tiltable, effective to alter the angle that the beam of particles impacts the surface of the material.

11. The apparatus of claim 1 further comprising:

at least one deposition chamber for depositing a layer of material on the surface; and

a movable device for transporting the material between the chamber and the at least one deposition chamber.

12. The apparatus of claim 1 wherein the chamber is a multi-target chamber, including a first portion containing the source, and at least one second portion for depositing a film on the material.

13. The apparatus of claim 12 further comprising a movable arm for transporting the material between the first and at least one second portion of the chamber.

14. A method for smoothing a surface of a material on an atomic scale comprising the step of:

exposing the surface to a beam of particles having a relatively low energy, effective to smooth the surface without etching the surface.

15. The method of claim 14 wherein the relatively low energy is below the sputter threshold of the material.

16. The method of claim 15 wherein the relatively low energy is in the range of 20 eV to 40 eV.

17. The method of claim 15 further comprising the step of causing the beam of particles to impact the surface at an angle relatively close to a normal angle of incidence.

18. The method of claim 17 wherein the angle of impact is in the range of 0 to 30 degrees off normal.

19. The method of claim 18 wherein the particles comprise ionized noble gas particles.

20. The method of claim 19 wherein the particles comprise neutral particles.

21. The method of claim 14 wherein the surface comprises a metal surface.

22. The method of claim 14 wherein the surface comprises a non-metal crystalline surface.

23. The method of claim 14 wherein the step of exposing the surface to a beam of particles having a relatively low energy, effective to smooth the surface without etching the surface, is performed as part of a nanotechnology fabrication process.

24. A method for forming a metallic multilayer material, comprising the steps of:

forming a first layer of material having a surface;

generating a beam of particles having an energy below a sputter threshold of the material;

causing the beam of particles to impact the surface at an angle relatively close to a normal angle of incidence, effective to smooth the surface without etching the surface; and

depositing a second layer of material on the smoothed surface.

25. The method of claim 24 wherein the first layer of material comprises copper.

26. The method of claim 25 wherein the beam of particles comprises ionized noble gas particles.

27. The method of claim 26 wherein the ionized noble gas particles are selected from the group consisting of Xe, Ar, Kr and Ne particles.

28. The method of claim 26 wherein the energy is in the range of 20 eV to 40 eV.

29. The method of claim 28 wherein the angle of impact is in the range of 0 to 30 off normal.