Morphology and Spectroscopy of Nanoscale Regions using X-Rays Generated by Laser Produced Plasma

• US 20050211910A1
• Filed: 03/29/2005
• Published: 09/29/2005
• Est. Priority Date: 03/29/2004
• Status: Abandoned Application

• Current Assignee: JMAR LLC
• Original Assignee: JMAR Research Inc. (JMAR Technologies, Inc.)
• Inventors: Rieger, Harry, Bloom, Scott H.
• Application Number:
  US10/907,321
• Publication Number:
  US 20050211910A1
• Time in Patent Office: Days
• US Class Current: 378/44
• CPC Class Codes: C23C 16/18 from metallo-organic compounds
• CPC Class Codes: C23C 16/484 using X-ray radiation
• CPC Class Codes: G01N 2223/076 X-ray fluorescence
• CPC Class Codes: G01N 23/207 Diffractometry using detectors, e.g. using a probe in a central position and one or more displaceable detectors in circumferential positions
• CPC Class Codes: G01N 23/223 by irradiating the sample with X-rays or gamma-rays and by measuring X-ray fluorescence
• CPC Class Codes: G01N 23/227 Measuring photoelectric effect, e.g. photoelectron emission microscopy [PEEM]
• CPC Class Codes: H05G 2/001 Production of X-ray radiation generated from plasma

Abstract

A system and method is disclosed for generation of a nanoplasma and/or nanofluorescence. The system includes an emissions source of soft x-rays. The emissions source can include a laser system as an energy source and target material that acts as a radiation source when illuminated by the laser system. The system further includes focusing optics particularly suited for manipulation of wavelengths associated with x-rays. The focusing optics can focus the x-rays onto a desired target so that a nanoplasma or nanofluorescent spot can be formed to have a diameter of less than 200 nm. Radiation from the nanoplasma or nanofluorescent spot can be examined, for example using a spectrometer, in order to perform a highly-selective material analysis of the desired target. Other applications include using the nanoplasma for nanoablation and/or nanodeposition processes.

Claims

1. A nanoplasma-generating device, comprising:

an emissions source that includes a short-pulse laser system and a radiation source, the laser system operable to generate a laser pulse having an energy density sufficient to form a point plasma at the radiation source that emits short-wavelength radiation; and

a focusing optic for receiving the short-wavelength radiation from the radiation source and focusing the radiation onto a target to form a nanoplasma.

2. A device according to claim 1, wherein said short-wavelength radiation has a wavelength in a range of 0.5 nm to 15 nm.

3. A device according to claim 1, wherein said focusing optic includes at least one Bragg multilayer coating.

4. A device according to claim 1, wherein said focusing optic includes at least one of a grazing incidence optical element and a diffractive optical element.

5. A device according to claim 1, wherein said focusing optic is for focusing the radiation onto the target such that the nanoplasma has a diameter of less than 200 nm.

6. A device according to claim 1, further comprising a positioning stage for positioning the target.

7. A device according to claim 1, wherein the laser pulse generated by the short-pulse laser system has a pulse width of less than one nanosecond and an energy of at least 200 mJ.

8. A device according to claim 7, wherein the radiation source comprises a metallic tape.

9. A device according to claim 8, wherein the focusing optic comprises a first relay condenser, an intermediate aperture, and a second relay condenser, wherein the first relay condenser is operable to receive the short-wavelength radiation from the radiation source and focus the radiation onto the intermediate aperture, and wherein the intermediate aperture permits the passage of the short-wavelength radiation to the second relay condenser, and wherein the second relay condenser is operable to receive the short-wavelength radiation from the intermediate aperture and focus the radiation onto the target.

10. A device according to claim 1, further comprising an analyzing assembly for performing a spectroscopic analysis of the target based on radiation emitted from the nanoplasma.

11. A device according to claim 1, wherein the nanoplasma causes ablation of material of the target.

12. A device according to claim 1, wherein a reactive gas is provided in the vicinity of the target, wherein the nanoplasma causes reaction of the reactive gas so that a resultant is produced and deposited on the target.

13. A method for generating a nanoplasma comprising:

providing a laser pulse having an energy density sufficient to form a point plasma at a radiation source so as to generate short-wavelength radiation;

generating a nanoplasma by focusing the short-wavelength radiation onto a spot on a target.

14. A method according to claim 13, wherein said short-wavelength radiation has a wavelength in a range of 0.5 nm to 15 nm.

15. A method according to claim 13, wherein step of focusing is performed at least in part by an optical element having a Bragg multilayer coating.

16. A method according to claim 13, wherein said step of focusing is performed at least in part by at least one of a grazing incidence optical element and a diffractive optical element.

17. A method according to claim 13, wherein the nanoplasma has a diameter of less than 200 nm.

18. A method according to claim 13, further comprising a step of controlling a positioning stage in order to position the target.

19. A method according to claim 13, wherein the laser pulse has a pulse width of less than one nanosecond and an energy of at least 200 mJ.

20. A method according to claim 19, wherein the radiation source comprises a metallic tape.

21. A method according to claim 20, wherein the focusing of the short-wavelength radiation comprises:

receiving short-wavelength radiation from the radiation source at a relay condenser and focusing the radiation onto an intermediate aperture;

permitting the passage of the short-wavelength radiation through the intermediate aperture to a second relay condenser; and

receiving the short-wavelength radiation at the second relay condenser and focusing the radiation onto the spot on the target.

22. A method according to claim 13, further comprising performing a spectroscopic analysis of the target based on radiation emitted from the nanoplasma.

23. A method according to claim 13, wherein the generating of the nanoplasma includes ablating an amount of material from the target.

24. A method according to claim 13, further comprising providing a reactive gas in the vicinity of the target, wherein the generating of the nanoplasma includes causing reaction of the reactive gas so that a resultant is produced and deposited on the target.

25. A nanofluorescence-generating device, comprising:

a short-pulse laser system operable to generate a laser pulse having an energy density sufficient to form a point plasma at a radiation source that emits short-wavelength radiation; and

a focusing optic operable to receive the short-wavelength radiation from the radiation source and focus the radiation onto a target so that a nanofluorescent spot is formed.

26. A device according to claim 25, wherein the laser pulse has a pulse width of less than one nanosecond and an energy of at least 200 mJ.

27. A device according to claim 26, wherein the radiation source comprises a metallic microtarget.

28. A device according to claim 27, wherein the focusing optic comprises:

a first parabolic reflector having a focal point substantially aligned with the radiation source, the first parabolic reflector comprising multilayer interference films operable to reflect and substantially collimate short-wavelength radiation emitted by the radiation source; and

a second parabolic reflector having a focal point substantially aligned with the target, the parabolic reflector comprising multilayer interference films operable to reflect and focus short-wavelength radiation onto a spot on the target having a diameter less than 200 nm so as to generate a nanofluorescent spot.

29. A device according to claim 25, further comprising an analyzing assembly for performing a spectroscopic analysis of the target based on radiation from the nanofluorescent spot.

30. A device according to claim 25, wherein the nanofluorescent spot has a diameter of less than 200 nm.

31. A method for generating a nanofluorescent spot comprising:

providing a laser pulse having an energy density sufficient to form a point plasma at a radiation source that emits short-wavelength radiation; and

generating a nanofluorescent spot by focusing the short-wavelength radiation onto a spot on a target.

32. A method according to claim 31, wherein the laser pulse has a pulse width of less than one nanosecond and an energy of at least 200 mJ.

33. A method according to claim 32, wherein the generating of the short-wavelength radiation source comprises a metallic microtarget.

34. A method according to claim 33, wherein the focusing of the radiation comprises:

reflecting and collimating the short-wavelength radiation emitted by the radiation source with a first parabolic reflector having a focal point substantially aligned with the radiation source, the first parabolic reflector comprising multilayer interference films; and

reflecting and focusing the short-wavelength radiation onto the spot on the target with a second parabolic reflector having a focal point substantially aligned with the target, the second parabolic reflector comprising multilayer interference films.

35. A method according to claim 31, further comprising performing a spectroscopic analysis of the target based on radiation from the nanofluorescent spot.

36. A method according to claim 31, wherein the nanofluorescent spot has a diameter of less than 200 nm.