Nanoantenna scanning probe tip, and fabrication methods

Patent metadata

Field	Value
Publication number	US-10012674-B2
Application number	US-201615257150-A
Country	US
Kind code	B2
Filing date	Sep 6, 2016
Priority date	Sep 4, 2015
Publication date	Jul 3, 2018
Grant date	Jul 3, 2018

Abstract

The invention provides a nanoantenna scanning probe tip for microscropy or spectroscopy. The nanoantenna scanning probe tip includes a sharp probe tip covered with a contiguous film of predetermined sized and shaped plasmonic nanoparticles. A method for forming the nanoantenna scanning probe tip by trapping nanoparticles having a predetermined size and shape at a liquid surface using surface tension, forming a uniform and organized monolayer film on the liquid surface, and then transferring portions of the film to a sharp probe tip. In preferred embodiments, the sharp probe tip is one of a conductive STM (scanning tunneling microscopy) tip, a tuning fork tip or an AFM (atomic force microscopy) tip. The sharp tip can be blunted with an oxide layer.

First claim

The invention claimed is:

1. A method for fabricating a nanoantenna scanning probe, comprising:
placing a sharp probe tip in liquid under a liquid surface;
trapping nanoparticles having a predetermined size and shape on the liquid surface using surface tension;
forming a uniform and organized monolayer film on the liquid surface; and
transferring portions of the organized monolayer film to the sharp probe tip to coat the sharp probe tip with a monolayer of the nanoparticles by moving the sharp prove tip through the organized monolayer film on the liquid surface.

2. The method of claim 1 , wherein the sharp probe tip comprises a conductive STM (scanning tunneling microscopy) tip.

3. The method of claim 1 , wherein the sharp probe tip comprises a tuning fork tip.

4. The method of claim 1 , wherein the sharp probe tip comprises an AFM (atomic force microscopy) tip.

5. The method of claim 1 , wherein the sharp probe tip comprises a blunted tip.

6. The method of claim 5 , wherein the sharp probe tip blunted with an oxide or nitride layer.

7. The method of claim 6 , wherein sharp probe tip comprises a blunted AFM tip.

8. The method of claim 6 , comprising a step of plasma enhanced chemical vapor deposition to form the oxide layer.

9. The method of claim 8 , wherein the oxide blunts the tip to a radius of curvature such that the size of the nanoparticles to the radius of curvature is ˜1:1.

10. The method of claim 1 , comprising transferring portions of the film to a plurality of sharp probe tips.

11. The method of claim 1 , wherein the nanoparticles comprise silver nanocubes.

12. The method of claim 1 , wherein the nanoparticles comprise gold bipyramidal nanoparticles.

13. The method of claim 1 , wherein the AFM tip comprises silicon blunted with a silicon dioxide coating.

14. The method of claim 1 , wherein said forming comprises compressing the nanoparticle film.

15. The method of claim 14 , wherein said transferring comprises bringing the sharp probe tip into contact with the nanoparticle film via a mechanical mover.

16. The method of claim 14 , wherein the mechanical mover brings the apex of the sharp probe tip first into contact with the nanoparticle film.

17. A nanoantenna scanning probe tip for microscropy or spectroscopy comprising sharp probe tip covered with a contiguous monolayer film of predetermined sized and shaped plasmonic nano particles, wherein the sharp prove tip comprises a blunted AFM tip, conductive STM tip or tuning fork tip, having a radius of curvature that equals or exceeds a seize of the plasmonic nano particles.

18. The nanoantenna scanning probe tip of claim 17 , wherein the AFM tip is blunted with an oxide or nitride coating.

19. The nanoantenna scanning probe tip of claim 17 , further comprising a protective coating over the plasmonic nano particles.

20. The nanoantenna scanning probe tip of claim 17 , wherein the nanoparticles comprise silver nanocubes.

21. The nanoantenna scanning probe tip of claim 17 , wherein the nanoparticles comprise gold bipyramidal nanoparticles.

22. The nanoantenna scanning probe tip, of claim 17 , wherein the sharp probe tip comprises a silicon AFM (atomic force microscopy) tip blunted with a silicon dioxide coating.

23. The nanoantenna scanning probe tip of claim 17 , wherein the sharp probe tip comprises a conductive STM (scanning tunneling microscopy) tip.

24. The nanoantenna scanning probe tip of claim 17 , wherein the sharp probe tip comprises a tuning fork tip.

25. A method for scanning probe spectroscopy, the method comprising:
bringing a nanoantenna scanning probe into contact or near a surface, wherein the nanoantenna scanning probe comprises a sharp probe tip coated with a monolayer film of plasmonic nanoparticles, wherein the sharp probe tip comprises a blunted AFM tip, conductive STM tip or tuning fork tip, having a radius of curvature that equals or exceeds a size of the plasmonic nano particles;
moving the probe relative to the surface;
directing a radiation beam at the probe during said moving; and
obtaining spectra from the probe during said moving.

26. The method of claim 25 , wherein the nanoparticles comprise silver nanocubes.

27. The method of claim 25 , wherein the nanoparticles comprise gold bipyramidal nanoparticles.

28. The method of claim 25 , wherein the radiation beam comprises a 488-1064 nm laser beam.

29. The method of claim 28 , wherein the radiation beam comprises a ˜700 nm to ˜850 nm nm laser beam.

Assignees

• Univ California

Inventors

• Dill Tyler Jamison
• Tao Andrea Rae

Classifications

• G01Q60/38

  Probes, their manufacture, or their related instrumentation, e.g. holders · CPC title

• G01Q30/025 Primary

  Optical microscopes coupled with SPM · CPC title

• G01Q60/16

  Probes, their manufacture, or their related instrumentation, e.g. holders · CPC title

• G01Q30/02 Primary

  Non-SPM analysing devices, e.g. SEM [Scanning Electron Microscope], spectrometer or optical microscope · CPC title

• G01Q60/06

  SNOM [Scanning Near-field Optical Microscopy] combined with AFM [Atomic Force Microscopy] · CPC title