Method of fabricating nanotips with controlled profile
AssigneesNational Research Council of Canada, The Governors of the University of Alberta
InventorsJason L. Pitters, Radovan Urban, Robert A. Wolkow
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Abstract
A nanotip, is fabricated by modifying a precursor nanotip having an apex and a shank by applying an electric field in the presence of a reactive gas to perform field-assisted etching wherein atoms are preferentially removed from the shank by chemical interaction with the reactive gas, and controlling the reactive gas pressure and/or tip voltage to vary the electric field so as to promote field evaporation of apex atoms during fabrication of the nanotip and thereby control the overall profile of the resulting nano-tip. The method permits shaping of the overall tip profile.
Claims25
A method of fabricating a nanotip, comprising:
- modifying a precursor nanotip having an apex and a shank by applying an electric field in the presence of a reactive gas to perform field-assisted etching wherein atoms are preferentially removed from the shank by chemical interaction with the reactive gas;
- and
- controlling the reactive gas pressure and/or tip voltage to vary the electric field so as to promote field evaporation of apex atoms during fabrication of the nanotip and thereby control the overall profile of the resulting nanotip.
(canceled)
(canceled)
A method as claimed in 17, wherein the tip is maintained at a temperature of approximately 1100-1400 C. for 120 s.
19-22. (canceled)
A method of rebuilding nanotips within a scanning ion microscope (SIM) or field ion microscope (FIM), comprising:
- introducing an etchant gas into a vacuum chamber of the SIM or FIM with a nanotip in situ;
- etching the nanotip having an apex and a shank with a reactive gas in the presence of an electric field to preferentially etch the shank while maintaining tip alignment within the microscope;
- and
- controlling the reactive gas pressure and/or tip voltage to vary the electric field so as to promote field evaporation of apex atoms in order to control the overall profile of the final nanotip.
A method of fabricating precursor nanotips or cleaning up nanotips, comprising:
- placing a sample tip with a shank and an apex in a vacuum chamber in the presence of an etchant gas;
- cyclically varying the voltage of an applied electric field to alternate between a field evaporation mode where field evaporation is predominant and an etching mode where chemical etching is predominant.
(canceled)
28-31. (canceled)
Dependencies are inferred from the claim text.