Etching sharp tips from thin metallic wires for tuning-fork-based scanning probe microscopy

Krantz, Patrick Wallace; Chandrasekhar, Venkat

doi:10.1116/1.5132848

Title: Etching sharp tips from thin metallic wires for tuning-fork-based scanning probe microscopy

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Abstract

Sharp tips are critical for obtaining high resolution images in scanning probe microscopy (SPM), particularly in samples with large variations in topography. For tuning-fork-based SPM, such tips are commonly obtained by electrochemical etching of metallic wires (e.g., tungsten). Electrochemical etching of metallic wires is the preferred means of preparing tips for scanning tunneling microscopy (STM), and techniques for obtaining sharp tips have been investigated extensively. However, the requirements for STM and tuning-fork-based SPM are different. In particular, the wires used in STM are typically 250-500 μm in diameter, while the wires used for tuning-fork-based SPM are usually an order of magnitude narrower in order to minimize loading of the tuning fork: 25-50 μm and sometimes down to a few micrometers in diameter. Consequently, many of the recipes developed for etching thicker metallic wires for STM tips do not give optimal results for smaller diameter wires. The authors describe here a modification of the etching circuit of Ibe et al. that significantly improves the reproducibility and reliability of the etching process for thin wires, and discuss the parameters that affect the aspect ratio of produced tips.

Authors:

^[1]; Chandrasekhar, Venkat ^[1]

Northwestern Univ., Evanston, IL (United States)

Publication Date:: Sun Mar 01 00:00:00 EST 2020

Research Org.:: Northwestern Univ., Evanston, IL (United States)

Sponsoring Org.:: USDOE Office of Science (SC)

OSTI Identifier:: 1800393

Alternate Identifier(s):: OSTI ID: 1598386

Grant/Contract Number:: FG02-06ER46346

Resource Type:: Accepted Manuscript

Journal Name:: Journal of Vacuum Science and Technology B

Additional Journal Information:: Journal Volume: 38; Journal Issue: 2; Journal ID: ISSN 2166-2746

Publisher:: American Vacuum Society / AIP

Country of Publication:: United States

Language:: English

Subject:: 42 ENGINEERING; Engineering; Science & Technology - Other Topics; Physics; Scanning tunneling microscopy; Operational amplifier; Scanning probe microscopy; Electrolytes; Etching; Field effect transistors; Tuning forks; Chemical solutions; Electrochemistry; Comparators

Citation Formats


                    Krantz, Patrick Wallace, and Chandrasekhar, Venkat. Etching sharp tips from thin metallic wires for tuning-fork-based scanning probe microscopy.  United States: N. p., 2020. 
Web.  doi:10.1116/1.5132848.

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                    Krantz, Patrick Wallace, & Chandrasekhar, Venkat. Etching sharp tips from thin metallic wires for tuning-fork-based scanning probe microscopy.  United States.  https://doi.org/10.1116/1.5132848

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                    Krantz, Patrick Wallace, and Chandrasekhar, Venkat. Sun .  
"Etching sharp tips from thin metallic wires for tuning-fork-based scanning probe microscopy".  United States.  https://doi.org/10.1116/1.5132848.  https://www.osti.gov/servlets/purl/1800393.

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@article{osti_1800393,

  title        = {Etching sharp tips from thin metallic wires for tuning-fork-based scanning probe microscopy},

  author       = {Krantz, Patrick Wallace and Chandrasekhar, Venkat},

  abstractNote = {Sharp tips are critical for obtaining high resolution images in scanning probe microscopy (SPM), particularly in samples with large variations in topography. For tuning-fork-based SPM, such tips are commonly obtained by electrochemical etching of metallic wires (e.g., tungsten). Electrochemical etching of metallic wires is the preferred means of preparing tips for scanning tunneling microscopy (STM), and techniques for obtaining sharp tips have been investigated extensively. However, the requirements for STM and tuning-fork-based SPM are different. In particular, the wires used in STM are typically 250-500 μm in diameter, while the wires used for tuning-fork-based SPM are usually an order of magnitude narrower in order to minimize loading of the tuning fork: 25-50 μm and sometimes down to a few micrometers in diameter. Consequently, many of the recipes developed for etching thicker metallic wires for STM tips do not give optimal results for smaller diameter wires. The authors describe here a modification of the etching circuit of Ibe et al. that significantly improves the reproducibility and reliability of the etching process for thin wires, and discuss the parameters that affect the aspect ratio of produced tips.},

  doi          = {10.1116/1.5132848},

  journal      = {Journal of Vacuum Science and Technology B},

  number       = 2,

  volume       = 38,

  place        = {United States},

  year         = {Sun Mar 01 00:00:00 EST 2020},

  month        = {Sun Mar 01 00:00:00 EST 2020}

}

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