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Microwave Frequency Comb from a Semiconductor in a Scanning Tunneling Microscope

Published online by Cambridge University Press:  20 December 2016

Mark J. Hagmann ,
Dmitry A. Yarotski  and
Marwan S. Mousa
Mark J. Hagmann*
Affiliation:
Department of Electrical and Computer Engineering, University of Utah, Salt Lake City, UT 84112, USA NewPath Research LLC, Salt Lake City, UT 84115, USA
Dmitry A. Yarotski
Affiliation:
Los Alamos National Laboratory, Center for Integrated Nanotechnologies, Materials Physics and Applications Division, Los Alamos, NM 87545, USA
Marwan S. Mousa
Affiliation:
Department of Physics, Mu’tah University, Al-Karak 61710, Jordan
*
*Corresponding author.mhagmann@newpathresearch.com
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Abstract

Quasi-periodic excitation of the tunneling junction in a scanning tunneling microscope, by a mode-locked ultrafast laser, superimposes a regular sequence of 15 fs pulses on the DC tunneling current. In the frequency domain, this is a frequency comb with harmonics at integer multiples of the laser pulse repetition frequency. With a gold sample the 200th harmonic at 14.85 GHz has a signal-to-noise ratio of 25 dB, and the power at each harmonic varies inversely with the square of the frequency. Now we report the first measurements with a semiconductor where the laser photon energy must be less than the bandgap energy of the semiconductor; the microwave frequency comb must be measured within 200 μm of the tunneling junction; and the microwave power is 25 dB below that with a metal sample and falls off more rapidly at the higher harmonics. Our results suggest that the measured attenuation of the microwave harmonics is sensitive to the semiconductor spreading resistance within 1 nm of the tunneling junction. This approach may enable sub-nanometer carrier profiling of semiconductors without requiring the diamond nanoprobes in scanning spreading resistance microscopy.

Keywords

scanning tunneling microscopyscanning probe microscopymicrowave frequency combspreading resistancelaser-assisted tunneling
Type
Related Techniques
Information
Microscopy and Microanalysis , Volume 23 , Special Issue 2: Atom Probe Tomography & Microscopy 2016 , April 2017 , pp. 443 - 448
Copyright
© Microscopy Society of America 2016 

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References

Doloca, N.R., Meiners-Hagen, K., Wedde, M., Pollinger, F. & Abou-Zeid, A. (2010). Absolute distance measurement system using a femtosecond laser as a modulator. Meas Sci Technol 21, 115302.Google Scholar
Flores, F. & Garcia, N. (1984). Voltage drop in the experiments of scanning tunneling microscopy for Si. Phys Rev B 20, 2289–2291.Google Scholar
Gelmont, B. & Shur, S. (1993). Spreading resistance of a round ohmic contact. Solid State Electron 36, 143–146.Google Scholar
Germanicus, R.C., Leclere, P., Guhel, Y., Boudart, B., Touboul, A.D., Deschamps, P., Hug, E. & Eybedn, P. (2015). On the effects of a pressure induced amorphous silicon layer on consecutive spreading resistance microscopy scans of doped silicon. J Appl Phys 117, 244306.CrossRefGoogle Scholar
Grafstrom, S. (2002). Photoassisted scanning tunneling microscopy. J Appl Phys 91, 1717–1753.Google Scholar
Hagmann, M.J., Andrei, P., Pandey, S. & Nahata, A. (2015). Possible applications of scanning frequency comb microscopy for carrier profiling in semiconductors. J Vac Sci Technol B 33, 02B109.Google Scholar
Hagmann, M.J., Efimov, A., Taylor, A.J. & Yarotski, D.A. (2011). Microwave frequency-comb generation in a tunneling junction by intermode mixing of ultrafast laser pulses. Appl Phys Lett 99, 011112.Google Scholar
Hagmann, M.J. & Mousa, M.S. (2007). Simulation of sub-femtosecond response in laser-assisted field emission. Ultramicroscopy 107, 849–853.CrossRefGoogle ScholarPubMed
Hagmann, M.J., Pandey, S. & Yarotski, D.A. (2012 a). Microwave frequency comb attributed to the formation of dipoles at the surface of a semiconductor by a mode-locked ultrafast laser. Appl Phys Lett 101, 231102.Google Scholar
Hagmann, M.J., Stenger, F.S. & Yarotski, D.A. (2013). Linewidth of the harmonics in a microwave frequency comb generated by focusing a mode-locked ultrafast laser on a tunneling junction. J Appl Phys 114, 223107.CrossRefGoogle Scholar
Hagmann, M.J., Taylor, A.J. & Yarotski, D.A. (2012 b). Observation of 200th harmonic with fractional linewidth of 10−10 in a microwave frequency comb generated in a tunneling junction. Appl Phys Lett 101, 241102.CrossRefGoogle Scholar
Lin, M.E., Ma, Z., Huang, F.Y., Fan, Z.F., Allen, L.H. & Morkoc, H. (1994). Low resistance ohmic contacts on wide band-gap GaN. Appl Phys Lett 64, 1003–1005.Google Scholar
Pollock, C.R., Jennings, D.A., Petersen, F.R., Wells, J.S., Drullinger, R.E., Beaty, E.C. & Evenson, K.M. (1983). Direct frequency measurements of transitions at 520 THz (576 nm) in iodine and 260 THz (1.15 µm) in neon. Opt Lett 8, 133–135.Google Scholar
Vandervorst, W., Schulze, A., Kambham, A.K., Mody, J., Gilbert, M. & Eyben, P. (2014). Dopant/carrier profiling for 3D-structures. Phys Status Solidi C 11, 121–129.Google Scholar
Yasui, T., Yokoyama, S., Inaba, H., Minoshima, K., Nagatsuma, T. & Araki, T. (2011). Terahertz frequency metrology based on frequency comb. IEEE J Sel Top Quantum Electron 17, 191–201.CrossRefGoogle Scholar