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New perspectives on nano-engineering by secondary electron spectroscopy in the helium ion and scanning electron microscope

Published online by Cambridge University Press:  23 April 2018

Nicola Stehling Open the ORCID record for Nicola Stehling [Opens in a new window] ,
Robert Masters ,
Yangbo Zhou ,
Robert O'Connell ,
Chris Holland Open the ORCID record for Chris Holland [Opens in a new window] ,
Hongzhou Zhang  and
Cornelia Rodenburg Open the ORCID record for Cornelia Rodenburg [Opens in a new window]
Nicola Stehling
Affiliation:
University of Sheffield Faculty of Engineering, Material Science and Engineering, Sheffield, S1 3JD, UK
Robert Masters
Affiliation:
University of Sheffield Faculty of Engineering, Material Science and Engineering, Sheffield, S1 3JD, UK
Yangbo Zhou
Affiliation:
Nanchang University, School of Material Science and Engineering, Nanchang, Jiangxi, 330031, China
Robert O'Connell
Affiliation:
University of Dublin Trinity College, School of Physics, Dublin 2, Ireland
Chris Holland
Affiliation:
University of Sheffield Faculty of Engineering, Material Science and Engineering, Sheffield, S1 3JD, UK
Hongzhou Zhang
Affiliation:
University of Dublin Trinity College, School of Physics, Dublin 2, Ireland
Cornelia Rodenburg*
Affiliation:
University of Sheffield Faculty of Engineering, Material Science and Engineering, Sheffield, S1 3JD, UK
*
Address all correspondence to Cornelia Rodenburg at [email protected]
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Abstract

The helium ion microscope (HeIM) holds immense promise for nano-engineering and imaging with scope for in-situ chemical analysis. Here we will examine the potential of secondary electron hyperspectral imaging (SEHI) as a new route to exploring chemical variations in both two and three dimensions. We present a range of early applications in the context of image interpretation in wider materials science and process control in ion beam-based nano-engineering. Necessary steps for SEHI in the HeIM to evolve into a reliable technique which can be fully embedded into nano-engineering workflows are considered.

Type
Prospective Articles
Information
MRS Communications , Volume 8 , Issue 2 , June 2018 , pp. 226 - 240
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Copyright © Materials Research Society 2018 

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References

1.Sasaki, N.: An ion microscope with a transverse magnetic field. J. Appl. Phys. 19, 1050–1053 (1948), doi: 10.1063/1.1698008.Google Scholar
2.Komuro, M., Atoda, N., and Kawakatsu, H.: Ion beam exposure of resist materials. J. Electrochem. Soc. 126, 483–490 (1979).Google Scholar
3.Krohn, V.E. and Ringo, G.R.: Ion source of high brightness using liquid metal. Appl. Phys. Lett. 27, 479–481 (1975).Google Scholar
4.Levi-Setti, R.: Proton scanning microscopy: feasibility and promise. In Scanning Electron Microscopy, 1st ed.; Johari, O. ed.; IITRI, Chicago, USA, 1974, pp. 125–135.Google Scholar
5.Seliger, R.L., Ward, J.W., Wang, V., and Kubena, R.L.: A high-intensity scanning ion probe with submicrometer spot size. Appl. Phys. Lett. 34, 310–312 (1979).CrossRefGoogle Scholar
6.Swanson, L.W.: Liquid metal ion sources: mechanism and applications. Nucl. Instruments Methods Phys. Res. 218, 347–353 (1983).CrossRefGoogle Scholar
7.Ward, B.W., Notte, J.A., and Economou, N.P.: Helium ion microscope: a new tool for nanoscale microscopy and metrology. J. Vac. Sci. Technol. B Microelectron. Nanom. Struct. Process. Meas. Phenom. 24, 2871–2874 (2006).Google Scholar
8.Livengood, R.H., Tan, S., Hallstein, R., Notte, J., McVey, S., and Faridur Rahman, F.H.M.: The neon gas field ion source—a first characterization of neon nanomachining properties. Nucl. Instruments Methods Phys. Res. Sect. A Accel. Spectrometers, Detect. Assoc. Equip. 645, 136–140 (2011), doi: https://doi.org/10.1016/j.nima.2010.12.220.Google Scholar
9.Rahman, F.H.M., McVey, S., Farkas, L., Notte, J.A., Tan, S., and Livengood, R.H.: The prospects of a subnanometer focused neon ion beam. Scanning 34, 129–134 (2012), doi: 10.1002/sca.20268.CrossRefGoogle ScholarPubMed
10.Fox, D., Chen, Y., Faulkner, C.C., and Zhang, H.: Nano-structuring, surface and bulk modification with a focused helium ion beam. Beilstein J. Nanotechnol. 3, 579 (2012).Google Scholar
11.Zhou, Y., Maguire, P., Jadwiszczak, J., Muruganathan, M., Mizuta, H., and Zhang, H.: Precise milling of nano-gap chains in graphene with a focused helium ion beam. Nanotechnology 27, 325302 (2016).Google Scholar
12.Lemme, M.C., Bell, D.C., Williams, J.R., Stern, L.A., Baugher, B.W.H., Jarillo-Herrero, P., and Marcus, C.M.: Etching of graphene devices with a helium ion beam. ACS Nano 3, 2674–2676 (2009).Google Scholar
13.Bell, D.C., Lemme, M.C., Stern, L.A., Williams, J.R., and Marcus, C.M.: Precision cutting and patterning of graphene with helium ions. Nanotechnology 20, 455301 (2009).Google Scholar
14.Fox, D.S., Zhou, Y., Maguire, P., O'Neill, A., Ó’Coileáin, C., Gatensby, R., Glushenkov, A.M., Tao, T., Duesberg, G.S., and Shvets, I.V.: Nanopatterning and electrical tuning of MoS2 layers with a subnanometer helium ion beam. Nano Lett. 15, 5307–5313 (2015).CrossRefGoogle ScholarPubMed
15.Philipp, P., Rzeznik, L., and Wirtz, T.: Numerical investigation of depth profiling capabilities of helium and neon ions in ion microscopy. Beilstein J. Nanotechnol. 7, 1749 (2016).Google Scholar
16.Joens, M.S., Huynh, C., Kasuboski, J.M., Ferranti, D., Sigal, Y.J., Zeitvogel, F., Obst, M., Burkhardt, C.J., Curran, K.P., and Chalasani, S.H.: Helium ion microscopy (HIM) for the imaging of biological samples at sub-nanometer resolution. Sci. Rep. 3, 3514 (2013).Google Scholar
17.Tan, S., Livengood, R., Hack, P., Hallstein, R., Shima, D., Notte, J., and McVey, S.: Nanomachining with a focused neon beam: a preliminary investigation for semiconductor circuit editing and failure analysis. J. Vac. Sci. Technol. B, Nanotechnol. Microelectron. Mater. Process. Meas. Phenom. 29, 06F604 (2011).Google Scholar
18.Rzeznik, L., Fleming, Y., Wirtz, T., and Philipp, P.: Experimental and simulation-based investigation of He, Ne and Ar irradiation of polymers for ion microscopy. Beilstein J. Nanotechnol. 7, 1113 (2016).Google Scholar
19.Maguire, P., Fox, D.S., Zhou, Y., Wang, Q., O'Brien, M., Jadwiszczak, J., McManus, J., McEvoy, N., Duesberg, G.S., and Zhang, H.: Defect sizing, distance and substrate effects in ion-irradiated monolayer 2D materials. arXiv (2017), http://arxiv.org/abs/1707.08893.Google Scholar
20.Melngailis, J.: Focused ion beam lithography. Nucl. Instruments Methods Phys. Res. Sect. B Beam Interact. with Mater. Atoms 80, 1271–1280 (1993).CrossRefGoogle Scholar
21.Shi, X., Prewett, P., Huq, E., Bagnall, D.M., Robinson, A.P.G., and Boden, S.A.: Helium ion beam lithography on fullerene molecular resists for sub-10nm patterning. Microelectron. Eng. 155, 74–78 (2016).Google Scholar
22.Wu, H., Stern, L.A., Xia, D., Ferranti, D., Thompson, B., Klein, K.L., Gonzalez, C.M., and Rack, P.D.: Focused helium ion beam deposited low resistivity cobalt metal lines with 10 nm resolution: implications for advanced circuit editing. J. Mater. Sci. Mater. Electron. 25, 587–595 (2014).CrossRefGoogle Scholar
23.Stanford, M.G., Lewis, B.B., Mahady, K., Fowlkes, J.D., and Rack, P.D.: Advanced nanoscale patterning and material synthesis with gas field helium and neon ion beams. J. Vac. Sci. Technol. B, Nanotechnol. Microelectron. Mater. Process. Meas. Phenom. 35, 30802 (2017).Google Scholar
24.Belianinov, A., Burch, M.J., Kim, S., Tan, S., Hlawacek, G., and Ovchinnikova, O.S.: Noble gas ion beams in materials science for future applications and devices. MRS Bull. 42, 660–666 (2017), doi: 10.1557/mrs.2017.185.Google Scholar
25.Huth, M., Porrati, F., Schwalb, C., Winhold, M., Sachser, R., Dukic, M., Adams, J., and Fantner, G.: Focused electron beam induced deposition: a perspective. Beilstein J. Nanotechnol. 3, 597 (2012).Google Scholar
26.Joy, D.C., and Griffin, B.J.: Is microanalysis possible in the helium ion microscope?. Microsc. Microanal. 17, 643–649 (2011).Google Scholar
27.Ramachandra, R., Griffin, B., and Joy, D.: A model of secondary electron imaging in the helium ion scanning microscope. Ultramicroscopy 109, 748–757 (2009).Google Scholar
28.Scipioni, L., Sanford, C.A., Notte, J., Thompson, B., and McVey, S.: Understanding imaging modes in the helium ion microscope. J. Vac. Sci. Technol. B Microelectron. Nanom. Struct. Process. Meas. Phenom. 27, 3250–3255 (2009), doi: 10.1116/1.3258634.Google Scholar
29.Sijbrandij, S., Thompson, B., Notte, J., Ward, B.W., and Economou, N.P.: Elemental analysis with the helium ion microscope. J. Vac. Sci. Technol. B Microelectron. Nanom. Struct. Process. Meas. Phenom. 26, 2103–2106 (2008).Google Scholar
30.Klingner, N., Heller, R., Hlawacek, G., von Borany, J., Notte, J., Huang, J., and Facsko, S.: Nanometer scale elemental analysis in the helium ion microscope using time of flight spectrometry. Ultramicroscopy 162, 91–97 (2016), doi: 10.1016/j.ultramic.2015.12.005.Google Scholar
31.Veligura, V., Hlawacek, G., van Gastel, R., Zandvliet, H.J.W., and Poelsema, B.: Channeling in helium ion microscopy: mapping of crystal orientation. Beilstein J. Nanotechnol. 3, 501 (2012).CrossRefGoogle ScholarPubMed
32.Wirtz, T., Philipp, P., Audinot, J.N., Dowsett, D., and Eswara, S.: High-resolution high-sensitivity elemental imaging by secondary ion mass spectrometry: from traditional 2D and 3D imaging to correlative microscopy. Nanotechnology 26, 434001 (2015).Google Scholar
33.Wirtz, T., Vanhove, N., Pillatsch, L., Dowsett, D., Sijbrandij, S., and Notte, J.: Towards secondary ion mass spectrometry on the helium ion microscope: an experimental and simulation based feasibility study with He+and Ne+bombardment. Appl. Phys. Lett. 101, 41601 (2012).CrossRefGoogle Scholar
34.Dowsett, D. and Wirtz, T.: Co-registered in situ secondary electron and mass spectral imaging on the helium ion microscope demonstrated using lithium titanate and magnesium oxide nanoparticles. Anal. Chem. 89, 8957–8965 (2017).Google Scholar
35.Vollnhals, F., Audinot, J.-N., Wirtz, T., Mercier-Bonin, M., Fourquaux, I., Schroeppel, B., Kraushaar, U., Lev-Ram, V., Ellisman, M.H., and Eswara, S.: Correlative microscopy combining secondary ion mass spectrometry and electron microscopy: comparison of intensity–hue–saturation and Laplacian pyramid methods for image fusion. Anal. Chem. 89, 10702–10710 (2017).CrossRefGoogle ScholarPubMed
36.Gratia, P., Grancini, G., Audinot, J.-N., Jeanbourquin, X., Mosconi, E., Zimmermann, I., Dowsett, D., Lee, Y., Grätzel, M., and De Angelis, F.: Intrinsic halide segregation at nanometer scale determines the high efficiency of mixed cation/mixed halide perovskite solar cells. J. Am. Chem. Soc. 138, 15821–15824 (2016).Google Scholar
37.Gratia, P., Zimmermann, I., Schouwink, P., Yum, J.-H., Audinot, J.-N., Sivula, K., Wirtz, T., and Nazeeruddin, M.K.: The many faces of mixed ion perovskites: unraveling and understanding the crystallization process. ACS Energy Lett. 2, 2686–2693 (2017), doi: 10.1021/acsenergylett.7b00981.Google Scholar
38.Everhart, T.E. and Thornley, R.F.M.: Wide-band detector for micro-microampere low-energy electron currents. J. Sci. Instrum. 37, 246 (1960).Google Scholar
39.Lai, S.Y., Brown, A., Vickerman, J.C., and Briggs, D.: The relationship between electron and ion induced secondary electron imaging: a review with new experimental observations. Surf. Interface Anal. 8, 93–111 (1986).CrossRefGoogle Scholar
40.Baragiola, R.A., Alonso, E. V, Ferron, J., and Oliva-Florio, A.: Ion-induced electron emission from clean metals. Surf. Sci. 90, 240–255 (1979).Google Scholar
41.Ferron, J., Alonso, E. V, Baragiola, R.A., and Oliva-Florio, A.: Electron emission from molybdenum under ion bombardment. J. Phys. D. Appl. Phys. 14, 1707 (1981).Google Scholar
42.Hill, R. and Rahman, F.H.M.F.: Advances in helium ion microscopy. Nucl. Instruments Methods Phys. Res. Sect. A Accel. Spectrometers, Detect. Assoc. Equip. 645, 96–101 (2011).CrossRefGoogle Scholar
43.Notte, J., Ward, B., Economou, N., Hill, R., Percival, R., Farkas, L., and McVey, S.: An introduction to the helium ion microscope. AIP Conf. Proc. 931, 489–496 (2007).Google Scholar
44.Rodenburg, C., Viswanathan, P., Jepson, M.A.E., Liu, X., and Battaglia, G.: Helium ion microscopy based wall thickness and surface roughness analysis of polymer foams obtained from high internal phase emulsion. Ultramicroscopy 139, 13–19 (2014).Google Scholar
45.Tsuji, K., Suleiman, H., Miner, J.H., Daley, J.M., Capen, D.E., Păunescu, T.G., and Lu, H.A.J.: Ultrastructural characterization of the glomerulopathy in Alport mice by helium ion scanning microscopy (HIM). Sci. Rep. 7, 11696 (2017).Google Scholar
46.Tsuji, K., Păunescu, T.G., Suleiman, H., Xie, D., Mamuya, F.A., Miner, J.H., and Lu, H.A.J.: Re-characterization of the glomerulopathy in CD2AP deficient mice by high-resolution helium ion scanning microscopy. Sci. Rep. 7, 8321 (2017).Google Scholar
47.Rice, W.L., Van Hoek, A.N., Păunescu, T.G., Huynh, C., Goetze, B., Singh, B., Scipioni, L., Stern, L.A., and Brown, D.: High resolution helium ion scanning microscopy of the rat kidney. PLoS ONE 8, e57051 (2013), doi: 10.1371/journal.pone.0057051.Google Scholar
48.Bazou, D., Behan, G., Reid, C., Boland, J.J., and Zhang, H.Z.: Imaging of human colon cancer cells using He-Ion scanning microscopy. J. Microsc. 242, 290–294 (2011).CrossRefGoogle ScholarPubMed
49.Rodenburg, C., Liu, X., Jepson, M.A.E., Zhou, Z., Rainforth, W.M., and Rodenburg, J.M.: The role of helium ion microscopy in the characterisation of complex three-dimensional nanostructures. Ultramicroscopy 110, 1178–1184 (2010).Google Scholar
50.Joy, D.C. and Joy, C.S.: Low voltage scanning electron microscopy. Micron 27, 247–263 (1996).CrossRefGoogle Scholar
51.Joy, D.C.: Control of charging in low-voltage SEM. Scanning 11, 1–4 (1989).Google Scholar
52.Jepson, M.A.E., Inkson, B.J., Rodenburg, C., and Bell, D.C.: Dopant contrast in the helium ion microscope. Europhys. Lett. 85, 46001 (2009).Google Scholar
53.Rodenburg, C., Jepson, M.A.E., Inkson, B.J., and Liu, X.: Dopant contrast in the helium ion microscope: contrast mechanism. J. Phys. Conf. Ser. 241, 12076 (2010).Google Scholar
54.Iberi, V., Vlassiouk, I., Zhang, X.G., Matola, B., Linn, A., Joy, D.C., and Rondinone, A.J.: Maskless lithography and in situ visualization of conductivity of graphene using helium ion microscopy. Sci. Rep. 5, 11952 (2015), doi: 10.1038/srep11952.CrossRefGoogle ScholarPubMed
55.Petrov, Y.V., Vyvenko, O.F., and Bondarenko, A.S.: Scanning helium ion microscope: distribution of secondary electrons and ion channeling. J. Surf. Investig. X-Ray, Synchrotron Neutron Tech. 4, 792–795 (2010).Google Scholar
56.Mikhailovskii, V.Y., Petrov, Y. V, and Vyvenko, O.F.: Energy filtration of secondary and backscattered electrons by the method of the retarding potential in scanning electron and ion microscopy. J. Surf. Investig. X-Ray, Synchrotron Neutron Tech. 9, 196–202 (2015), doi: 10.1134/S1027451014060378.Google Scholar
57.Petrov, Y.V., and Vyvenko, O.F.: Secondary electron generation in the helium ion microscope: basics and imaging. In Helium Ion Microscopy, 1st ed.; Hlawacek, G., Gölzhäuser, A. eds.; Springer International Publishing, Cham, Switzerland, 2016, pp. 119–146, doi: 10.1007/978-3-319-41990-9_5.Google Scholar
58.Ohya, K., Yamanaka, T., Inai, K., and Ishitani, T.: Comparison of secondary electron emission in helium ion microscope with gallium ion and electron microscopes. Nucl. Instruments Methods Phys. Res. Sect. B Beam Interact. Mater. Atoms 267, 584–589 (2009).Google Scholar
59.Suzuki, M.K.T., Sakai, Y., and Ichinokawa, T.: Material contrast of scanning electron and ion microscope images of metals. Micros. Today 16, 6–10 (2008).Google Scholar
60.Kumar, V., Schmidt, W.L., Schileo, G., Masters, R.C., Wong-Stringer, M., Sinclair, D.C., Reaney, I.M., Lidzey, D., and Rodenburg, C.: Nanoscale mapping of bromide segregation on the cross sections of complex hybrid perovskite photovoltaic films using secondary electron hyperspectral imaging in a scanning electron microscope. ACS Omega 2, 2126–2133 (2017).Google Scholar
61.Bruining, D.H.: 5 - Variation of Secondary Emission Yield Caused by The External Adsorption of Ions and Atoms. In Physics and Applications of Secondary Electron Emission, 2nd ed.; Pergamon Press, London, England, 1962, pp. 69–77, doi: 10.1016/B978-0-08-009014-6.50008-9.CrossRefGoogle Scholar
62.Willis, R.F., Fitton, B., and Skinner, D.K.: Study of carbon-fiber surfaces using Auger and secondary electron emission spectroscopy. J. Appl. Phys. 43, 4412–4419 (1972).Google Scholar
63.Joy, D.C., Prasad, M.S., and Meyer, H.M.: Experimental secondary electron spectra under SEM conditions. J. Microsc. 215, 77–85 (2004).CrossRefGoogle ScholarPubMed
64.Chung, M.S. and Everhart, T.E.: Simple calculation of energy distribution of low-energy secondary electrons emitted from metals under electron bombardment. J. Appl. Phys. 45, 707–709 (1974).Google Scholar
65.Schönjahn, C., Humphreys, C.J., and Glick, M.: Energy-filtered imaging in a field-emission scanning electron microscope for dopant mapping in semiconductors. J. Appl. Phys. 92, 7667–7671 (2002), doi: 10.1063/1.1525862.Google Scholar
66.Kazemian, P., Mentink, S.A.M., Rodenburg, C., and Humphreys, C.J.: High resolution quantitative two-dimensional dopant mapping using energy-filtered secondary electron imaging. J. Appl. Phys. 100, 54901 (2006).Google Scholar
67.Jepson, M.A.E., Inkson, B.J., Liu, X., Scipioni, L., and Rodenburg, C.: Quantitative dopant contrast in the helium ion microscope. Europhys. Lett. 86, 26005 (2009).CrossRefGoogle Scholar
68.O'Connell, R., Chen, Y., Zhang, H., Zhou, Y., Fox, D., Maguire, P., Wang, J.J., and Rodenburg, C.: Comparative study of image contrast in scanning electron microscope and helium ion microscope. J. Microsc. 268, 313–320 (2017).Google Scholar
69.Griffin, B.J.: A comparison of conventional Everhart-Thornley style and in-lens secondary electron detectors—a further variable in scanning electron microscopy. Scanning 33, 162–173 (2011).Google Scholar
70.Rodenburg, C., Jepson, M.A.E., Bosch, E.G.T., and Dapor, M.: Energy selective scanning electron microscopy to reduce the effect of contamination layers on scanning electron microscope dopant mapping. Ultramicroscopy 110, 1185–1191 (2010).Google Scholar
71.Zhou, Y., Fox, D.S., Maguire, P., O'Connell, R., Masters, R., Rodenburg, C., Wu, H., Dapor, M., Chen, Y., and Zhang, H.: Quantitative secondary electron imaging for work function extraction at atomic level and layer identification of graphene. Sci. Rep. 6, 21045 (2016).Google Scholar
72.Kazemian, P., Mentink, S.A.M., Rodenburg, C., and Humphreys, C.J.: Quantitative secondary electron energy filtering in a scanning electron microscope and its applications. Ultramicroscopy 107, 140–150 (2007).Google Scholar
73.Dapor, M., Masters, R.C., Ross, I., Lidzey, D.G., Pearson, A., Abril, I., Garcia-Molina, R., Sharp, J., Unčovský, M., Vystavel, T., Mika, F., and Rodenburg, C.: “Secondary electron spectra of semi-crystalline polymers – A novel polymer characterisation tool?” J. Electron Spectros. Relat. Phenomena 222, 95–105 (2018), doi: 10.1016/j.elspec.2017.08.001.CrossRefGoogle Scholar
74.Livengood, R.H., Greenzweig, Y., Liang, T., and Grumski, M.: Helium ion microscope invasiveness and imaging study for semiconductor applications. J. Vac. Sci. Technol. B Microelectron. Nanom. Struct. Process. Meas. Phenom. 25, 2547–2552 (2007), doi: 10.1116/1.2794319.Google Scholar
75.Wan, Q., Abrams, K.J., Masters, R.C., Talari, A., Rehman, I.U., Claeyssens, F., Holland, C., and Rodenburg, C.: Mapping nanostructural variations in silk by secondary electron hyperspectral imaging. Adv. Mater. 29, 1703510 (2017), doi: 10.1002/adma.201703510.Google Scholar
76.Strauss, M.G., Naday, I., Sherman, I.S., and Zaluzec, N.J.: CCD-based parallel detection system for electron energy-loss spectroscopy and imaging. Ultramicroscopy 22, 117–123 (1987), doi: 10.1016/0304-3991(87)90055-6.Google Scholar
77.Hart, J.L., Lang, A.C., Leff, A.C., Longo, P., Trevor, C., Twesten, R.D., and Taheri, M.L.: Direct detection electron energy-loss spectroscopy: a method to push the limits of resolution and sensitivity. Sci. Rep. 7, 8243 (2017), doi: 10.1038/s41598-017-07709-4.Google Scholar
78.Khursheed, A.: Scanning Electron Microscope Optics and Spectrometers, 1st ed.; World Scientific Co Pte, Singapore, 2010.Google Scholar
79.Masters, R.C., Pearson, A.J., Glen, T.S., Sasam, F.-C., Li, L., Dapor, M., Donald, A.M., Lidzey, D.G., and Rodenburg, C.: Sub-nanometre resolution imaging of polymer-fullerene photovoltaic blends using energy-filtered scanning electron microscopy. Nat. Commun. 6, (2015).CrossRefGoogle ScholarPubMed
80.Abrams, K.J., Wan, Q., Stehling, N.A., Jiao, C., Talari, A.C.S., Rehman, I., and Rodenburg, C.: Nanoscale mapping of semi-crystalline polypropylene. Phys. Status Solidi 14, 1700153 (2017).Google Scholar
81.Liu, Y., Zhao, J., Li, Z., Mu, C., Ma, W., Hu, H., Jiang, K., Lin, H., Ade, H., and Yan, H.: Aggregation and morphology control enables multiple cases of high-efficiency polymer solar cells. Nat. Commun. 5, 5293 (2014), doi: 10.1038/ncomms6293.Google Scholar
82.Bell, D.C.: Contrast mechanisms and image formation in helium ion microscopy. Microsc. Microanal. 15, 147–153 (2009).Google Scholar
83.Hasselkamp, D.: Kinetic electron emission from solid surfaces under ion bombardment. In Particle Induced Electron Emission II; Hasselkamp, D., Rothard, H., Groeneveld, K.-O., Kemmler, J., Varga, P., Winter, H. eds.; Springer, Berlin, Germany, 1992, pp. 1–95, doi: 10.1007/BFb0038298.Google Scholar
84.Noriega, R., Rivnay, J., Vandewal, K., Koch, F.P. V, Stingelin, N., Smith, P., Toney, M.F., and Salleo, A.: A general relationship between disorder, aggregation and charge transport in conjugated polymers. Nat. Mater. 12, 1038 (2013), doi: 10.1038/nmat3722.Google Scholar
85.Joe, H.-E., Lee, W.-S., Jun, M.B.G., Park, N.-C., and Min, B.-K.: Material interface detection based on secondary electron images for focused ion beam machining. Ultramicroscopy 184, 37–43 (2018), doi: 10.1016/j.ultramic.2017.10.012.Google Scholar
86.Ferrón, J., Vidal, R.A., Bajales, N., Cristina, L., and Baragiola, R.A.: Role of HOPG density of empty electronic states above vacuum on electron emission spectra induced by ions and UV photons. Surf. Sci. 622, 83–86 (2014).Google Scholar
87.Fox, D., Zhou, Y.B., O'Neill, A., Kumar, S., Wang, J.J., Coleman, J.N., Duesberg, G.S., Donegan, J.F., and Zhang, H.Z.: Helium ion microscopy of graphene: beam damage, image quality and edge contrast. Nanotechnology 24, 335702 (2013).Google Scholar
88.Barnett, C.J., Gowenlock, C.E., Welsby, K., Orbaek White, A., and Barron, A.R.: Spatial and contamination-dependent electrical properties of carbon nanotubes. Nano Lett. 18, 695–700 (2017), doi: 10.1021/acs.nanolett.7b03390.Google Scholar
89.Hoffman, A.: Fine structure in the secondary electron emission spectrum as a spectroscopic tool for carbon surface characterization. Diam. Relat. Mater. 3, 691–695 (1994).Google Scholar
90.Pearson, A.J., Boden, S.A., Bagnall, D.M., Lidzey, D.G., and Rodenburg, C.: Imaging the bulk nanoscale morphology of organic solar cell blends using helium ion microscopy. Nano Lett. 11, 4275–4281 (2011).Google Scholar