An Atom-Probe Tomography Primer

and quantitative data on the subnanoscale. APT both supplements and complements existing characterization instruments, such as high-resolution electron micro - An Atom-Probe scopy, scanning transmission electron microscopy, nano-secondary ion mass spectrometry, and electron energy loss Tomography spectroscopy. It is a destructive technique, as one is continuously irreversibly remov- ing atoms from a microtip specimen. The present revolutionary state of APT is Primer due to the confluence of several important technological advances over the past few decades: (1) the development of high- David N. Seidman and Krystyna Stiller, speed electronics that permit a researcher to collect large data sets (hundreds of mil- Guest Editors lions of atoms) in relatively short periods of time; (2) high pulse repetition-rate pico- and femtosecond lasers that permit one to Abstract analyze semiconductors, ceramics, biomin- Atom-probe tomography (APT) is in the midst of a dynamic renaissance as a result erals, and organic materials, in addition of the development of well-engineered commercial instruments that are both robust and to metals, without excessive specimen ergonomic and capable of collecting large data sets, hundreds of millions of atoms, in failures; (3) high-gain, 107, low-noise short time periods compared to their predecessor instruments. An APT setup involves multichannel plates (MCPs) that are used a field-ion microscope coupled directly to a special time-of-flight (TOF) mass to determine the time-of-flight (TOF) of spectrometer that permits one to determine the mass-to-charge states of individual individual ions; (4) delay-line detectors field-evaporated ions plus their x-, y-, and z-coordinates in a specimen in direct space that yield the x- and y-positions of individ- with subnanoscale resolution. The three-dimensional (3D) data sets acquired are ual atoms in an atomic plane; (5) the com- analyzed using increasingly sophisticated software programs that utilize high-end bination of a MCP and a delay-line detector workstations, which permit one to handle continuously increasing large data sets. in series to obtain a position-sensitive APT has the unique ability to dissect a lattice, with subnanometer-scale spatial detector, which yields the x-, y-, and z-coor- resolution, using either voltage or laser pulses, on an atom-by-atom and atomic plane- dinates of atoms in a 3D specimen in direct by-plane basis and to reconstruct it in 3D with the chemical identity of each detected space; (6) the implementation of dual- atom identified by TOF mass spectrometry. Employing pico- or femtosecond laser pulses beam focused ion beam (FIB) microscopy using visible (green or blue light) to ultraviolet light makes the analysis of metallic, for the preparation of a wide range of spec- semiconducting, ceramic, and organic materials practical to different degrees of success. imens, extending significant APT to prob- 2 The utilization of dual-beam focused ion-beam microscopy for the preparation of microtip lems that could not previously be studied; specimens from multilayer and surface films, semiconductor devices, and for producing and (7) relatively high-end workstations that make it possible to analyze increas- site-specific specimens greatly extends the capabilities of APT to a wider range of ingly large data sets using sophisticated scientific and engineering problems than could previously be studied for a wide range of data analysis programs. materials: metals, semiconductors, ceramics, biominerals, and organic materials. The articles in this issue of MRS Bulletin are devoted to the applications of APT to specific problems concerning structural metallic and semiconducting materials, Introduction thin films and multilayers, and organic Nothing tends so much to the period,1 because of the availability of and biological materials and is intended to advancement of knowledge as the reliable and well-engineered commercial give the reader a feeling for the current application of a new instrument. The instruments and data analysis software state of this instrument, which is in flux, native intellectual powers of men in that are both robust and ergonomic. In this and embolden him or her to perform an different times are not so much the article, we first describe the basic physical experiment with this marvelous instru- causes of the different success of principles of APT commencing with the ment, which provides quantitative chemi- their labours, as the peculiar nature field ion microscope (FIM), invented by cal information in direct space that cannot of the means and artificial resources E.W. Müller, which provided the first be obtained with other characterization in their possession. (Sir Humphry images of atoms in direct space, 54 years tools at the subnanoscale. Davy, 1778–1829) ago, on the surfaces of crystalline tungsten specimens. After explaining the basic Field Ion Microscopy in Brief This profound observation is pertinent physics of field-ion microscopy, field ion- A FIM is a lensless point-projection to this issue of MRS Bulletin on atom-probe ization, and field evaporation, we discuss microscope that resolves individual atoms tomography (APT) and its many applica- the physical concepts of modern APTs, on the surface of a sharply pointed tip, tions to an ever-widening range of mate- which permit a researcher to reconstruct radius of curvature of <50 nm, which is rial classes that involve important the positions of individual atoms in a spec- maintained at a positive potential (Vdc) scientific and technological problems in imen in three dimensions (3D) with their with respect to ground. Atomic resolution materials science and engineering. APT is chemical identities (mass-to-charge state FIM images are achieved by cooling a coming of age, after a long gestation ratios, m/n), thereby yielding meaningful microtip to between ≈20 to 120 K in an

MRS BULLETIN • VOLUME 34 • OCTOBER 2009 • www.mrs.org/bulletin 717 An Atom-Probe Tomography Primer

ultrahigh vacuum (UHV) system using a men on an atom-by-atom and atomic {hkl} V(x) closed-cycle liquid helium refrigerator plane-by-plane basis, thereby exploring Metal Vacuum and placing the microtip at Vdc to generate continuously and systematically the bulk electric fields (E) that are between 15 to 65 of a specimen. Figure 1 is a schematic dia- V nm−1.3 High-purity helium or neon gram illustrating the mechanism by which ∑I − nφ gases, or a mixture of He and Ne gases, are the barrier for an atom to “evaporate” as i 0 used to image atoms utilizing the quan- an ion is strongly reduced by the applica- 0 x tum mechanical phenomenon of field ion- tion of an E field. The height of the so- 4–9 V (x) ization. In these high E fields, He or Ne called Schottky hump, Qn(E), is a sensitive a − atoms are field ionized, ≈45 V nm 1 for He function of E that decreases with increas- Λ ≈ −1 and 35 V nm for Ne, above individual ing E: Qn(E) appears in a Boltzmann factor, –ne E surface atoms. This is because the outer- and therefore field evaporation is also x most electron of every imaging gas atom strongly temperature dependent. This quantum mechanically tunnels into the model for field evaporation is called the sharply pointed tip at the site of an atom to ionic model, as it assumes that all the x Qn(E) s V x create an atomic diameter cone of He+ or atoms on the surface of a specimen exist as i( ) + Ne ions emanating from individual sur- ions. In Figure 1, Va(x) is the potential face atoms. The field-ionized He+ or Ne+ energy of an atom in the absence of an ions are repelled from the positively electric field, and V (x) is the potential Figure 1. V(x) is potential energy as a i function of distance away from the charged ions on the surface of a microtip energy of an ion in its ith ionization state surface of a specimen, x = 0. Va(x) is (specimen) and then accelerated along the in the presence of an electric field; they the potential energy of an atom in the E field lines, which are orthogonal to the differ from one another because of a small absence of an electric field, E, and Vi(x) equipotentials, to a MCP. The energetic difference in the polarizabilities of atoms is the potential energy of an ion in its He+ or Ne+ ions are converted into visible and ions, which is E dependent. i th ionization state in the presence of E. light employing a high-gain MCP. Thus, Ii is the i th ionization state of an ion, e the physical basis of “seeing” atoms in A Primer of Atom-Probe is the charge on an electron, n is the direct space is the quantum-mechanical Tomography number of electronic charges, Λ is the cohesive energy of a solid, φ is the process of field ionization of gas atoms A truly revolutionary advance in instru- 0 local work function, Q (E) is the height associated with the high E fields at indi- mentation occurred when Müller, Panitz, n of the so-called Schottky hump, and xs vidual ions on the surface of a microtip. and McLane invented the atom-probe is the position of the maximum value of + + The field ionized He or Ne ions are the field ion microscope (APFIM) in 1968,14 the Schottky hump. information carrying messengers that per- which consisted of a FIM plus a special mit observation of individual atoms with TOF mass spectrometer, with the ability to subnanometer scale spatial resolution. The detect single pulsed-field-evaporated ions magnification of a FIM image, which is using a high-gain MCP. An APFIM uti- spatial resolution is 0.2 to 0.5 nm within an easily >2 × 106 times, is proportional to the lizes controlled pulsed field evaporation, atomic {hkl} plane, where the exact value tip-to-MCP distance divided by the aver- using either voltage or laser pulses, to depends on {hkl}. TOF mass spectrometry, age radius of curvature of a microtip. determine the TOFs of individual ions, employing a MCP, has the critical advan- Subsequently, Müller discovered the thereby determining their m/n ratios and tage that the detection sensitivity is identi- physical phenomenon of field evapora- hence their chemical identities. The cal for all elements in the periodic table tion, which is the sublimation of atoms APFIM is indeed a revolutionary instru- once the energy of a field-evaporated ion from the surface of a microtip as positively ment because it combines atomic-scale is greater than a few keV. The main limita- charged ions employing a high E field. resolution FIM images with TOF mass tion of a MCP is its detection efficiency, Müller serendipitously discovered this spectrometry.15 TOF mass spectrometry is which is approximately equal to its open 21 phenomenon by increasing Vdc(E) and based on the conservation of energy of exposed area, 50 to 60%. A position- concomitantly observing that atoms at the an evaporated ion; that is, its potential sensitive detector, Figure 2, permits both surface of a microtip are being “evapo- energy is equal to its kinetic energy.16 the TOF and x- and y- coordinates of indi- rated” as ions, thereby continuously The next ground-breaking invention vidual atoms in every {hkl} crystallo- exposing the bulk of a specimen.10–13 Field was the position-sensitive atom probe graphic plane to be determined on an evaporation is a material-dependent (PoSAP), developed by Cerezo, Godfrey, atom-by-atom and plane-by-plane basis property; for example, for tungsten, the and Smith,17,18 as a serial instrument. with respect to an atom’s 3D position in a −1 19 evaporation field (Ee) is 57 V nm and for Subsequently, Blavette et al. invented a microtip. The physical phenomenon of −1 silver is Ee = 25 V nm ; both values were truly parallel APT, which was commer- field evaporation permits a researcher to calculated at 0 K. However, Ee decreases cialized by Cameca Science & Metrology access the bulk of a microtip and to deter- with increasing temperature, T, therefore Solutions. A parallel APT permits one to mine the m/n values of all the detected the specimen must be cooled to a cryo- dissect a specimen at high pulse repetition ions with the same detection efficiency. genic temperature, typically between 20 to rates, currently up to 106 Hz for Imago Data collection is subsequently followed 120 K, to obtain stable (nonevaporating) Scientific Instrument’s APT using an by reconstruction in 3D of a given volume microtips. Field evaporation is controlled ultraviolet solid-state laser. APTs have the of material using sophisticated software by superimposing high-voltage pulses ability to reconstruct a lattice of atoms in programs. For example, a data set of × 6 (Vpulse) on top of Vdc. Alternatively, field 3D with their individual chemical identi- 240 10 atoms corresponds to a volume evaporation can be achieved by applying ties, m/n.20 The spatial depth resolution of approximately 4 × 10−21 m3 (approxi- pico- or femtosecond laser pulses. The is equal to the {hkl} interplanar spacing mately 4 × 106 nm3). One can combine, process of controlled field evaporation (<0.1 nm) along the crystallographic direc- however, data sets from different portions permits an investigator to dissect a speci- tion, , being analyzed, and the lateral of a specimen to examine even larger

718 MRS BULLETIN • VOLUME 34 • OCTOBER 2009 • www.mrs.org/bulletin An Atom-Probe Tomography Primer

position-sensitive between voltage and laser pulsing is that detector the former utilizes an increase of E using Vpulse to obtain “evaporation” of ions at a constant temperature. The exact mechanism by which laser-induced “evaporation” of ions occurs is a subject of scientific debate.30,31 For green light (532 nm wave- length) laser pulses, it is currently thought local the local temperature of a microtip is electrode I V increased, thereby causing thermally acti- pulse vated “evaporation” of an ion over a small II Schottky hump;32 in this case, the E field pulsed laser is constant during the “evaporation” process. The exact mechanism for evapo- V ration using blue (400 nm) or ultraviolet dc (355 nm) laser light also most likely involves thermally activated “evaporation” over a Schottky hump.31,32 A LEAP tomograph currently operates utilizing a pulsed picosecond laser (green light) to “evaporate” ions. The pulse repetition rate is variable in steps from 1 to 500 kHz, and a detection rate of up to 5 × 106 ions min−1 is obtainable for a cooperative Figure 2. Schematic drawing of a local-electrode atom-probe (LEAP) tomograph employing specimen, that is, one that does not fail due either voltage, I, or laser pulses, II. The substrate, which contains an array of microtip to fracture: the fracture of specimens specimens, is maintained at a positive potential, Vdc; the substrate can be translated in the occurs less frequently with laser light than x-y plane. The local electrode is pulsed with a negative voltage, Vpulse, to increase the with electrical pulses because the so-called E-field at a microtip specimen to the requisite value for field evaporating atoms as ions. Maxwell mechanical stresses are smaller. Alternatively, a specimen is pulsed with femto- or picosecond laser pulses at a high The laser variable parameters are energy repetition rate. II—blue laser light. A field ion microscope (FIM) looks physically identical to a LEAP tomograph, but it does not have a delay-line detector. The multichannel plate is per pulse, pulse duration, pulse repetition used to obtain a FIM image of the atoms on the surface of a microtip employing helium or rate, and wave length of the laser light. The neon as an imaging gas. Thus, a LEAP tomograph also can be used as a FIM. FWHM m/Δm value is 1200, and the FWTM m/Δm value is 300 for 27Al+, with the microtip at 120 mm from the compos- volumes of material and concomitantly detector at a variable distance of between ite position-sensitive detector for green improve the counting statistics. 90 and 120 mm from the microtip, thereby laser light. The momentum dispersion of Commencing in 1999, a local-electrode permitting a researcher to vary the magni- the evaporating ions, due to pulses that are atom-probe (LEAP) tomograph was fication of a FIM image and/or the TOF not delta functions, is smaller for laser fabricated and commercialized by distance. The MCP plus the delay-line pulsing than for electrical pulsing because Imago Scientific Instruments.22–26 (The detector measure an ion’s TOF and its the ions only have an average thermal idea for a local electrode originated with position within an atomic plane: the spa- energy kBT, where kB is Boltzmann’s Nishikawa and Kimoto,27 who employed tial accuracy of the delay-line detector is constant and T is the temperature of it in a scanning atom probe (SAP). In a <0.2 mm, with a timing accuracy of 50 ps the microtip, when they surmount the SAP, the local electrode is scanned from and a multihit resolution of 1.5 ns.28 Schottky hump. Thus the spread in the one microtip specimen to another Employing electrical pulses, the repetition TOFs, for a given m/n value, is smaller, microtip specimen to maximize the rate is variable in discrete steps from 1 to which results in larger values of m/Δm. amount of collected data.) The LEAP 250 kHz, and a detection rate of up to 2 × For either electrical or laser pulsing, the tomograph employs a local electrode with 106 ion min−1 can be achieved. The full- cross-sectional area of an analyzed a 30-μm diameter orifice, which is placed width at half-maximum (FWHM) value microtip specimen can be 200 × 200 nm2 at within ca. 30 μm of a microtip specimen; of the mass resolving power (m/Δm) is 500 a distance of 90 mm from the position- the local electrode decreases the voltage for 27Al+, and the full-width at tenth- sensitive detector, employing an 80 mm necessary to achieve the requisite E field maximum (FWTM) m/Δm value is 180, diameter MCP. The depth to which a for field evaporation. Figure 2 is a with the microtip at 120 mm from the microtip can be analyzed is material schematic diagram of a LEAP tomograph composite position-sensitive detector: Δm dependent and may be upward of one operating in the scanning mode. An array is typically measured either at FWHM or micrometer plus. The detection sensitivity of microtip specimens sits on a conducting FWTM of a peak in the mass spectrum. is currently about 10 atomic parts per mil- substrate at Vdc. To field-evaporate atoms In 1980, Kellogg and Tsong replaced lion for green laser light, with the standard as ions, the local electrode is pulsed with a high-voltage pulses with laser pulses to error being determined solely by counting negative potential, Vpulse, which increases permit analysis of less conductive materi- statistics. The use of UV lasers is currently the local E field at a microtip to the als, semiconductors, and metal oxides.29 not widespread, and hence there is only a required value; a typical pulse fraction, This approach involves maintaining a limited amount of published results avail- Vpulse/Vdc, is 0.15 to 0.25. The position-sen- specimen at Vdc and applying short laser able concerning their use. They are, how- sitive detector consists of an 80-mm diam- pulses (<1 ns) to obtain field-evaporation ever, significantly better for studying eter MCP in series with a delay-line of ions, Figure 2. The physical difference nonmetallic materials (semiconductors,

MRS BULLETIN • VOLUME 34 • OCTOBER 2009 • www.mrs.org/bulletin 719 An Atom-Probe Tomography Primer

52 ceramics, biominerals) than green lasers, a Slice sample from wedge d which opens up many new applications 40 microns of APT. Recently, a single-stage wide-angle reflectron lens has been developed that increases the obtainable m/Δm values b Wedge Manipulator with a field-of-view that is comparable to that obtained using an APT with a straight Pt weld 33 TOF path length. The combination of 40 microns using pulsed-laser light with a single- c Cantilever effect stage wide-angle reflectron lens yields even larger values of m/Δm than a reflec- Microtip post tion lens with voltage pulsing. The negative aspect of a wide-angle reflection lens is that the overall detection efficiency is decreased because of the necessity of 5 microns 10 microns using a high-transparency (95+%) metal mesh grid to define a ground plane.34 Figure 3. Preparation of a microtip from a Si wafer containing a device. (a) Initial mill cuts for wedge lift-out from a Si wafer containing a device. (b) Close-up image showing the Specimen Preparation wedge still attached to the Si wafer. The long wedge forms a cantilever-type structure. Specimen preparation is of crucial (c) Wedge extracted from the wafer. (d) Sample wedge mounted to a microtip structure importance for APT studies. Traditionally, using a micromanipulator and then sliced free from the remaining wedge employing a + 2 electropolishing methods were exten- low-energy Ga ion beam. sively used to fabricate sharply pointed microtips (radius of curvature <50 nm) from whiskers, wires, or blanks hogged ing a device. A more exhaustive descrip- The Kelly et al. article reviews the historical out of bulk material.35 Additionally, using tion of the different specimen preparation developments in the application of APT pulsed millisecond electropolishing in techniques is described elsewhere.51 to organic and biological materials, presents concert with a double-axis tilt-stage for a some recent results, and discusses applica- TEM,36,37 one can bring a specific Specific Materials and Problems tions that life science researchers might microstructural feature, for example, a Studied by Atom-Probe expect from this technology. grain boundary38–42 or a precipitate, into Tomography the volume of material accessible for APT The following four articles in this spe- Summary analyses. Electropolishing has been used cial issue discuss applications of APT to In this short beginner’s guide to atom- extensively for metallic alloys,43 internally scientific and technological problems for probe tomography (APT), we have pre- oxidized metallic alloys containing metal- four different materials classes: (1) struc- sented the basic physical concepts of this oxide precipitates,44 silicon, and metallic45 tural materials; (2) thin films and multilay- instrument and discussed briefly the con- or semiconductor46 compounds. It is, ers; (3) semiconductor materials and fluence of technologies that make possible however, problematic for preparing elec- device structures; and (4) organic and bio- the fabrication of high-quality sophisti- trically nonconducting specimens and logical materials. cated instruments, which are now capable also specimens containing specific fea- The Marquis et al. article on structural of analyzing material chemically for a tures that are close to a specimen’s surface, materials focuses on metallic alloys and wide range of materials on a subnanome- such as a low-energy ion-implanted demonstrates the key roles played by APT ter scale. The four remaining articles in this region, multilayer thin films, magnetic in helping to understand structure- property special issue demonstrate the utilization of oxide tunnel junctions, or individual com- relations in this class of materials. APT is APT for a wide range of materials and plementary metal-oxide semiconductor used to study, for example, clustering, the physical problems that we trust will serve transistors in an integrated circuit. genesis of second phases, and the as an aperitif for using this instrument for Dual-beam FIB microscopy47 and its microstructural defects that control an a problem that is of interest to you. application to the fabrication of APT alloy’s high-temperature mechanical prop- microtip specimens has dramatically erties. This information provides an Acknowledgments improved the ability to prepare microtips unprecedented level of atomic-scale detail D.N.S. is greatly indebted to the of different materials in different configu- on the origins of aging behavior, strength, National Science Foundation (NSF), rations. This methodology relies on using creep, fracture toughness, corrosion, and Department of Energy (DOE), Office low-energy Ga+ ions to sputter material irradiation resistance. The Larson et al. arti- of Naval Research (ONR), Air Force with a high accuracy48 so that a microtip cle on thin films and multilayers focuses on Office of Scientific Research (AFOSR), can be made to contain a desired nanos- growth and reactions within thin-metal and Semiconductor Research Corporation, tructural feature. Currently, dual-beam FIB oxide films using APT to understand them IBM Watson Laboratory, and the Ford- microscopy is extensively used for prepa- and allow further optimization of devices Boeing-Northwestern Alliance for sup- ration of microtip specimens from multi- based on thin films. The Lauhon et al. article port of his research, and to the NSF MRI layer and surface films,49 semiconductor on semiconductor materials and device and ONR DURIP programs for instru- devices, and for producing site-specific structures emphasizes laser-assisted APT mentation grants for an atom-probe specimens.50 Figure 3 is an example of the research on metal-silicide contact formation tomograph. We also thank D. Perea for use of the lift-out technique to prepare a and phase control, silicon field-effect transis- Figures 1 and 2 and D.J. Larson for Figure microtip for APT from a Si wafer contain- tors, and silicon and germanium nanowires. 3 and comments on the manuscript.

720 MRS BULLETIN • VOLUME 34 • OCTOBER 2009 • www.mrs.org/bulletin An Atom-Probe Tomography Primer

References 19. D. Blavette, B. Deconihut, A. Bostel, J.M. 36. B.W. Krakauer, J.G. Hu, S.M. Kuo, 1. D.N. Seidman, Rev. Sci. Instrum. 78, 030901 Sarru, M. Bouet, A. Menand, Rev. Sci. Instrum. R.L. Mallick, A. Seki, D.N. Seidman, J.P. Baker, (2007). 64, 2911 (1993). R. Loyd, Rev. Sci. Instrum. 61, 3390 2. K. Thompson, D.J. Lawrence, D.J. Larson, 20. M.K. Miller, Atom Probe Tomography: (1990). J.D. Olson, T.F. Kelly, B.P. Gorman, Analysis at the Atomic Level (Kluwer Academic, 37. B.W. Krakauer, D.N. Seidman, Rev. Sci. Ultramicroscopy 107, 131 (2007). Plenum Publishers, New York, 2000). Instrum. 63, 4071 (1992). 3. E.W. Müller, T.T. Tsong, Field Ion Microscopy 21. J.A. Panitz, J.A. Foesch, Rev. Sci. Instrum. 47, 38. A. Henjered, H. Nordén, J.Phys. E: Sci Instr. (American Elsevier Publishing Company, New 44 (1976). 16, 617 (1983). York, 1969). 22. T.F. Kelly, P.P. Camus, D.J. Larson, L.M. 39. L. Karlsson, H. Nordén, Acta Metall. 36 4. J.R. Oppenheimer, Phys. Rev. 31, 67 (1928). Holzman, S.S. Bajikav, Ultramicroscopy 62, 29 (1988). 5. M.G. Inghram, R. Gomer, J. Chem. Phys. 22, (1996). 40. K. Stiller, Colloque Phys. C8, 329 (1989). 1279 (1954). 23. T.F. Kelly, D.J. Larson, Mater. Charact. 44, 59 41. B.W. Krakauer, D.N. Seidman, Acta Mater. 6. M.G. Inghram, R. Gomer, Z. Naturforsch. 10a, (2000). 46, 6145 (1998). 863 (1955). 24. A.A. Gribb, T.F. Kelly, Adv. Mater. Proc. 162 42. D.N. Seidman, Annu. Rev. Mater. Res. 32, 7. E.W. Müller, K. Bahadur, Phys. Rev. 102, 624 (2), 31 (2004). 235 (2002). (1956). 25. S.S.A. Gerstl, D.N. Seidman, A.A. Gribb, 43. R. Herschitz, D.N. Seidman, Surf. Sci. 130, 8. E.W. Müller, K. Bahadur, Phys. Rev. 99, 1651 T.F. Kelly, Adv. Mater. Proc. 162 (10), 31 63 (1983). (1955). (2004). 44. D.A. Shashkov, D.N. Seidman, Phys. Rev. 9. R. Gomer, Field Emission and Field Ionization 26. K. Thompson, J.H. Bunton, T.F. Kelly, D.J. Lett. 75, 268 (1995). (Harvard University Press, Cambridge, MA, Larson, J. Vac. Sci. Technol., B 24 (1), 421 (2006). 45. M. Yamamoto, D.N. Seidman, Surf. Sci. 118, 1961), pp. 64–102. 27. O. Nishikawa, M. Kimoto, Appl. Surf. Sci. 76 535 (1982). 10. E.W. Müller, Phys. Rev. 102, 618 (1956). (1–4), 424 (1994). 46. M. Yamamoto, D.N. Seidman, S. 11. R. Gomer, J. Chem. Phys. 31, 341 (1959). 28. G. da Costa, F. Vurpillot, A. Bostel, M. Nakamura, Surf. Sci. 118, 555 (1982). 12. R. Gomer, L.W. Swanson, J. Chem. Phys. 38, Bouet, B. Deconihout, Rev. Sci. Instrum. 76, 47. L.A. Giannuzzi, F.S. Stevie, Micron 30, 197 1613 (1963). 013304 (2005). (1999). 13. D.G. Brandon, Surf. Sci. 3, 1 (1965). 29. G.L. Kellogg, T.T. Tsong, J. Appl. Phys. 51, 48. D.J. Larson, D.T. Foord, A.K. Petford-Long, 14. E.W. Müller, J.A. Panitz, S.B. McLane, Rev. 1184 (1980). H. Liew, M.G. Blamire, A. Cerezo, G.D.W. Sci. Instrum. 39, 83 (1968). 30. B. Gault, F. Vurpillot, A. Bostel, A. Menand, Smith, Ultramicroscopy 79, 287 (1999). 15. T.T. Tsong, Atom-Probe Field-Ion Microscopy B. Deconihout, Appl. Phys. Lett. 86, 094101 49. D.J. Larson, A.K. Petford-Long, Y.Q. Ma, A. (Cambridge University Press, Cambridge, MA, (2005). Cerezo, Acta Mater. 52, 2847 (2004). 1990). 31. A. Cerezo, G.D.W. Smith, P.H. Clifton, Appl. 50. B. Gault, A. Menand, F. de Geuser, B. 16. E de Hoffmann, V. Stroubant, Mass Phys. Lett. 88, 154103 (2006). Deconihout, F. Danoix, Appl. Phys. Lett. 88, Spectrometry (Wiley-Interscience, New York, 32. G.L. Kellogg, J. Appl. Phys. 52, 5320 (1981). 114101 (2006). 2007). 33. P. Panayi, Great Britain Patent Application 51. M.K. Miller, K.F. Russell, K. Thompson, R. 17. A. Cerezo, T.J. Godfrey, G.D.W. Smith, Rev. GB2426120A (November 15, 2006). Alvis, D.J. Larson, Microsc. Microanal. 13 (6), 428 Sci. Instrum. 59, 862 (1988). 34. M.R. Scheinfein, D.N. Seidman, Rev. Sci. (2007). 18. M.K. Miller, A. Cerezo, M.G. Hetherington, Instrum. 64, 3126 (1993). 52. Y.M. Chen, T. Ohkubo, M. Kodzuka, K. G.D.W. Smith, Atom Probe Field Ion Microscopy 35. D.N. Seidman, Annu. Rev. Mater. Res. 37, Morita, K. Hono, Scripta Mater. 61, 693–696 (Oxford University Press, Oxford, 1996). 127 (2007). (2009). ■

ing at Cornell University. acterization of doping and Alexander Von Humboldt Seidman is the founding defectivity of individual Stiftung Prize (1989), and director of the CMOS transistors using a Max Planck Research Northwestern University atom-probe tomography. Prize jointly with the late Center for Atom-Probe Seidman has published professor Peter Haasen Tomography (NUCAPT). more than 325 scientific (1993). From the TMS Some of his current articles and co-edited Society, he received a research interests are in eight conference proceed- Robert Lansing Hardy the kinetics of first-order ings and special journal Gold Medal (1966), phase transformations in issues. He has been the Advanced Characterization model nickel-based super editor-in-chief of Interface and Modeling of Phase alloys, the development Science and is a member Transformations in Metals of high-temperature alu- of the editorial board of Symposium in his honor at David N. Seidman Krystyna Stiller minum-scandium–based MRS Bulletin. He also is a the TMS 2009 Annual alloys, the development fellow of the American Meeting, and the TMS and characterization of Physical Society (con- Institute of Metals Lecture David N. Seidman, Guest Materials Science and ultrahigh strength explo- densed matter physics and the Robert Franklin Editor for this issue of Engineering at sion resistant steels, solidi- division), The Minerals, Mehl Award for 2011. He MRS Bulletin, can be Northwestern University. fication defects in Metals and Materials received an Albert reached at Northwestern He graduated from the nickel-based super alloys, Society (TMS), and ASM Sauveur Achievement University, Evanston, IL University of Illinois at the surface chemistry of International. Seidman Award, ASM 60208-3108, USA; and Urbana-Champaign with ultrahigh purity niobium has twice been a John International (2006), and e-mail d-seidman@ a PhD degree. Prior to for superconducting Simon Guggenheim received the David northwestern.edu. September 1985, Seidman radiofrequency cavities, Memorial Foundation fel- Turnbull Lecturer Award Seidman is a Walter P. was a professor of materi- and high spatial resolu- low (1972 to 1973 and from the Materials Murphy Professor of als science and engineer- tion/high precision char- 1980 to 1981); won an Research Society in 2008.

MRS BULLETIN • VOLUME 34 • OCTOBER 2009 • www.mrs.org/bulletin 721 An Atom-Probe Tomography Primer

Praneet Adusumilli Didier Blavette Alfred Cerezo Philip L. Flaitz Kazuhiro Hono

Krystyna Stiller, Guest Didier Blavette can be (three-dimensional atom Hono is a fellow of the position in the group of Editor for this issue of reached by e-mail at probe) and the first high National Institute for Professor Hillebrands at MRS Bulletin, can be Didier.blavette@ mass resolution 3DAP Materials Science (NIMS) the University of reached at tel. univ-rouen.fr. with a reflectron. His and a principal investi - Kaiserslautern, Germany. +46 31 772 33 20; e-mail Blavette is a professor of current research interests gator at the WPI Center Juraszek’s research [email protected]. physics at the University include the modeling and for Materials Nanoarchi- interests are focused on Stiller has worked in of Rouen, France. He also characterization of techtronics at NIMS. magnetic multilayers and the Department of is the head of the Groupe atomic-scale microstruc- He is also a professor of the optimization of their Applied Physics in the de Physique des tural features and their materials science in the magnetic properties by Division of Microscopy Matériaux (UMR CNRS role in determining mate- Graduate School of Pure ion irradiation effects. and Microanalysis at 6634), comprising 100 sci- rials properties. Cerezo’s and Applied Sciences at Chalmers University of entists. Blavette is a spe- honors include the E.W. the University of Thomas F. Kelly can be Technology in Göteborg, cialist of diffusive phase Müller Outstanding Tsukuba, Japan. Hono reached at Imago Sweden since 1973. She transformations and Young Scientist Medal received his PhD degree Scientific Instruments received her BSc in instrumentation (develop- (1988), the C.R. Burch in metals science and Corporation, 5500 Nobel physics in 1974 and a PhD ment of the tomographic Prize (2000), and the Sir engineering from Penn Dr., Madison, WI 53711, in physics in 1980 from atom probe). He is co- George Beilby Medal and State in 1988. Following a USA; tel. 608-274-6880, Göteborg University. Her author of more than 200 Prize (2001). post-doctoral stay at ext. 211; and e-mail research interests include articles and reviews and Carnegie Mellon [email protected]. the processes of phase has been invited to more Philip L. Flaitz can be University, he spent five Kelly is currently chief transformations and stud- than 50 international reached at IBM years at the Institute for executive officer and chief ies of the microstructure meetings. In addition, Microelectronics, 2070 Materials Research at technical officer of Imago and composition of thin Blavette has received sev- Route 52, Hopewell Tohoku University as a Scientific Instruments surface layers and grain eral prizes in physics and Junction, NY 12533, USA; research associate. Hono Corporation. He received boundaries. materials science, among tel. 845-892-3094; and then moved to NIMS his BS degree in mechani- them the silver medal e-mail [email protected]. (formerly NRIM) as a cal engineering from Praneet Adusumilli can awarded by the CNRS Flaitz is a transmission senior researcher in 1995. Northeastern University be reached at the (Centre National de la electron microscopy His research interests and a PhD degree in Department of Materials Recherche Scientifique). (TEM) analyst in IBM’s include microstructure- materials science from the Science and Engineering, He has been a member of Semiconductor Research property relationships of Massachusetts Institute of Northwestern University, the Institut Universitaire and Development magnetic and spintronics Technology in 1981. Kelly Evanston, IL 60208, USA; de France since 2007. Center, providing materi- materials, nanostructure was a professor in the tel. 847-491-5946; and als characterization for characterization by atom Department of Materials e-mail Praneet@ Alfred Cerezo can be semiconductor and pack- probe, and transmission Science and Engineering northwestern.edu. reached at alfred.cerezo aging development and electron microscopy. at the University of Adusumilli is a PhD @materials.ox.ac.uk. manufacturing and Wisconsin-Madison from degree candidate in the Cerezo is a professor exploring enhanced char- Jean Juraszek can be 1983 to 2001. In 1998, he Department of Materials of materials at the acterization techniques reached at jean.juraszek@ founded Imago to com- Science and Engineering University of Oxford. He by TEM. He received his univ-rouen.fr. mercialize the local- at Northwestern graduated with a degree PhD degree in materials Juraszek is an assistant electrode atom-probe University and has in physics and obtained a science and engineering professor at the Groupe (LEAP) tomograph. received a bachelor’s doctorate in materials at from the University of de Physique des degree in metallurgical Oxford; he was a Royal California, Berkeley. Matériaux, Rouen David J. Larson can be engineering from Society University University in France. reached at tel. Banaras Hindu research fellow from 1988 Kazuhiro Hono can be After he obtained his PhD +1 608-274-6880; University, India. He to 1995. With his co- reached at tel. degree in materials sci- and e-mail dlarson@ works on atom-probe workers at Oxford, +81-298-59-2718; and ence from the University imago.com. characterization of novel Cerezo built the first fully e-mail kazuhiro.hono@ of Rouen, Juraszek held a Larson is currently vice silicide contacts. operational 3DAP nims.go.jp. postdoctoral research president of applications

722 MRS BULLETIN • VOLUME 34 • OCTOBER 2009 • www.mrs.org/bulletin An Atom-Probe Tomography Primer

Jean Juraszek Thomas F. Kelly David J. Larson Lincoln J. Lauhon Dan Lawrence

research at Imago University in 2000, and engineering from of Materials Science and Erwin W. Müller in the Scientific Instruments and Lauhon became involved Northwestern University Engineering, 7-1 Field Emission Laboratory an honorary staff member in nanowire research as a in 2002. She then went to Ohgigaoka, Nonoichi, at Pennsylvania State in the Australian Key postdoctoral fellow in the Sandia National Ishikawa 921-8501, University, where he co- Centre for Microscopy laboratory of Professor Laboratories in Livermore, Japan; and e-mail invented the atom probe and Microanalysis at the Charles M. Lieber at CA, before joining Oxford nisikawa@neptune. field ion microscope. After University of Sydney. He Harvard University, in 2007 to manage the 3D kanazawa-it.ac.jp. graduation, Panitz joined obtained his PhD degree where he developed new atom-probe UK facility. Nishikawa has been a Sandia National in materials science from approaches to the fabrica- Her research interests research professor at the Laboratories in the University of tion of nanowire het- (alloy stability, solutes/ Kanazawa Institute of Albuquerque, New Wisconsin in 1996. After erostructures and devices. defects interactions, devel- Technology, Japan, since Mexico, where he devel- fellowships at Oak Ridge opment of new analysis 1992. He earned his BS oped the 10-cm atom- National Laboratory Dan Lawrence can be tools for atom-probe degree in physics from probe mass spectrometer, (ORNL) and the reached at Imago tomography data) are Osaka University and his the archetype of commer- University of Oxford, Scientific Instruments, now focused on structural MS and PhD degrees in cial atom probe instru- Larson worked for ORNL Inc., 5500 Nobel Dr., materials for nuclear physics working in the ments. After 15 years with as a research staff mem- Madison, WI 53711, USA; applications and develop- laboratory of Professor Sandia, Panitz joined the ber and at Seagate tel. 608-274-6880, ext. 251; ing novel atom-probe Erwin Müller at faculty of the University Technology as a staff and e-mail tomography applications. Pennsylvania State of New Mexico. In 1993, engineer. In 2005, he was [email protected]. University. Nishikawa he founded High-Field awarded the Burton Lawrence is an applica- Michael K. Miller can be was a faculty member Consultants. Medal by the Microscopy tions specialist at Imago reached by e-mail at there from 1967 to 1976. Society of America for Scientific Instruments, [email protected]. He also worked as a vis- Ty J. Prosa can be reached exceptional achievement focusing on atom probe Miller is a iting researcher at Bell at Imago Scientific in microscopy and of semiconductor device Distinguished R&D Staff Telephone Laboratory at Instruments Corporation, microanalysis. material systems. He has Member in the Materials Murray Hill. From 1976 5500 Nobel Dr., Madison, previously worked as an Science and Technology to 1992, he was a profes- WI 53711, USA; tel. 608- Lincoln J. Lauhon can engineer at IBM Division at Oak Ridge sor at the Tokyo Institute 274-6880; and e-mail be reached at Microelectronics in National Laboratory of Technology. [email protected]. Northwestern University, Burlington, VT, and as a (ORNL). He received his Prosa has been an appli- Evanston, IL 60208, USA; staff technician at the doctorate from the J.A. Panitz can be cations scientist at Imago tel. 847-491-2232; and University of Wisconsin Department of reached at the since 2005. He received his e-mail lauhon@ Center for Plasma-Aided Metallurgy and Science Department of Physics BS degree in physics and northwestern.edu. Manufacturing in of Materials at the and Astronomy, MSC07 math from the University Lauhon is the Morris E. Madison, WI. University of Oxford in 4220 1, University of of Wisconsin-Eau Claire Fine Junior Professor of 1977. Miller was a visit- New Mexico, and his MS and PhD Materials and Emmanuelle A. Marquis ing scientist at the U.S. Albuquerque, NM 87131- degrees in physics from Manufacturing in the can be reached by e-mail Steel Research Laboratory 0001, USA; e-mail the University of Department of Materials at emmanuelle.marquis@ in Monroeville, PA, from panitz@HighField Wisconsin-Madison. After Science and Engineering materials.ox.ac.uk. 1979 until he moved to consultants.com. an NRC postdoctoral asso- at Northwestern Marquis is a Royal ORNL in 1983. He is a Panitz is an emeritus ciateship at NIST- University. His research Society Dorothy TMS fellow and has professor of physics and Gaithersburg in the group seeks to establish Hodgkin Fellow in the authored more than 430 an emeritus professor of polymers division, Prosa the ultimate limits of dop- Department of Materials papers and 3 books. cell biology and physiol- held positions at ing and composition at the University of ogy in the School of Kutztown University of modulation in semicon- Oxford. After attending Osamu Nishikawa can Medicine at the University Pennsylvania and ductor nanowires. After the Ecole des Mines de be reached at the of New Mexico. He Hamline University in earning his PhD degree in Paris, she earned a PhD Kanazawa Institute of received his PhD degree Saint Paul, MN, teaching physics from Cornell degree in materials science Technology, Department in physics from Professor liberal arts physics and

MRS BULLETIN • VOLUME 34 • OCTOBER 2009 • www.mrs.org/bulletin 723 An Atom-Probe Tomography Primer

Emmanuelle Michael K. Miller Osamu Nishikawa J.A. Panitz Ty J. Prosa A. Marquis

Simon P. Ringer Paul A. Ronsheim Guido Schmitz George D.W. Smith Chantal K. Sudbrack conducting undergraduate the Australian Micro - 0251/83-33572; and Smith is a professor of After attending Reed research. Prosa has a back- scopy and Microanalysis e-mail gschmitz@ materials science at College and Columbia ground in x-ray diffraction Research Facility. uni-muenster.de. Oxford University, UK. University, she received studies of polymer struc- Schmitz has been a pro- His research interests lie her PhD degree in ture and more recently has Paul A. Ronsheim can fessor in material physics in the study of the struc- materials science and focused on specimen be reached at IBM at Westfälische Wilhelms- ture, composition, and engineering from preparation research and Microelectronics, 2070 Rt. University in Münster, properties of materials at Northwestern University development for use in 52, Hopewell Junction, Germany, since 2002. He the atomic level. Smith in 2004. Her PhD studies atom-probe tomography. NY 12533, USA; studied physics and theol- was awarded the Beilby with Professor David N. tel. 845-892-2298; and ogy at the Universities of Medal and Prize (1985) Seidman used atom- Simon P. Ringer can be e-mail ronsheim@us. Freiburg and Goettingen, and the Rosenhain Medal probe tomography to reached by e-mail at ibm.com. receiving his PhD degree (1991). He was elected to study nucleation and [email protected]. Ronsheim is an in 1994. Schmitz has held the fellowship of the growth mechanisms in Ringer is director of engineer at IBM’s guest professorships at Royal Society in 1996, Ni-based superalloys. the Australian Key Semiconductor Research the University of received the 2005 Acta Before joining NASA in Centre for Microscopy and Development Center California, Los Angeles Materialia Gold Medal, 2009, Sudbrack was a and Microanalysis at the and provides materials (2000), and the University and the 2006 Institute of postdoctoral researcher at University of Sydney, and process analysis for of Rouen in France (2008). Materials Platinum Northwestern University where he is a professor of semiconductor device His expertise is in the Medal for his contribu- and Argonne National materials science and development, with an physical mechanisms of tions to materials science Laboratory. Sudbrack microscopy. He earned emphasis on SIMS (sec- solid-state reactions, cor- and technology. Smith is was appointed TMS his PhD degree from the ondary ion mass spec- relation between atomic the author or co-author Young Intern for 2006 by University of New South trometry) and ion transport and stress, and of 2 books and more than The Minerals, Metals & Wales and a BappSc scattering techniques. He interfacial chemistry. His 300 scientific papers. Materials Society Struc - degree in metallurgy received his PhD degree current research in the tural Materials Division. from the University of in materials science at the areas of technical applica- Chantal K. Sudbrack can Her research interests South Australia. Ringer University of Minnesota. tion includes solder joints be reached by e-mail at include microstrucural has held various aca- Ronsheim is currently and all-solid-state thin- chantal.sudbrack@nasa. development, phase demic and industry posi- developing atom-probe film batteries. gov. transformations, and tions in Sweden, Japan, tomography for device Sudbrack is a materials interfacial phenomena in United States, and measurements. George D.W. Smith can research engineer at the high-temperature struc- Australia. He also serves be reached by e-mail at NASA Glenn Research tural materials. She is a as chief executive officer Guido Schmitz can be george.smith@materials. Center in the Materials member of various TMS and executive director of reached at tel. ox.ac.uk. and Structures Division. committees. ■

724 MRS BULLETIN • VOLUME 34 • OCTOBER 2009 • www.mrs.org/bulletin