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Title
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Preamble: Rutherford and IBA
Introduction
1. I.1. Interactions with electrons
2. I.2. Elastic scattering from nuclei
3. I.3. Nuclear reactions
1 Fundamentals of Ion-solid Interactions with a Focus on the Nanoscale
1. 1.1. General considerations
2. 1.2. Basic physical concepts
3. 1.3. Channeling, shadowing and blocking
4. 1.4. 1D layers: limits to depth resolution
5. 1.5. 2D and 3D objects: aspects of lateral resolution
2 Instruments and Methods
1. 2.1. Instruments
2. 2.2. Methods
3 Applications
1. 3.1. Example of resonances/light element profiling
2. 3.2. Quantitative analysis/heavy element profiling
3. 3.3. Examples of HR-ERD analysis
4. 3.4. Channeling/defect profiling
5. 3.5. Blocking/strain profiling
6. 3.6. 3D MEIS/real space structural analysis
4 The Place of NanoIBA in the Characterization Forest
1. 4.1. Introduction
2. 4.2. Scope of physical and chemical characterization
3. 4.3. Ion-based characterization techniques overview
4. 4.4. Ion-mass-spectroscopy-based characterization techniques versus IBA
5. 4.5. Other characterization techniques versus IBA
6. 4.6. Emerging ion-beam-based techniques
List of Acronyms
Bibliography
Index
End User License Agreement

List of Tables

3 Applications
1. Table 3.1. Lattice parameters and energy band gap for the wurtzite phase of AlN, GaN and InN compounds
2. Table 3.2. Areal densities of different oxygen isotopes before and after annealing in ¹⁸O₂ atmosphere (P=10⁻² Torr of ¹⁸O₂) at 490°C for 30 min
4 The Place of NanoIBA in the Characterization Forest
1. Table 4.1. Overview of the physical and chemical properties qualifying a material
2. Table 4.2. Typical characterization techniques versus primary and secondary particles as defined in Figure 4.1 (bold acronyms relate to IBA)
3. Table 4.3. Classification of ion-based characterization techniques (bold short names relate to light ions used as primary particles)

List of Illustrations

Introduction
1. Figure I.1. Sensitivity of PIXE as a function of atomic number and proton energy for organic samples [JOH 76]
1 Fundamentals of Ion-solid Interactions with a Focus on the Nanoscale
1. Figure 1.1. Photon wavelength and de Broglie wavelengths of different particles as a function of energy. The top gray area corresponds to the typical distances between atoms within a solid. The bottom gray area corresponds to the nuclear dimensions
2. Figure 1.2. According to the 2θ deviation of the X-ray beam, the phase shift between photons scattered by adjacent planes causes constructive (left figure) or destructive (right figure) interferences
3. Figure 1.3. (Left) Maximum intensities of a 10 keV X-ray beam diffracted by atomic planes spaced by 0.2 nm according to Bragg’s law (θ/2θ configuration). (Right) Laue diffraction pattern of a Ge(111) wafer (European Synchrotron Radiation Facility, IF-BM32 beamline)
4. Figure 1.4. (Left) Maximum intensities of a 200 keV electron beam diffracted by atomic planes spaced by 0.2 nm according to Bragg’s law (θ/2θ configuration). (Right) typical diffraction pattern obtained with a 200 keV electron beam on a silicon crystal [ROU 16]
5. Figure 1.5. (Left) Maximum intensities of 100 keV proton and helium ion beams diffracted by atomic planes spaced by 0.2 nm according to Bragg’s law (θ/2θ configuration). Diffraction (GIFAD) images recorded with 400 eV He on the c(2 × 2) reconstructed ZnSe(001) surface along the [110] direction [KHE 09]
6. Figure 1.6. Full width at half maximum of a diffraction peak as a function of the crystallite size
7. Figure 1.7. Penetration depths of X-rays [SEL 93], electrons [KAN 72] hydrogen ions [AND 77] and helium ions [ZIE 77] in silicon
8. Figure 1.8. Stopping cross-section of: (top) protons in silicon [AND 77] – (bottom) alphas in silicon [ZIE 77]
9. Figure 1.9. Penetration depths of helium ions [ZIE 77] and hydrogen ions [AND 77] in silicon
10. Figure 1.10. Calculated trajectories of protons in the first micron of a silicon sample for two incident energies (left) 100 keV – (right) 2 MeV [AND 77]. The calculation was made using the SRIM software [ZIE 04]
11. Figure 1.11. Calculated values of straggling for protons and helium ions through different targets (data from [CHU 76])
12. Figure 1.12. Calculated trajectory of a 100-keV proton in the vicinity of a silicon nucleus with an impact parameter of 100 fm. The diameter of the Si nucleus, about 7.5 fm, and that of the proton (1.7 fm) are not to scale in this figure. The positions of the two nuclei over time are indicated by numbering from 1 to 6 corresponding to time intervals of 1 × 10^–4 fsec. In this simulation, the proton comes from the right-hand side of the figure and is scattered upward by the silicon nucleus initially at rest at the position X = Y = 0
13. Figure 1.13. Variation of the kinematic factor for helium ions as a function of the mass of the target atoms for three different scattering angles (30°, 90° and 165°)
14. Figure 1.14. Variation of the kinematic factor for helium ions as a function of the scattering angle for four elements (C, Si, Ge and Hf)
15. Figure 1.15. Scattering cross-sections as a function of the atomic number at a scattering angle of 90° for an incident helium beam of different kinetic energies (0.1, 0.2, 1 and 2 MeV)
16. Figure 1.16. Scattering cross-section of silicon as a function of the scattering angle for an incident helium beam at different energies (0.1, 0.2, 1 and 2 MeV)
17. Figure 1.17. Angular dependence of the screening correction factors of the Rutherford cross-section for an incident helium beam scattered by gold at different energies (0.25, 0.5, 1 and 2 MeV). The dotted lines correspond to the correction, independent of the scattering angle, given by L’Ecuyer et al. [LEC 79] (equation [1.14]) and the solid lines correspond to the correction factor, dependent of the scattering angle, given by Andersen et al. [AND 80] (equation [1.15])
18. Figure 1.18. Schematic representation of the trajectories of channeled protons (the vertical distance scale has been greatly expanded in this figure to allow visualization of trajectories)
19. Figure 1.19. Critical angle of [001] channeling in silicon as a function of ion beam energy
20. Figure 1.20. Channeling half-wavelength in the [100] direction of silicon as a function of ion beam energy
21. Figure 1.21. χ_min values for protons and helium ions channeled in silicon along the <110> direction
22. Figure 1.22. Calculated trajectories of 100 keV protons in the vicinity of a silicon nucleus (the silicon nucleus diameter, about 7.5 fm, is not to scale in this figure and the Coulomb potential used is unscreened)
23. Figure 1.23. Diagram illustrating the calculation of the shadow cone radius. The incident particle approaches the surface atom with an impact parameter b and scatters at an angle θ, so that it passes the next atom at a distance R
24. Figure 1.24. Ratio of the shadow cone radius from the screened potential R_M to the unscreened potential R_C as a function of R_C/a (data from [FEL 82])
25. Figure 1.25. Thomas Fermi screening distance as a function of the atomic number of the target nucleus
26. Figure 1.26. Experimental values of the surface peak intensity for various crystals expressed in number of atoms per row as a function of the ratio between the thermal vibration amplitude and the radius of the shadow cone. The continuous curve was generated from numerical simulations (data from [FEL 82])
27. Figure 1.27. Calculated values of the surface peak area for silicon channeled in the [110] direction expressed in the number of atoms per row as a function of the ion beam energy
28. Figure 1.28. Schematic view of shadowing geometries employed to enhance the scattering yields of the initial atomic layers with respect to deeper layers
29. Figure 1.29. Schematic view of the shadowing and blocking effects
30. Figure 1.30. Blocking dip width versus scattered energy for helium ions in silicon along the <110> direction neglecting (straight line) or taking into account (dotted line) the thermal vibration amplitude at 300 K
31. Figure 1.31. Blocking dip width versus scattered energy for protons in silicon along the <110> direction neglecting (straight line) or taking into account (dotted line) the amplitude of thermal vibration at 300 K
32. Figure 1.32. Schematic view of atomic displacements due to elastic strain within a crystal
33. Figure 1.33. Schematic view of the shadowing/blocking geometry used to analyze surface structures (from the Surface Physics Group at the University of York (UK))
34. Figure 1.34. Theoretical response functions for two point sources resolved according to a) the Rayleigh criterion and b) the Gaussian FWHM criterion. In each case, the single central peak is the response when the two point sources are not separated at all
35. Figure 1.35. Simulated RBS spectra for nominally resolved Au delta-doped layers in Si, of equal intensity (a and c) and of ten times different intensities (b and d) and with good (a and b) and poor (c and d) statistics
36. Figure 1.36. Schematic illustration of the particle trajectories in an ion beam of finite emittance
37. Figure 1.37. Maximum beam intensity, as a function the beam diameter for protons of 10, 100 and 1000 keV, below which the charge space effect can be neglected (considering a distance between the focusing lens and the sample of 1 m)
38. Figure 1.38. Time to displace 10% of the silicon atoms in the first 10 nm with a 10 nA helium ion beam of 100 keV and 1 MeV respectively according to SRIM calculations [ZIE 04]
39. Figure 1.39. Schematic illustration of the particle trajectories in a continuous layer (left) and in a set of 3D objects (right)
40. Figure 1.40. 2D map of scattered ion intensities as a function of the scattering angle and scattered ion energy for normal incidence of 100 keV He⁺ ions calculated for a 2D layer (top left) or for three nanoparticle shapes: sphere (top right), hemisphere (bottom left) and cylinder (bottom right) [SOR 09]
2 Instruments and Methods
1. Figure 2.1. Schematic drawings of electrostatic accelerator operation. Left: Van de Graaff principle. Right: voltage multiplier principle. s: ion source. t: accelerator tube. HVT: high voltage terminal. v: voltage multiplying stack. m: belt motor. a: alternator. DC HV: dc belt charge high voltage supply. AC RF: ac high frequency power supply
2. Figure 2.2. Schematic diagram of an electrostatic analyzer
3. Figure 2.3. Schematic diagram of a magnetic sector analyzer
4. Figure 2.4. A typical standard RBS sample analysis chamber. c: collimator; ic: insulated vacuum coupling; ci: current integrator; ift: insulated feedthrough; pa: preamplifier; d: particle detector; sh: sample holder; sm: stepper motor; ca: control and acquisition interface; acq: data acquisition computer; con: control computer
5. Figure 2.5. Top: typical experimental geometry for standard RBS measurements. Bottom: simulated RBS spectra obtained from a series of SrO thin films of increasing thickness on a Si substrate. For this simulation, a detector resolution of 15 keV was used, and the incident ⁴He⁺ beam energy is 2.0 MeV
6. Figure 2.6. Top: typical grazing geometry used to optimize depth resolution in standard RBS. Bottom: Simulated spectra of SrO layers of increasing thickness obtained in the grazing incidence indicated for a beam energy of 0.8 MeV ⁴He⁺, and a detector resolution of 15 keV
7. Figure 2.7. Illustration of how angular multiple scattering can degrade effective depth resolution for highly grazing incident beam geometries
8. Figure 2.8. Schematic diagram of a MEIS experiment
9. Figure 2.9. MEIS simulated spectra for increasing thicknesses of SrO on Si, obtained with an electrostatic detector typically used in MEIS, with energy resolution ΔE/E of 3 × 10⁻³, and an incident beam of 400 keV ⁴He⁺
10. Figure 2.10. Top: typical experimental geometry for ERDA measurements of hydrogen isotopes in thin films. Bottom: Simulated spectra for SrO films of increasing thickness, charged with equal parts of hydrogen and deuterium, on a Si substrate. For this simulation, the incident ⁴He⁺ energy was 2.0 MeV, and a 9 µm Mylar film was sufficient to stop the ⁴He⁺ elastically scattered from the Si and Sr in the sample
11. Figure 2.11. The cross-section of the ¹⁸O(p,α)¹⁵N nuclear reaction [LOR 79]. The very narrow resonance at 151 keV (magnitude multiplied by 10 so as to be visible on the graph) has been widely used for Narrow Resonance Profiling of ¹⁸O
12. Figure 2.12. Top: typical experimental geometry used for NRP with the ¹⁸O(p,α)15 N reaction. Note that since the detection energy resolution does not affect depth resolution, a large detector may be used. The poor energy resolution (some tens of keV), the energy straggling in the mylar film, and the large kinematic spread in such an arrangement have no influence on the obtainable depth resolution. Bottom: Simulated NRP excitation curves obtained from the 151 keV resonance in ¹⁸O(p,α)15 N in Sr¹⁸O films of varying thicknesses
3 Applications
1. Figure 3.1. RBS spectra obtained from a thin SiO₂ film on Si with the incident beam channeled along the (110) silicon axis, and detection in grazing (a) and standard (b) geometries [FEL 78]
2. Figure 3.2. Yield of non-crystalline Si from (110) channeled spectra on SiO₂ layers of increasing thickness on Si [FEL 78]. The slope and intercept of the line indicate that in the region of the interface, 2.5 × 10¹⁵ Si atoms cm⁻² are either in non-stoichiometric oxide or in a disturbed region of the Si
3. Figure 3.3. Illustration of the principle of a simple isotopic tracing experiment. Silicon is oxidized first in ¹⁶O₂ and then in ¹⁸O₂. The position of the ¹⁸O in the oxide gives information about the oxygen exchange, transport and oxide growth processes. In the case illustrated here, oxygen exchange and network diffusion occur without growth in the surface region, whereas oxide growth occurs through interstitial transport of O₂ molecules to the SiO₂/Si interface, where oxidation of the silicon occurs
4. Figure 3.4. (a) Measured (points) and calculated (lines) excitation curves of 18_O in SiO₂/SiC annealed in ¹⁸O₂. The calculated excitation curve corresponds to the concentration profiles in (b)
5. Figure 3.5. (reproduced from Ganem, 2011 [GAN 11], and based on Trimaille, 1994 [TRI 94]). A 20 nm thick thermal oxide of natural isotopic composition is further oxidized (900°C, 5 h, 100 mbar) in pure dry ¹⁸O₂. The solid line is the excitation curve calculated for the assumed concentration profile of ¹⁸O shown in the inset
6. Figure 3.6. Schematic representation of a silicon carbide crystal. The c-axis is vertical in the figure, with the carbon face perpendicular to (0001) and the Si face perpendicular to by convention. Along the c-axis, the Si and C atoms are separated by just 0.063 nm (and the Si–C bilayers are separated by 0.189 nm)
7. Figure 3.7. (a) Measured (points) and calculated (lines) NRP excitation curves about the 151 keV resonance in ¹⁸O(p,α)¹⁵N after ¹⁶O/¹⁸O oxidations of Si (open points, dashed lines) and SiC (solid points, full lines). The calculated excitation curves correspond to the concentration profiles in (b)
8. Figure 3.8. Thermal oxides of different thicknesses are formed on Si and SiC by two different means, so as to be able to vary the oxide thickness and the nature of the SiO₂/semiconductor independently. In (a), an oxide of around 50 nm is first grown on all samples and then etched chemically for various times so as to produce a system in which the SiO₂/SC interface is identical for all SiC or Si samples, and the overlying thermal oxide thickness varies. In (b), oxide thicknesses of the same range are produced by thermally oxidizing for suitable times, so that in this case the nature of the SiO₂/SC interface varies. From [VIC 02]
9. Figure 3.9. (Top) SEM image of SiC nanocrystals below the SiO₂/Si interface after chemical removal of the overlying SiO₂. (Bottom) TEM image of a cross-section of one such nanocrystal. The SiC is epitaxial with the Si, but has a lattice parameter about 20% larger than that of Si. The visible periodic contrast is a moiré pattern between the SiC nanocrystal and single-crystal silicon lying beneath it in the TEM cross-section. Images from [PÉC 07]
10. Figure 3.10. From Deville-Cavellin, 2009 [DEV 09]. (a) Measured (points) and calculated (lines) excitation curves of ¹⁸O in SiO₂/Si annealed in ¹³C¹⁸O. The calculated excitation curve corresponds to the concentration profiles in (b). The diffusion and exchange can be divided into three independent processes (see text)
11. Figure 3.11. Measured amounts of interface ¹³C and ¹⁸O after 90 min annealing of SiO₂/Si in ¹³C¹⁸O atmosphere at 1,100°C at various pressures and for various initial oxide thicknesses
12. Figure 3.12. Examples of non-random RBS spectra. (Top spectrum) the ion beam alignment is too close to an axial channeling direction. (Bottom Spectrum) the ion beam alignment is too close to a planar channeling orientation
13. Figure 3.13. In-plane lattice parameters, band gaps and corresponding wavelengths for different families of semiconductors. For a color version of this figure, see www.iste.co.uk/jalabert/ionbeam.zip
14. Figure 3.14. Measured (dots) and simulated (solid line) RBS spectra of an AlGaInN layer deposited on GaN/sapphire at a substrate temperature of 630°C. The surface channels are marked by the corresponding element [MON 03b]
15. Figure 3.15. Measured and simulated (solid line) RBS spectrum of an Al_0.44Ga_0.55In_0.01N sample grown on GaN/sapphire at a substrate temperature of 650°C. The inset shows details of the indium peak at the sample surface [MON 03b]
16. Figure 3.16. Illustration of the method used to measure a small amount of material by comparing the measurement and simulation. On the top, the peak area is calculated using the experimental spectrum. On the bottom, the same calculation is done using the simulated spectrum
17. Figure 3.17. Maximum indium incorporation in the quaternary compound as a function of the Al mole fraction and the substrate temperature [MON 03a]
18. Figure 3.18. RBS spectrum of a sample containing a Tm-doped GaN layer (104 nm) covered by a Tm-doped AlN layer (180 nm) [AND 05]. The concentration of Tm in GaN is 1.2%. The letters are used to mark the positions of the elements: A is N in AlN, GaN: Tm and AlN:Tm, B is Al in the AlN substrate, C is Al in AlN:Tm, D is Ga in GaN:Tm and E is Tm in GaN:Tm. The arrow with the letter F indicates the position of Tm on the surface of the AlN
19. Figure 3.19. Normalized growth speeds of GaN layers doped with europium as a function of the concentration of Eu [HOR 04a]. The squares correspond to growth under Ga-rich conditions and the circles to growth under N-rich conditions. The inset shows a typical RBS spectrum corresponding to a multilayer AlN/GaN/AlN/GaN:Eu/AIN
20. Figure 3.20. RHEED diffraction pattern (left) and AFM image (right) of a plane of GaN quantum dots
21. Figure 3.21. High-resolution transmission electron microscopy (HRTEM) image of two GaN quantum dots. The top dot is deposited on the AlN surface and the bottom one is embedded in AlN
22. Figure 3.22. Measured (open circles) and calculated (solid line) RBS spectra of a sample containing two GaN quantum wells of nominal thicknesses 20 Å. The thicknesses of the quantum well buried in AlN and the layer deposited on surface are, respectively, 16.7 and 19.6 Å. The substrate temperature was set at 750 °C
23. Figure 3.23. Variation of the thinning of GaN quantum wells encapsulated in a matrix of AlN as a function of the nominal thickness of the well. The substrate temperature was set at 750°C for growth of the two layers
24. Figure 3.24. Variation of the thickness reduction of GaN quantum wells with a nominal thickness of 50 Å buried in AlN as a function of the encapsulating temperature. The substrate temperature was set at 750°C for the growth of GaN wells
25. Figure 3.25. High-resolution TEM images of two GaN quantum wells of nominal thickness 20 Å, encapsulated in an AlN layer deposited, respectively, at (a) 750 °C and (b) 700 °C as well as the profiles of corresponding inter-planar distances. The thickness of the wells encapsulated at 750 °C varies from 12.5 to 17.5 Å. However, the thickness of the wells encapsulated at 700 °C remains constant and equals 20 Å
26. Figure 3.26. High-resolution TEM image of a GaN quantum well encapsulated in a matrix of AlN grown at 750 °C. The observed GaN thickness varies from 17.5 ± 1.2 to 12.5 ± 1.2 Å. The lower GaN/AlN interface seems relatively more regular, flat and uniform than the upper AlN/GaN interface
27. Figure 3.27. RBS spectra measured (open circles) and calculated (solid line) of a sample containing three identical GaN quantum wells of nominal thickness 50 Å covered by an Al flux before encapsulation. Al flux was high enough to completely cover the surface of GaN. The QW1, QW2 and QW3 wells are coated with Al for 1, 10 and 30 min, respectively. The substrate temperature was set at 750°C
28. Figure 3.28. Measured (open circles) and calculated (solid line) RBS spectra of a sample containing two identical planes of GaN quantum dots, of nominal thickness 18 Å, which are, in one case, buried in AlN and, in the other, deposited on the surface. The substrate temperature was set at 750 °C
29. Figure 3.29. Variation in the thickness reduction of GaN quantum dot planes deposited on and encapsulated in AlN at 750°C as a function of the amount of GaN nominally deposited
30. Figure 3.30. HRTEM image of a superlattice of quantum dots GaN/AlN deposited at 730 °C. If the layers of AlN between dot planes are thick enough, a smooth upper AlN interface is observed. However, if the layer is very thin (~20 Å), the roughness induced by the layer of GaN dots is propagated to the upper AlN interface
31. Figure 3.31. HRTEM image of the wetting layer connecting the GaN islands deposited on AlN and encapsulated in an AlN matrix at 750 °C as well as the corresponding interplanar distance profile. A quantum dot is visible on the right side of the image. The thickness of the wetting layer has been reduced to about 2.5 Å, that is, a single monolayer
32. Figure 3.32. Change in total free surface area of a plane of GaN quantum dots as well as the respective (0001) and surfaces as a function of the amount of GaN nominally deposited. The surface areas were calculated from AFM data [GOG 03]
33. Figure 3.33. a) Amount of material contained in the GaN islands as a function of the nominal amount of GaN deposited. The solid line corresponds to the amount of material involved in the formation of the dots, assuming a wetting layer of constant thickness equal to two monolayers. b) Variation of the thickness of the wetting layer of GaN depending on the nominal amount of GaN deposited deduced from curve (a) [GOG 03]
34. Figure 3.34. Physical structure of an n-type MOSFET: a) perspective view and b) cross-section, showing the characteristic dimensions W and L; the contacts S, G and D and the regions are composed of oxide (dielectric film) and of bulk silicon (substrate) [SED 04]
35. Figure 3.35. Electron microscopy images showing the evolution of MOSFETs produced by Intel Corporation. a) and b) are the first and second transistor generations strained by a SiGe alloy. c) and d) the first and second transistor generations fabricated with a high-permittivity dielectric barrier (high-κ). e) Implementation of the first transistors in three dimensions (3D). The length L of the channel is displayed on top of each image with the year of manufacture [BOH 11]
36. Figure 3.36. Experimental MEIS energy spectrum of a HfO₂/SiO₂/Si (100) stack grown at 430°C. The inset illustrates the scattering geometry: the 101.5 keV He⁺ incident ion beam is aligned along the [111] axis of Si substrate and the scattered ions along the [211] direction
37. Figure 3.37. High-resolution transmission electron microscope image of HfO₂/SiO₂/Si stack deposited at a) 430 °C and b) 550 °C
38. Figure 3.38. MEIS spectra of Hf atoms for the HfO₂ layer grown at 430°C: The circles are the experimental results, and the solid line is the simulation for pure HfO₂. a) Calculated spectra considering the presence of 0.5 nm (short dashed line), 1.0 nm (dashed line) and 1.5 nm (dotted line) of silicate. b) Calculated spectra considering an rms roughness of 0.25 nm (dotted line), 0.5 nm (dashed line) and 1 nm (short dashed line) of the HfO₂/SiO₂ interface
39. Figure 3.39. MEIS spectrum of Hf atoms for the HfO₂ layer grown at 430 °C. Experimental results (circles), simulation for pure HfO₂ (dashed line) and calculated spectrum considering the presence of both 0.5 nm silicate and 0.25 nm rms roughness (solid line) at the HfO₂/SiO₂ interface
40. Figure 3.40. Backscattering spectrum obtained in a channeling alignment for as-deposited Hf₀_.67Si_0.33O₂/SiO_xN_y/Si (001) film
41. Figure 3.41. Variation of ¹⁸O and ¹⁶O peaks for the a) HfO₂/SiO₂/Si (001) and b) Hf_0.67Si_0.33O₂/SiO_xN_y/Si (001) films with re-oxidation time. c) Oxygen exchange kinetics curves in hafnium oxide (open symbols) and hafnium silicate (dark symbols) films
42. Figure 3.42. Schematic representation of MEIS spectra for Si, ¹⁸O and ¹⁶O energy range of isotopic exchange and incorporation in hafnium silicate film corresponding to as-deposited film, re-oxidized for 30 min at 763, 973 and 1,223 K
43. Figure 3.43. Variation of oxygen density in a) hafnium silicate layer and b) interfacial SiO_xN_y layer as a function of re-oxidation temperature during 30 min annealing in 10⁻² Torr of ¹⁸O₂
44. Figure 3.44. Semi-logarithmic dependence of the amount of oxygen atoms incorporated near SiON interface of Hf_0.67Si_0.33O₂/SiO_xN_y (10⁻² Torr, 30 min), SiO_xN_y and SiO₂ (7 Torr, 60 min) films versus inverse temperature after re-oxidation in ¹⁸O₂
45. Figure 3.45. Composition depth profiles of HfO₂/SiON/Si (001) derived from the HR-ERD analysis (thin lines). The result of HRBS is also shown for a comparison (thick lines)
46. Figure 3.46. TEM micrograph of 45 nm thick nanolaminate, with individual Al₂O₃ and TiO₂ layer thicknesses of 2 and 3 nm, respectively
47. Figure 3.47. Al2O3 (10 nm)/TiO₂ (10 nm) nanolaminate measured with 9.9 MeV ³⁵Cl⁵+ at 84° incident angle. a) A histogram of the raw spectra is shown, and b) the corresponding elemental depth profiles. Total concentration for each depth is scaled to 100 at. % [LAI 11]
48. Figure 3.48. Cross-section of an npn (left) and a pnp (right) CMOS transistor
49. Figure 3.49. MEIS spectra showing the growth of the Si damage and As dopant yield as a function of fluence for 2.5 keV As⁺ ion implantation into virgin Si at room temperature [WER 04]
50. Figure 3.50. Depth profiles of displaced Si and As implanted atoms obtained from the MEIS spectra in Figure 3.49. SRIM calculated Si vacancy and recoil distributions and the As implant profile are shown for comparison. The dependent peak position of the As implant is indicated by arrows
51. Figure 3.51. MEIS spectra of 2.5 keV As⁺ ions as implanted into Si (100) to a dose of 1.5 × 10¹⁵ atoms cm⁻² at 25 °C and following 20 s RTA at 500, 600 and 900 °C. Virgin and random Si spectra are shown for comparison [VAN 02]
52. Figure 3.52. MEIS spectra of 2.5 keV As⁺ ions as implanted into Si (100) to a dose of 1.5 × 10¹⁵ ions cm⁻² at implant temperatures of −120, 25 and 300 °C. The virgin Si spectrum is shown for comparison
53. Figure 3.53. Diagram illustrating the geometry used in blocking experiments. The trajectory of the ion after the impact is not perfectly aligned with the crystallographic direction. In fact, the difference between the angular position of the blocking dip observed by the detector and the orientation of the atomic column in the crystal is 0.012° in the case of a 100 keV proton scattering from Si at 90°
54. Figure 3.54. Typical geometry of an ion-scattering experience. The ion energies at points d and d’ depend on the respective kinematic factors calculated for scattering angles θ_sc and θ’_sc and the energy losses along the output paths cd and cd’
55. Figure 3.55. Calculation of the energy distribution of 199 keV helium ions scattered by a sample of pure germanium from: a) the surface, b) a depth of 10 nm and c) a depth of 20 nm. The incident beam is aligned on the normal to the sample surface
56. Figure 3.56. Illustration of the geometric transformation applied to the “silicon” part of an MEIS 2D spectrum corresponding to a Si/SiGe/Si stack. (Left) The original 2D MEIS spectrum and (right) the corrected picture in the region of the data corresponding to silicon
57. Figure 3.57. Diagram of the scattering geometry in the plane selected for MEIS experiments
58. Figure 3.58. Artist’s view of the elastic relaxation of a quantum dot biaxially strained by its substrate
59. Figure 3.59. Left: Experimental MEIS spectrum of a non-encapsulated GaN quantum dot plane around the blocking direction. Right: Angular MEIS spectra of these unencapsulated GaN quantum dots taken at different energies ranging from 96,530 eV (GaN surface of the dots) to 94,339 eV (GaN/AlN interface). The dotted line indicates the position of blocking corresponding to the GaN/AlN interface. One can also note a satellite dip at 126.8° in the angular cut at 96,530 eV, which is associated with the presence of the wetting layer below the dots
60. Figure 3.60. Depth profile of the c/a ratio in: a) one plane of GaN quantum dots on the sample surface, b) one plane of quantum dots encapsulated by 10 monolayers of AlN and c) one plane of quantum dots encapsulated by 20 monolayers of AlN. The dotted line indicates the value of c/a corresponding to a relaxed, unstrained GaN crystal. The open square in Figure 3.60(a) corresponds to the position of the satellite dip at 126.8° observed in Figure 3.59 (at 96,530 eV on the right-hand-side figure), which is assigned to the wetting layer. Horizontal error bars (depth scale) were calculated by taking into account both the energy resolution of the detector and the energy straggling of the incident proton beam
61. Figure 3.61. Two-dimensional contour plots of the lattice parameters a (a) and c (b). The numbers in boxes indicate the values of the parameters (in Å) along the different contour lines. The corresponding contour plot of the ratio c/a is shown in (c), and the solid line in (d) displays the calculated depth profile of the in-plane-averaged c/a. The dotted line indicates the value of c/a corresponding to relaxed, unstrained GaN and the dashed line is that expected for a two-dimensional GaN layer biaxially strained to AlN
62. Figure 3.62. 0.5 × 0.5 µm² AFM micrographs of a-plane GaN quantum dots at the surface of sample D (a) and sample E (b). On sample E, we can distinguish various shapes: square, rectangle (along [0001] or or trapezoid, pointed, respectively, by arrows 1–4
63. Figure 3.63. Scheme of the scattering geometry in the (0001) a) and (1–100) b) planes for medium-energy ion-scattering experiments
64. Figure 3.64. Energy and angular distributions of the backscattered protons for sample C, close to the blocking direction. Angle 30° corresponds to the same blocking direction in the SiC substrate, which is used as a reference
65. Figure 3.65. Depth profiles of the , (d), (f) ratios for samples A, B and C. The GaN/AlN label refers to a GaN layer completely strained in both in-plane directions on a relaxed AlN layer
66. Figure 3.66. High-resolution cross-sectional TEM image of a GaN/AlN (1.5 nm/3 nm) superlattice taken along the zone axis
67. Figure 3.67. Energy/angular spectrum of He⁺ ions scattered by the gallium atoms from the three upper GaN quantum wells
68. Figure 3.68. Depth profile of the in-plane lattice parameter within one quantum well along the growth direction, extracted from the MEIS measurements
69. Figure 3.69. Variation in the in-plane lattice parameter, measured by RHEED, during the growth of GaN/AlN (1.5 nm/3 nm) quantum wells after attaining steady-state conditions
70. Figure 3.70. a) Magnification of Figure 3.66 showing the interaction of two structural defects at the GaN/AlN interfaces. b) Phase image obtained from image (a) using the geometrical phase analysis method applied to lattice periodicity. The 2π radians variation (full gray-scale range) at the circle positions is characteristic of a dislocation
71. Figure 3.71. Scanning electron micrographs in top (a) and side (b) views of the investigated sample. The well-separated AlN/GaN/AlN/GaN nanowire heterostructures are about 280 nm long and have a diameter of about 30 nm on average. (c) Micrograph taken in transmission, on which GaN appears darker than AlN. The GaN insertion of about 5 nm is embedded in a bottom AlN segment of about 16 nm and top AlN segment of about 3 nm
72. Figure 3.72. Schematic view of nanowires in the MEIS experiment. a) In- and out- trajectories are parallel to the plane, that is, parallel to the NW wall. b) In- and out-trajectories are in a plane rotated by 30° with respect to the plane, that is, parallel to the plane. It is important to note that the maximum energy of Ga-backscattered He⁺ ions is expected to correspond to that of the NW walls
73. Figure 3.73. Schematic illustration of the two scattering geometries in the wurtzite cell: a) The incident ion beam is aligned in the plane, 15.4° from the [0001] direction, and the blocking cone is around the direction. b) The incident ion beam is aligned in the plane, 5.3° from the [0001] direction, and the blocking cone is around the direction
74. Figure 3.74. MEIS energy spectra corresponding to helium ions scattered by the gallium atoms of the nanowires. The scattering plane is parallel to: a) the plane of the hexagonal structure and b) the plane. The selected scattering angles are misaligned with the blocking dip positions by few degrees. The dotted lines correspond to the simulated spectra of bulk GaN, indicating the surface energy of gallium
75. Figure 3.75. MEIS blocking dips as a function of the scattered ion energy in the window corresponding to the Ga contribution to the spectrum. It is important to note a clear shift in the position of the blocking dip in the 92,335–95,568 keV energy range
76. Figure 3.76. Strain profiles extracted from the shifts observed in the blocking dip positions along: a) the direction and b) the direction. The dotted line corresponds to a 2D simulation of a 4.9 nm thick GaN insertion in an AlN matrix with a maximum strain of 2.3%
77. Figure 3.77. Plot of the calculated strain along the axis of a nanowire
78. Figure 3.78. MEIS spectrum acquired around the blocking direction of the substrate. Signals from the different parts of the sample are (1) Ge from the 12 nm thick SiGe layer, (2) Si from the surface native oxide layer, (3) Si from the 2 nm thick Si cap layer, (4) Si from the 12 nm thick SiGe layer, (5) O from the surface native oxide layer and (6) Si from the substrate
79. Figure 3.79. Simulation of the expected MEIS spectrum, assuming an abrupt interface between SiGe and Si
80. Figure 3.80. Strain depth profile in silicon deduced from the MEIS experiment (dots) and simulations computed from elastic theory calculation using the finite-element method including (solid curve) or not (dashed curve) a germanium gradient in the 2 nm thick silicon cap
81. Figure 3.81. Left: Experimental MEIS profile corresponding to the germanium within the sample. The dotted curve is a simulated spectrum of the sample considering an abrupt interface between the alloy and the silicon film, and the solid curve corresponds to the introduction of a germanium gradient in the surface film, which is, in fact, a SiGe alloy with decreasing germanium content. Right: Gradient of the germanium composition used to fit the experimental result on the left
82. Figure 3.82. STM images of Ge three-dimensional islands on a Si (113) substrate before or after several annealing steps: a) nanowires after deposition of 6.2 monolayers of Ge at 430 °C; b) elongated islands after annealing at 430 °C for 25 s; c) after further annealing at 430 °C for 5 min; d) dot-like islands after annealing at 500 °C for 5 min. The four images are all 500 × 500 nm² in scan area [SUM 02]
83. Figure 3.83. MEIS energy spectra from the seven and four Ge monolayers deposited on the Si (113) surface
84. Figure 3.84. Blocking profile for Ge nanowires measured in the plane; that for the Si substrate is shown for reference
85. Figure 3.85. Blocking profile for Ge nanowires measured in the plane; that for the Si substrate is shown for reference
86. Figure 3.86. Schematic illustration of strain along and across the nanowires
87. Figure 3.87. AFM images of a) pyramid-shaped Ge nanostructures in a 5.5 monolayer thick layer grown at 500 °C on Si (001) and b) dome-shaped nanostructures in an 8.9 monolayer thick Ge layer grown at 600 °C. Typical line profiles are shown in the insets
88. Figure 3.88. MEIS blocking dips as a function of depth through the Ge layer with dome-shaped islands corresponding to Figure 3.87(b)
89. Figure 3.89. Shifts in MEIS blocking dips and strain depth profiles through Ge/Si (001) layers whose surfaces consist of Ge wetting layers, Ge pyramids and Ge domes. Typical Ge and Si blocking dips for pyramid structures and the bulk Si substrate are shown in the inset
90. Figure 3.90. Two-dimensional blocking pattern for uranium ions elastically scattered in silicon [GOL 99]. In the inset, the one-dimensional blocking pattern integrated on the azimuthal angles from the center of the axial dip is presented. The full line is the result of a Monte Carlo simulation
91. Figure 3.91. 2D angular map of He⁺ ions scattered by the germanium atoms in a SiGe layer at a depth of 18 nm below surface
92. Figure 3.92. Stereographic projection of a face-centered cubic crystal on the [100] direction [NOA 03]. The gray area corresponds to the experimental map shown in Figure 3.91. The relation between the scattering angle θ_sc and the polar angle θ_pol of the figure is θ_sc = 180 − θ_inc − θ_pol
93. Figure 3.93. Time-of-flight spectra of He⁺ particles scattered from the Er silicide and the Si (001) substrate. Spectra A and B were obtained at the different scattering angles. The spectra in the flight time ranges of 681–689 ns and 700–760 ns correspond to Er and Si atoms, respectively
94. Figure 3.94. Intensity distribution of He⁺ particles scattered around Si (100) plane. a) Scattering by Si atoms at the depth of 16–60 nm in the substrate. b) Scattering by Er atoms
95. Figure 3.95. Schematic diagram of the Er atomic arrangement suspected to give the blocking cones as observed in Figure 3.94 in a plane parallel to Si (100)
4 The Place of NanoIBA in the Characterization Forest
1. Figure 4.1. Diagram of the basic principle of physical and chemical characterization
2. Figure 4.2. General diagram of a SIMS experiment
3. Figure 4.3. SIMS depth profiling on CMOS gate stacks (40 nm WSi; 10 nm HfO₂, 2 nm SiO₂ on Si substrate) using MCs₂⁺ analysis mode: a) Si profiles and b) F profiles as a function of annealing temperature. F contamination comes from the precursor (WF₆) used for WSi_x layer deposition
4. Figure 4.4. N and O content by NRA (primary ions: ~ 900-keV deuterons) in the WN_x layer of two gate stacks: a) WN_x (40nm)/HfO₂ (4 nm) on an Si substrate; b) WN_x (40 nm)/SiO₂ (2 nm) on an Si substrate. Effect of a 1,000 °C annealing for 10s
5. Figure 4.5. MEIS analysis (He⁺, 100 keV) of a ZrO₂/HfO₂ bilayer before (solid squares) and after (open squares) annealing: 2.5 nm ZrO₂/1.3 nm HfO₂/1.2 nm SiO₂ on an Si substrate. The dots represent experimental results and the lines, the simulation results [LHO 08]
6. Figure 4.6. APT on a CMOS metal gate stack – TiN (6.6 nm)/LaO_x (0.4 nm)/HfSiO_x (1.7 nm)/SiO₂ (1 nm)/Si substrate: a) as-deposited; b) after annealing at 1,065 °C (courtesy of Adeline Grenier, CEA-Leti)
7. Figure 4.7. Front-side and back-side simulated MEIS spectra in the Hf/La area, with a 200-keV He⁺ primary beam incident at 21°, and a 131° detection angle in a TiN (6.5 nm)/La₂O₃ (0.4 nm)/HfSiON (1.7 nm)/SiON (1.5 nm) stack on an Si substrate. The simulation was made with homemade software, taking into account straggling and neutralization effects. Hf peak intensities were aligned in energy to allow better visualization of the differences between the two approaches in terms of peak separation power, after [PY 11]
8. Figure 4.8. HAXPS Si 1s core-level spectra obtained on a CMOS metal gate stack containing La: a) as-deposited and b) spike-annealed samples (1,065 °C). The as-deposited sample is the same stack as in Figure 4.7
9. Figure 4.9. Experimental and fitted back-side MEIS spectra of a TiN (6.5 nm)/LaO_x (0.4 nm)/HfSiON (1.7 nm)/SiON (1.5 nm) stack on an Si substrate for as-deposited and annealed samples
10. Figure 4.10. XRD Omega–2 Theta scans around the (004) Si diffraction order using a high-resolution XRD (X’Pert MRD fro Philips) system at a Cu K_α₁ wavelength of 1.5406 Å on Si₁₋_yC_y layers on a (001)-oriented Si substrate for variable y carbon concentration. The carbon concentration is extracted from the Si₁₋_yC_y diffraction peak angular position assuming a pseudomorphic growth and not a relaxed layer
11. Figure 4.11. RBS spectra of a TiN (10 nm)/ULK (300 nm) stack on a silicon substrate before and after different He⁺ plasma treatments showing the effect on the limitation of the Ti diffusion in the ULK layer through pore sealing: (black squares) before plasma treatment; (gray triangles) after plasma treatment; (black triangles) reference TiN/SiO₂/Si stack
12. Figure 4.12. EELS-TEM on Cu interconnection lines for control of the Ti diffusion into the dielectric at the device level: a) Ti map on a cross-section of Cu lines with 10-nm-thick TiN diffusion barriers and ULK dielectric lines; Ti profiles through cross-sections of Cu lines with 10-nm-thick TiN diffusion barriers and b) SiO₂ dielectric lines, c) ULK dielectric lines without pore sealing and d) ULK dielectric lines with an SiC liner
13. Figure 4.13. Diagram of a GIFAD experiment, after [KHE 09]
14. Figure 4.14. GIFAD diffraction images on the c(2 × 2) reconstructed surface of a (001)-oriented ZnSe epilayer grown by MBE on a (001)-oriented GaAs substrate obtained with 400-eV He⁺ beam, for the [ıī0], [ıı0] and [ı00] directions (the narrow spot on the lower part is the direct beam), after [KHE 09]
15. Figure 4.15. Corrugation functions derived from the fit to the experimental data of Figure 4.14. Y and d are respectively the coordinate and the period along the transverse direction. Projected atomic positions are given in the lower part; large and small filled circles are Zn and Se atoms respectively, after [KHE 09]

Swift Ion Beam Analysis in Nanosciences

Preamble
Rutherford and IBA