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One of the main challenges for semiconductor devicemetrology is the structural and elemental analysis at device dimensions.Advanced semiconductor devices are heterogeneous, three-dimensional, nanometerscale structures. Their gate stacks consist of non-planar layers some of whichhave a sub-nanometer thickness. As a result metrology capable of analyzingthese structures, in particular their interfaces, requires three-dimensionalelemental mapping on a sub-nanometer and hence near atomic scale.In this project we evaluate laser assisted Atom ProbeTomography and Field Ion Microscopy as a potential technique to fulfill theserequirements. Atom Probe Tomography is based on removing or evaporating ionizedatoms from a needle shaped specimen onto a position-sensitive single iondetector. Therefore, a voltage of several kilovolt is applied to a needle withan end radius of a few 10 nanometer creating an electric field of sever 10volts per nanometer at the surface. The electric field lowers the barrier forionizing surface atoms. A laser pulse illuminating the tip can then be used toraise the surface temperature such that on average less than one atom getsionized per impinging pulse. The ion is repelled from the surface by theelectric field and projected onto the detector. The projection is in principleaccurate enough to reconstruct the position of the evaporated atom withsub-nanometer precision. Hence, given a precise reconstruction of the acquireddata, it is possible to reconstruct the analyzed volume on a near atomic scalein three dimensions.In this work we will show that laser assisted Atom ProbeTomography and Field Ion Microscopy are indeed capable of analyzingthree-dimensional structures in semiconductor materials on a near atomic scale- unfortunately, only in very specific cases. We will show throughout this workthat is accuracy is mainly limited by the shape the needle surface acquiresunder the action of the laser, the electric field and the materials exposed onthis surface. The technique only allows for atomic resolution when the shape ofthis surface is well known and ``smooth''. This is usually the case forhomogeneous materials with small number of impurities were the surface willform a near hemispherical cap. When analyzing heterogeneous device structureshowever, the surface adopts a significantly more complex shape as the energynecessary to remove atoms from the surface depends on the nature of the atomexposed at the surface and its chemical bonds. Our limited knowledge of theresulting surface shape strongly limits the precision of the data reconstructionas we will show by analyzing test structures and comparing Atom ProbeTomography results to alternative analysis techniques. We can demonstrate thatheterogeneous structures cause inaccuracies on the nanometer-scale in thereconstructed data sets.The results found in this project highlight that an in depthunderstanding of the formation of the needle surface under the action of thelaser, the electric field and the exposed atomic structure is vital to developAtom Probe Tomography to the maximum. However, our results unfortunately alsoindicate that interfaces exposed at the surface may cause the surface to adopta shape where ions adjacent to the interface are evaporated onto overlappingtrajectories. To the best of my understanding, these overlapping trajectorieswill ultimately limit the resolution achievable with Atom Probe Tomography andour measurements indicate that in some cases the resulting inaccuracies arestill on the order of a nanometer. Hence, while laser assisted Atom ProbeTomography to date provides three-dimensional elemental mapping ofsemiconductors which is by most measures far superior to other availablemethods, it seems to me that it is not capable of three-dimensional atomicscale mapping of advanced semiconductor devices in its current state. 1 Introduction 2 Historical background 2.1 History of the Instrumentation 2.2 Historical contributions to material science 2.3 Conclusions 3 Fundamentals of Field Ion Microscopy and Atom Probe Tomography 21 3.1 Field ionization and adsorption: Interactions of the specimen with an image gas 3.2 Field evaporation and desorption: Removing material from the specimen 3.3 Postionization 3.4 State of the art: Shortcomings of the current theories 3.5 Analysis and data reconstruction 3.5.1 Performing an Atom Probe analysis 3.5.2 Data reconstruction 3.5.3 Example: Reconstructing a Field Ion Microscopy measurement of a silicon tip oriented along the (110) direction 3.6 Conclusions 4 Sample preparation 4.1 Preparation of an Atom Probe Tomography specimen from a wafer 4.2 Specifics for preparing silicon based samples 4.3 Cap layer deposition for Focused Ion Beam based sample preparation 4.3.1 Cap layers for top-down analysis 4.3.2 Cap or supporting layers for cross-section analysis 4.4 Coating of the tip-shaped specimens 4.5 Pick and place methods for Atom Probe Tomography samples of single nanowires 4.6 Conclusions 5 Laser-tip interaction 5.1 Simulation of the laser absorption 5.1.1 Maxwell’s curl Equation in the FDTD algorithm 5.1.2 Electromagnetic fields in frequency and time domain 5.1.3 Absorption of the laser energy 5.1.4 Making pulses shorter 5.2 Simulation of the heat flux and temperature distribution over time 5.3 General results and conclusions 6 Atom Probe Tomography and Field Ion Microscopy on Silicon 6.1 Field Ion Microscopy on Silicon 6.2 Atom Probe Tomography on silicon 6.2.1 Spatial resolution 6.2.2 Mass resolution, noise and sensitivity 6.2.3 Impact of the laser 6.2.4 Influence of other measurement parameters 6.2.5 A note on amorphous and amorphized silicon 6.3 Conclusions 7 Multilayers 7.1 Silicon Silicon-Germanium 7.1.1 Top-down analysis 7.1.2 Cross-section analysis 7.2 Silicon Silicon-Dioxide 7.3 Conclusions 8 Applications 8.1 Introduction 8.2 Direct three-dimensional imaging of Boron clusters in silicon 8.3 Characterization of co-implants for ultra-shallow junctions 8.3.1 Physical characterization of a boron doping profile for ultra shallow junctions 8.3.2 An attempt to characterize the cluster formation inside co- implanted ultra shallow junctions 8.4 Three-dimensional imaging of transistor structures 9 Conclusion and Outlook 9.1 Summary of the project 9.2 Applications for routine Atom Probe Tomography in the semiconductor industry 9.3Envisaged future developments for Atom Probe Tomography Appendix A Atom Probe Tomography on other bulk materials A.1 Germanium A.2 Silicon Carbide 4H A.3 Diamond A.4 Zeolite B Failure mechanisms for silicon-based Atom Probe tips C High depth resolution analysis of Si/SiGe multilayers with the atom probe D Quantitative depth profiling of SiGe-multilayers with the Atom Probe E Characteristics of cross-sectional Atom Probe analysis on semiconductor structures F In-situ observation of non-hemispherical tip shape formation during laser-assisted Atom Probe Tomography G Direct 3D imaging of boron atoms decorating defect loops in ion-implanted silicon nrpages: 360 status: published