This book deals with the subject of secondary energy spectroscopy in the scanning electron microscope (SEM). The SEM is a widely used research instrument for scientific and engineering research and its low energy scattered electrons, known as secondary electrons, are used mainly for the purpose of nanoscale topographic imaging. This book demonstrates the advantages of carrying out precision electron energy spectroscopy of its secondary electrons, in addition to them being used for imaging. The book will demonstrate how secondary electron energy spectroscopy can transform the SEM into a powerful analytical tool that can map valuable material science information to the nanoscale, superimposing it onto the instrument's normal topographic mode imaging. The book demonstrates how the SEM can then be used to quantify/identify materials, acquire bulk density of states information, capture dopant density distributions in semiconductor specimens, and map surface charge distributions.
Author(s): Anjam Khursheed
Publisher: World Scientific Publishing
Year: 2020
Language: English
Pages: 343
City: Singapore
Contents
1. SE Energy Spectrometer Design
1.1 The first SEM SE energy spectrometer proposal
1.2 Voltage contrast spectrometers
1.3 In-lens multi-channel position sensitive SE energy analyzer designs
1.4 Retarding field energy analyzer attachments
1.5 Energy filtered SEM SE detector systems
1.6 Band-pass electric toroidal sector spectrometer attachments
2. The Wide-angle Toroidal Energy Analyzer Attachment
2.1 The experimental setup and modes of operation
2.2 Analyzer energy resolution and shot-noise considerations
2.3 Comparison of experimental SE energy spectra to theoretical analytical energy distributions
2.4 Surface field effects and voltage contrast
3. Quantitative Material Contrast
3.1 Quantitative material contrast using SE energy spectral peak shape for elemental metal samples
3.2 Enhanced material contrast through tracking gradient variations in the spectral signal rising edge
3.3 Material contrast through full-range energy spectra
3.4 Quantitative material contrast mapping for close atomic numbers
3.5 Detection of the Auger hydrocarbon contamination peak in the SEM
3.6 Mitigating contamination effects by spectral background normalization
3.7 Gallium ion beam generated SE energy spectra for metals
3.8 SE spectral fine features and the bulk density of states
4. Dopant Profiling and Semiconductor Characterization
4.1 Doped stripe test samples
4.2 SE energy spectral signal shape dependence on probing position, primary beam voltage, and native oxide thickness
4.3 Dopant contrast measurements from p-stripes of different concentrations
4.4 In-situ estimate of native oxide thickness and surface band-bending energy
4.5 Contamination effects
4.6 Lateral dopant profiling across doped stripe edges
4.7 Dopant concentration measurements of bulk doped silicon wafer samples
4.8 Solar cell dopant profiling
4.9 Dopant mapping of intrinsic silicon irradiated by a gallium ion beam
5. Probing and Mapping Charge Distributions
5.1 Monitoring localized charging inmetal-in sulator-semiconductor (MIS) samples
5.2 Probing and analyzing buried charge at multifunctional oxide interfaces
6. Conclusions and Future Work
6.1 Conclusions
6.2 Future SE energy spectral experiments
6.3 Future instrument improvements
Appendix 1 The Electric Radial Mirror Analyser (RMA) Attachment Design
Appendix 2 The Parallel Radial Mirror Analyser (PRMA) Attachment Design
Appendix 3 TCAD Simulation of Test Semiconductor Samples with p-doped Stripes in n-substrate
Bibliography
Index
