Spectroscopic Techniques for Semiconductor Industry

Description

The unique compendium presents special principles and techniques of spectroscopic measurements that are used in semiconductor manufacturing.Since industrial applications of spectroscopy are significantly different from those traditionally used in scientific laboratories, the design concepts and characteristics of industrial spectroscopic devices may vary significantly from conventional systems. These peculiarities are thus succinctly summarized in this volume for a wide audience of students, engineers, and scientific workers.Exceptionally well-illustrated with practical solutions in detail, this useful reference text will open new horizons in new research areas. Contents Preface About the Author 1. Basics of Grating Spectrometers 1.1. Typical Schemes 1.2. Diffraction Grating Formula 1.3. Spectral Resolution 1.4. Spectral Orders 1.5. Order-Sorting Filters 1.6. The Rowland Circle 1.7. Calibration Techniques and Formulas 1.8. Photodetectors 1.9. Thermo-electrical Cooling 1.10. Coupling to Optical Fibers 1.11. Typical Industrial Spectrometers 1.12. Monochromators Supplemental Reading 2. Basics of Fourier-Transform Spectrometers 2.1. Theoretical Background 2.2. Absorption-Type Fourier-Transform Spectrometers 2.3. Emission-Type Fourier-Transform Spectrometers 2.4. Fourier-Transform Reflectometers 2.4.1. Infrared Fourier-transform reflectometers 2.4.2. Combined IR–VIS reflectometer Supplemental Reading 3. High-Resolution Spectroscopy 3.1. Scanning Interferometers Fabry–Perot 3.1.1. Scanning interferometers Fabry-Perot with flat mirrors 3.1.2. Confocal scanning interferometers Fabry-Perot 3.1.3. Practical results 3.2. Laser Heterodyne Spectroscopy 3.2.1. Interference of optical waves on the photodetector 3.2.2. Basic concept of heterodyne spectroscopy 3.2.3. Optimal conditions for wavefronts 3.2.4. Practical schemes of wavefront matching Supplemental Reading 4. Imaging Spectrometers 4.1. One-Dimensional Imaging Spectrometers 4.1.1. Lens-based optical scheme 4.1.2. Typical performance 4.2. Two-Dimensional Imaging Spectrometers 4.2.1. Basic considerations for the Michelson interferometer 4.2.2. Basic properties of CCR 4.2.3. Imaging configuration of the Michelson interferometer with CCR 4.2.4. Design concept of the IFS 4.2.5. Data acquisition and processing 4.2.6. Typical performance 4.2.7. Sensitivity Supplemental Reading 5. Gated Intensified Spectrometers 5.1. The Principle and Characteristics of Image Intensifiers 5.2. Sensitivity and Noise 5.3. Additional Advantages of Image Intensifiers 5.4. Coupling Image Intensifier to a Sensor 5.5. Typical Performance of a Gated Intensified Spectrometer 5.5.1. Spectral performance 5.5.2. Computer-enhanced spectral resolution 5.5.3. Gating capabilities 5.5.4. Time-resolved fluorescence spectroscopy 5.5.5. Modulation-sensitive spectroscopy 5.5.6. Enhanced sensitivity spectroscopy 5.5.7. Micro-spectroscopy 5.5.8. Laser-induced breakdown spectroscopy 5.6. Automatic Gain Control in Gated Intensified Spectrometers Supplemental Reading 6. Modulation-Sensitive and Frequency-Selective Spectroscopy 6.1. Modulation-Sensitive Fourier-Spectroscopy 6.2. Frequency-Selective Spectroscopy 6.2.1. Principle of operation 6.2.2. Selectivity of modulated spectra 6.2.3. Measurement of decay times 6.3. Spectroscopy of Harmonics 6.3.1. Introduction 6.3.2. Qualitative theory 6.3.3. Experimental installation and measurement 6.3.4. Experimental results 6.3.5. Effect of chamber condition 6.3.6. Measurement of modulation depth Supplemental Reading 7. Optical Diagnostics in Plasma Etching Machines 7.1. Observation Conditions on Plasma Chambers 7.2. Basic Applications 7.2.1. Endpoint detection 7.2.2. Photomultiplier tubes 7.2.3. Interference filters 7.2.4. Subtraction of plasma fluctuations 7.3. Diagnostics of Pulsed Plasma 7.3.1. Plasma ignition sensors 7.3.2. Life time measurements 7.4. Vertical Distribution of Optical Spectra 7.4.1. Optical system 7.4.2. Spectroscopic system 7.4.3. Spectral analysis of the plasma sheath 7.5. Radial Distribution of Optical Emission 7.5.1. Theoretical concept 7.5.2. Simulation 7.5.3. Design concept and experimental results 7.6. Two-Dimensional Sensor for Measuring Spatial Non-uniformity of Plasma 7.6.1. The WDM WLS concept 7.6.2. Theory of measuring plasma density 7.6.3. Electro-mechanical design and experimental results Supplemental Reading 8. Spectral Reflectometry 8.1. Measurement of Thickness of Dielectric Films 8.1.1. Basic phenomenology of spectral reflectometry 8.1.2. Theory of reflection from multiple layers 8.1.3. Experimental techniques 8.2. Patterned Structures 8.2.1. Phenomenology of spectral reflectometry on patterned structures 8.2.2. Theory of reflection from dielectric sub-wavelength patterned structures 8.3. Chemical Mechanical Polishing 8.3.1. Principle of optical control of silicon thickness 8.3.2. Basic phenomenological differences from visible optics 8.3.3. Sinusoidal shape of oscillations 8.3.4. The role of roughness Supplemental Reading 9. Related Non-spectroscopic Techniques 9.1. Angular Reflectometry 9.1.1. The concept of angular reflectometry 9.1.2. Theoretical restrictions 9.1.3. Experimental examples 9.2. Surface Polarimetry 9.2.1. Principle of surface polarimetry 9.2.2. Principle of measuring critical dimension 9.2.3. Experimental results 9.3. Phase-Resolved Heterodyne Microscopy 9.3.1. Principle of heterodyne microscopy 9.3.2. Optical scheme and instrumentation 9.3.3. Qualitative theory 9.3.4. Experimental results 9.3.5. Super-resolution 9.3.6. Dark-field and bright-field modes of operation 9.3.7. Non-patterned anisotropic surfaces 9.3.8. Three-dimensional profiling of opaque and transparent samples 9.4. Optical Arbitrary Waveform Generator 9.4.1. Problem statement 9.4.2. The concept 9.4.3. Variants of practical realization Supplemental Reading Index