Optical Diagnostics for Thin Film Processing

This volume describes the increasing role of in situ optical diagnostics in thin film processing for applications ranging from fundamental science studies to process development to control during manufacturing. The key advantage of optical diagnostics in these applications is that they are usually noninvasive and nonintrusive. Optical probes of the surface, film, wafer, and gas above the wafer are described for many processes, including plasma etching, MBE, MOCVD, and rapid thermal processing. For each optical technique, the underlying principles are presented, modes of experimental implementation are described, and applications of the diagnostic in thin film processing are analyzed, with examples drawn from microelectronics and optoelectronics. Special attention is paid to real-time probing of the surface, to the noninvasive measurement of temperature, and to the use of optical probes for process control.

Optical Diagnostics for Thin Film Processing is unique. No other volume explores the real-time application of optical techniques in all modes of thin film processing. The text can be used by students and those new to the topic as an introduction and review of the subject. It also serves as a comprehensive resource for engineers, technicians, researchers, and scientists already working in the field.

The only volume that comprehensively explores in situ, real-time, optical probes for all types of thin film processingUseful as an introduction to the subject or as a resource handbookCovers a wide range of thin film processes including plasma etching, MBE, MOCVD, and rapid thermal processingExamples emphasize applications in microelectronics and optoelectronicsIntroductory chapter serves as a guide to all optical diagnostics and their applicationsEach chapter presents the underlying principles, experimental implementation, and applications for a specific optical diagnostic

Overview of Optical Diagnostics: Diagnostics vs. Sensors vs. Transducers. Attributes of in Situ Optical Diagnostics. Performance Characteristics of Sensors. The Need for in Situ Diagnostics. Survey of OpticalProbes. Survey of Nonoptical Probes. Thin Film Processes and Their Diagnostics Needs. The Properties of Light:Propagation. Imaging. Polarization Properties of Light. The Structure of Matter: Separation of Electronic and Nuclear Motion. EnergyLevels in Atoms, Molecules, and Ions. Energy Levels in Solids.The Interactions of Light with Matter for Spectroscopy: Dipole Moments and Polarization. Quantum Mechanics of the Interaction of Light with Matter. Spectroscopy. Nonlinear Optical Interactions. Heating by the Probing Laser. Diagnostics Equipment and Methods: Optical Components. Signal Collection and Analysis.Optical Emission Spectroscopy: Mechanisms for Optical Excitation. Instrumentation. Applications in Processing. Plasma Etching. Laser-Induced Fluorescence: Experimental Considerations. Applications. Transmission (Absorption): Experimental Considerations. Gas-Phase Absorption. Transmission through Adsorbates or Thin Films. Transmission through Substrates for Thermometry. Reflection: Optics of Reflection. Reflectometry, Ellipsometry, and Polarimetry. Optical Dielectric Functions. Reflection at an Interface with a Semi Infinite Medium. Interferometry. Photoreflectance. Infrared Reflection-Absorption Spectroscopy. Differential Reflectometry. Surface Photoabsorption and Brewster Angle Reflectometry. Reflectance-Difference (Anisotropy) Spectroscopy. Ellipsometry.Interferometry and Photography: Interferometry. Photography, Imaging, and Microscopy. Elastic Scattering and Diffraction from Particles and Nonplanar Surfaces (Scatterometry): Detection of Particles. Diffraction from Surface Features. Speckle Photography and Interferometry. Raman Scattering: Kinematics and Dynamics of Spontaneous Raman Scattering. Instrumentation. Thermometry and Density Measurements in Gases. Real-Time Raman Probing of Solids and Surfaces. Pyrometry: Theoretical and Experimental Considerations. Single-Wavelength Pyrometry. Dual-Wavelength Pyrometry. Pyrometric Interferometry. Thermal Radiation during Pulsed-Laser Deposition. Photoluminescence: Experimental Considerations. Probing Defects and Damage. Thermometry. Spectroscopies Employing Laser Heating: Laser-Induced Thermal Desorption. Thermal Wave Optical Spectroscopies. Nonlinear Optical Diagnostics: Coherent Anti stokes Raman Scattering. Surface Second-Harmonic Generation. Third-Harmonic Generation in Gases. Optical Electron/Ion Probes: Photoionization. Photoemission. Optogalvanic Spectroscopy. Optical Thermometry: The Need for Thermometry in Thin Film Processing. Nonoptical Probes of Temperature. The Physical Basis of Optical Thermometry. Comparison of Optical Thermometry Probes. Appendix: Representative Citations in Real-Time Optical Thermometry in Thin Film Processing. Reviews of Optical Thermometry. Citations for Optical Thermometry in Gases. Citations for Optical Thermometry of Wafers. Data Analysis and Process Control: Data Acquisition and Analysis. Process Modeling. Process Control. References. Subject Index.