X-Ray Metrology in Semiconductor Manufacturing

The scales involved in modern semiconductor manufacturing and microelectronics continue to plunge downward. Effective and accurate characterization of materials with thicknesses below a few nanometers can be achieved using x-rays. While many books are available on the theory behind x-ray metrology (XRM), X-Ray Metrology in Semiconductor Manufacturing is the first book to focus on the practical aspects of the technology and its application in device fabrication and solving new materials problems.

Following a general overview of the field, the first section of the book is organized by application and outlines the techniques that are best suited to each. The next section delves into the techniques and theory behind the applications, such as specular x-ray reflectivity, diffraction imaging, and defect mapping. Finally, the third section provides technological details of each technique, answering questions commonly encountered in practice. The authors supply real examples from the semiconductor and magnetic recording industries as well as more than 150 clearly drawn figures to illustrate the discussion. They also summarize the principles and key information about each method with inset boxes found throughout the text.

Written by world leaders in the field, X-Ray Metrology in Semiconductor Manufacturing provides real solutions with a focus on accuracy, repeatability, and throughput.

Inhalt

THE APPLICATIONS

Introduction
Scope of X-Ray Metrology (XRM)
Specular X-Ray Reflectivity (XRR)
Diffuse Scatter
X-Ray Diffraction
High-Resolution X-Ray Diffraction
Diffraction Imaging and Defect Mapping
X-Ray Fluorescence
Summary
Thickness Metrology
Introduction
Dielectrics and Metals
Multiple Layers
Epitaxial Layers
Summary
Composition and Phase Metrology
Introduction
Amorphous Films
Polycrystalline Films
Wafers and Epitaxial Films
Summary
References
Strain and Stress Metrology
Introduction
Strain and Stress in Polycrystalline Layers
Relaxation of Epitaxial Layers
Thin Strained Silicon Layers
Whole Wafer Defect Metrology
Summary
References
Mosaic Metrology
Grain Size Measurement
Mosaic Structure in Substrate Wafers
Mosaic Structure in Epilayers
Summary
References
Interface Roughness Metrology
Interface Width and Roughness
Distinction of Roughness and Grading
Roughness Determination in Semiconductors
Roughness Determination in Metallic Films
Roughness Determination in Dielectrics
Summary
References
Porosity Metrology
Determination of Porosity
Determination of Pore Size and Distribution
Pores in Single Crystals
Summary
References

THE SCIENCE

Specular X-Ray Reflectivity
Principles
Specular Reflectivity from a Single Ideal Interface
Specular Reflectivity from a Single Graded or Rough Interface
Specular Reflectivity from a Single Thin Film on a Substrate
Specular Reflectivity from Multiple Layers on a Substrate
Summary
References
X-Ray Diffuse Scattering
Origin of Diffuse Scatter from Surfaces and Interfaces
The Born Approximation
The Distorted-Wave Born Approximation
Effect of Interface Parameters on Diffuse Scatter
Multiple-Layer Structures
Diffuse Scatter Represented in Reciprocal Space
Summary
References
Theory of XRD on Polycrystals
Introduction
Kinematical Theory of X-Ray Diffraction
Determination of Strain
Determination of Grain Size
Texture
Reciprocal Space Geometry
Summary
References
High-Resolution XRD on Single Crystals
Introduction
Dynamical Theory of X-Ray Diffraction
The Determination of Epilayer Parameters
High-Resolution Diffraction in Real and Reciprocal Space
Summary
References
Diffraction Imaging and Defect Mapping
Introduction
Contrast in X-Ray Diffraction Imaging (XRDI)
Spatial Resolution in XRDI
X-Ray Defect Imaging Methods
Example Applications
Summary
References

THE TECHNOLOGY

Modeling and Analysis
What Has Been Measured?
Direct Methods
Data-Fitting Methods
The Differential Evolution Method
Requirements for Automated Analysis
Summary
References
Instrumentation
Introduction
X-Ray Sources
X-Ray Optics
Mechanical Technology
Detectors
Practical Realizations
Summary
References
Accuracy and Precision of X-Ray Metrology
Introduction
Design of X-Ray Metrology
Repeatability and Reproducibility
Accuracy and Trueness
Repeatability and Throughput
Absolute Tool Matching
Specimen-Induced Limitations
Summary
References
INDEX