High Resolution X-ray Scattering Methods For ULSI Materials Characterization

摘要

X-ray analytical methods with high angular resolution are becoming increasingly important for the characterization of materials used in ULSI fabrication. Vendors now market state-of-the-art X-ray tools for the routine analysis of parameters such as layer thickness, chemical composition, strain relaxation, and interfacial roughness. The recent integration of X-ray diffraction and reflectivity systems into fab-compatible process metrology tools suggests that the importance of these techniques will only increase with time. Here we discuss some basic principles of high resolution X-ray methods (notably double- and triple-axis X-ray diffractometry and high resolution X-ray reflectometry) and will describe the capabilities and limitations of these tools for ULSI materials. Reference will be made to "real-life" problems involving bulk and thin-film structures (ranging from amorphous dielectrics and polycrystalline metals to highly perfect epitaxial single crystal materials) to show both the utility and the shortcomings of high resolution X-ray methods.