High Resolution X-ray Scattering Methods For ULSI Materials Characterization

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 short...