X-ray structure characterization of barriers for Cu metallization

The possibilities and limitations of X-ray scattering techniques are discus sed for the structure analysis of Ta-N barriers for Cu metallization. Diffr action measurements under grazing incident angle enable to analyze the phas e composition and to determine structural parameters of 10 nm Ta-N films on to (100)-silicon wafers. Depending on the nitrogen flow nanocrystalline bcc Ta(N), fcc TaN, and amorphous Ta(N) phases were observed in the sputtered films. X-ray specular reflectivity measurements were explored to estimate f ilm thickness and roughness as a function of preparation in a good agreemen t with transmission electron microscopy investigations. (C) 2000 Elsevier S cience Ltd. All rights reserved.