Quantitative nanoscale metrology study of Cu/SiO2 interconnect technology using transmission x-ray microscopy

Abstract

This letter describes quantitative nondestructive measurements of multilayer submicron Cu/SiO2 interconnect structures such as Cu lines, vias, and W lines with lateral dimensions down to 300 nm and electromigration defect structures using scanning transmission x-ray microscopy employing a 0.2 μm x-ray beam. Typical measurement accuracies are ⩽60 nm for widths and lengths and ⩽10% in height. The high-resolution and nondestructive nature of this technique provide a very powerful probe of physical properties of nanoscale and submicron materials and structures.

Electromigration of Cu/low dielectric constant interconnects

“…Void growth and extrusion of the tested lines were also examined by FIB and SEM on cross-sections prepared by FIB. Other investigators have used transmission X-ray microscopy [40,41] or high-voltage (120 keV) SEM [42] to observe void size and growth. Rutherford back scattering (RBS) analysis was used to determine the composition of the CoWP metal layer.…”

Quantitative metrology study of Cu/SiO2 interconnect structures using fluorescence x-ray microscopy

“…A significant advantage of using fluorescence microscopy is that, e.g., compared to transmission microscopy, 10 SXFM measurements have a very low background level, thus much higher signal-noise ratio and better detectability of small quantities. The height of the lines can be obtained directly from the intensity of the fluorescence signals.…”

The Scanning Confocal Electron Microscope: A New Tool for Defect Studies in Semiconductor Devices

“…Microscope (STXM) [2] or involves the careful preparation of thin cross-section slices for study Metrological studies of sub-micron, sub-surface using the Transmission Electron Microscope features of thick optically dense materials at high (TEM or STEM) [3]. In case of defects, resolution have always been a difficult and/or time deprocessing procedures relaying on chemical consuming task in materials research.…”