Development of Atomic Scale Tomography for Quantification of Radiation Induced Defects in Microelectronic Devices

Dimensional and compositional metrology of small-scale microelectronics, less than 22 nm, is becoming increasingly difficult as the architecture of these devices is becoming more complex. Key metrological measurements of Fin devices require 3-D metrology at less than 0.5 nm spatial resolution as well as single atom characterization to identify device composition and chemical distributions. This is especially true when analyzing the effect of radiation hardening on microelectronic reliability. None of the current techniques for microelectronic metrology, such as atom probe tomography (APT) and scanning transmission electronic microscopy (STEM), can achieve all the required metrics with the necessary sensitivity and atomic scale resolution. In this project, STEM and APT will be combined in an Atomic Scale Tomography (AST) tool to leverage the spatial resolution of electron microscopy and single atom chemical sensitivity of atom probe tomography for 3D analysis of FinFET transistors and gate stacks. The proposed system will contain a TEM tomography sample holder that is capable of layer by layer ion evaporation for time of flight analysis. AST will allow for STEM imaging before and after evaporation, as well as collection of electron diffraction patterns and other analytical techniques. By combining TEM imaging and diffraction, users can compare compositional results from APT with structural data from STEM layer by layer to place single atoms onto a 3-D real space specimen representation with Angstrom level spatial resolution.