Determination of Pore-Size Distributions in Low-k Dielectric Films by Transmission Electron Microscopy

Abstract

This paper discusses methods of characterizing pore size distributions in low dielectric constant (low-k) films by transmission electron microscopy (TEM), comparing both conventional TEM and high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM). Methods of sample preparation were tailored to protect pore structure during cross-sectional thinning allowing techniques similar to conventional mechanical polishing and lowangle ion milling. Knowledge of TEM sample thickness allows quantification of pore density distributions. TEM sample thickness and quantitative image analysis methods are discussed.