Determination of pore-size distributions in low-k dielectric films by transmission electron microscopy

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 low-angle ion milling. Knowledge of TEM sample thickness allows quantification of pore density distributions. TEM sample thickness and quantitative image analysis methods are discussed.