COPPER DECORATION FOLLOWED BY TEM OBSERVATION DEFECTS IN THE BURIED OXIDES OF SOI SUBSTRATES

Copper decoration followed by transmission electron microscopy (TEM) o bservation is proposed for identifying defects in the buried oxides of silicon-on-insulator (SOI) substrates. This method comprises Si surfa ce layer etching (i.e., exposure of the buried-oxide surface), oxide-d efect location detection with copper decoration, and sample thinning f or TEM observation and analysis. The advantage of copper decoration is that the electronic current needed for defect detection is very small , so the influence of the electronic current on the original oxide-def ect structure can be minimized. Defects observed are categorized into four groups from the viewpoint of size and shape.