Electron Holography as Characterization Tool for 2-D Analysis of p-n Junctions

Abstract

We review formation of an electron hologram in TEM for analysis of p-n junctions in semiconductor devices. It is shown on the basis of comparison of results of electron holography and SIMS that the method can provide quantitative information directly, i.e. without consideration of "dead layers" in both bulk Si and SOI structures. Unique information provided by electron holography addresses a wide range of problems concerned with understanding dopant diffusion, process integration and physical failure analysis. In particular, it is proved that laser anneal does not cause lateral dopant diffusion of As to resolution of the method and demonstrated that junction overlap can be achieved with "laser-only" integration scheme We show how position of p-n junctions prior to annealing can be deduced from holography analysis to help tune process integration. Examples concerning physical failure analysis cover blocked implants, effect of STI proximity on dopant depletion.