There are some advantages to performing physical failure analysis from the backside as opposed to normal frontside analysis. However, there are challenges to be overcome with regard to sample preparation and scanning electron microscopy. Thus, we introduce this unusual technique to overcome the barrier of difficulty. This technique can eventually lead to the development of a versatile methodology that can be used in actual applications for failure analysis.

The Voltage Contrast (VC) [1-3] and Dopant Contrast [4-7] in Scanning Electron Microscopy (SEM) [8] have been widely used in the Silicon (Si) semiconductor manufacturing field to localize the failure site from plane-view and inspect the doping profile along cross-section with spatial resolution in the nanometer (nm) range. In this article, we demonstrate how the surface effect, such as topography or material variation, impacts the conventional prediction for the voltage and dopant contrast in the SEM images. The mechanisms and applications for the SRAM and real products are described.