Site-Specific 2D carrier profiling in Si devices by Scanning Spreading Resistance Microscopy (SSRM)

As semiconductor devices are scaling down, understanding the two-dimensional carrier profile is vital to improving the overall performance of various silicon devices, and crucial when conducting failure analysis. In this paper, we demonstrated several site-specific 2D carrier profiles, for both n-MOS and p-MOS in static random access memory(SRAM) devices using scanning spreading resistance microscopy (SSRM). For the purpose of observing the site-specific characteristics of SRAM devices, we used focus ion beam(FIB) in our sample preparation. To further improve the positioning accuracy to within a dozen nanometers, the full FIB pick up method was also adopted. This particular approach allowed us to better conduct site-specific observations.