Abstract
Secondary electrons potential contrast (SEPC) by scanning electron microscopy has emerged as a powerful tool for two-dimensional quantitative dopant imaging. The main component of the SEPC signal arises from the difference in the built-in potential between differently doped regions; which is very high in wide-band-gap semiconductors and particularly intense in SiC. This paper, after discussing the physical principles leading to the dopant contrast and the proper experimental setup, investigates the impact of relevant factors such as experimental conditions, surface effects, and sample preparation on image quality. The quantitative capabilities of this technique are demonstrated by the analysis of different test structures and prototypes of power devices such as MOSFET and JFET. The application to completely process devices demonstrates that SEPC represents an unequalled characterization technique, which provides accurate imaging and dopant profiling capabilities for silicon carbide devices.
