Introduction Failure analysis is a vital process in the development of a new product and/or improvement of existing products in the semiconductor industry. Successful failure analysis can identify the root cause of a failed device and guide through corrective actions. Semiconductor failure analysis often involves a number of different techniques, such as curve tracing, scanning electron microscopy, transmission electron microscopy, microthermography, focused ion beam analysis, etc. As a relatively new tool, atomic force microscopy (AFM) based techniques, such as scanning capacitance microscopy, conductive AFM, and scanning spreading resistance microscopy, have been applied to analysis of various failed devices [1]. In this article, the recently developed scanning microwave microscopy (SMM) [2-5] is demonstrated, for the fi rst time, its capability of doing semiconductor failure analysis.