Microstructure isolation testing using a scanning electron microscope

Abstract
A new form of testing is described that is suitable for verifying isolation in many forms of microstructures. Excess charge is deposited on the microstructures by a scanning electron microscope (SEM) beam. On elements of the microstructures that are isolated, this excess charge induces a voltage contrast that is detected at the same time by the same beam. Isolation to approximately 2×1011 Ω can be verified. The method is simple and fast, requiring only a standard SEM and simple test structures.