Development of a secondary-electron detection system for high-speed high-sensitivity inspection SEM imaging

Electron optics and secondary-electron (SE) detection systems that increase the speed and sensitivity of SEM imaging systems used for inspecting semic onductor devices have been developed. Direct and indirect SE detection syst ems optimized for retarding electron optics were investigated. In indirect detection, SEs are deflected to a converter electrode, and a detector colle cts the SEs generated from the electrode. Simulation of the SE trajectories showed that indirect systems are capable of stable high-efficiency SE coll ection at various retarding voltages, V-r. Indirect systems were developed and found that various V-r can be applied to a sample to achieve stable SE collection efficiency.