Inline SEM imaging of buried defects using novel electron detection system: DI: Defect inspection and reduction

As the semiconductor industry moves to sub 1× nm nodes, with complex 3D structures, high aspect ratio (HAR) features and multiple patterning steps, the ability to detect and characterize defects is becoming increasingly difficult. Defects, located at the bottom of HAR structures or buried in the previous layers, are making the devices vulnerable to failure. It is critical to characterize these defects to understand the failure mechanism, to qualify a new process and for accurate yield prediction. For failure analysis, the defect locations on the wafer are marked and sent for Transmission Electron Microscopy (TEM) imaging, leading to high cycle times, with limitation on number of locations on the wafer. In this paper, we present results from novel backscattered electron (BSE) detection, where inline Scanning Electron Microscopy (SEM) images can provide vital information regarding the failure mechanism in much shorter cycle times, with no limitations on number of locations.