Sub micron defect detection by SEMSpec- an E-beam wafer inspection system

摘要

Traditionally, automated optical inspection techniques have been sufficient to find defects on wafers. However, defects smaller than 0.25μ simply cannot be resolved by light optics due to optical limitation. KLA-Tencor SEMSpec is an advanced scanning electron-beam wafer inspection system that can detect defects down to 0.1μ. The electron beam is scanned over the specimen surface, causing secondary electrons to be emitted from the surface where the beam impinges. These emitted secondary electrons are detected and the resulting image is formed so that conventional image processing techniques can also be applied. In the inspection sequence, fundamental parameters such as pixel size, defect detection sensitivity threshold, signal averaging, and cluster distance can be adjusted. The system description, system operation, and system performance are described in this paper.