A 331-Beam Scanning Electron Microscope

The continuous shrink of semiconductor patterns imposes many challenges on the fabrication of semiconductor devices, not only on the patterning process itself, but also on the inspection of these patterns. The required resolution is becoming increasingly difficult to achieve with current optical inspection techniques. Inspection technologies based on scanning electron microscopy (SEM) can resolve the relevant patterns and defects but have not been able to achieve the throughput requirements for screening large areas yet. This article reports on a 331-beam SEM that increases the throughput of existing multi-beam technology by another factor of more than three.