Inline Detection of DRAM Container Etch Slant using Secondary Electron Detector on CD-SEM

This paper presents a new inline detection metric for DRAM container slanting caused by changes in plasma ion trajectory during the oxide dry etch process. The new method using secondary electron detection provides a practical alternative to backscatter electron detection or destructive techniques traditionally used for high-aspect-ratio profile characterization. The effectiveness of the metric is validated through TEM measurements and it trends with dry etch chamber RF hours. In addition, we demonstrate a clear relationship between the inline metric and yield performance, enabling earlier detection of chamber drift and improved process control.