In this paper we will show the improvement in imaging OVL measurement accuracy using wave tuning (WT) capability combined with advanced algorithms to address 3D NAND process challenges. In addition to new OVL target designs that take advantage of WT capability, we also demonstrate improvement in OVL model residuals through optimization of measurement bandwidth, focus position and number of grab frames. Improvements in precision and tool-to-tool matching are also realized through both optimization of the region of interest (ROI) and splitting measurement areas using a dual-recipe technique. |
ACCESS THE FULL ARTICLE
No SPIE Account? Create one
CITATIONS
Cited by 1 scholarly publication.
Overlay metrology
Semiconducting wafers
3D acquisition
3D image processing
Imaging metrology
Scanning electron microscopy
Optimization (mathematics)