24 May 2004 Segmented alignment mark optimization and signal strength enhancement for deep trench process
Author Affiliations +
Abstract
This study characterizes the process influence on the alignment signal of deep trench (DT) process, and correlates product overlay with alignment results based on volume production data. The affecting processes include various steps of polysilicon thickness, nitride and oxide films, recess etch depth control, and resist thickness impact. Correlation also proves that the alignment signal plays an important role at the resulted long-term overlay stability. In order to improve the signal strength, further study focuses on the alignment optimization through mark design for deep trench process. The alignment marks evaluated include Scribe-lane Primary Marks (SPM) with difference process segmentations, short SPM marks and Versatile SPM marks. A good correlation is established between varying trench width or line width of mark segmentation and alignment signal strength. Comparison is also done for the signal strength between SPM mark and SSPM marks, between standard SPM mark and pure higher order marks.
© (2004) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Yuanting Cui, Frank Goodwin, Richard van Haren, "Segmented alignment mark optimization and signal strength enhancement for deep trench process", Proc. SPIE 5375, Metrology, Inspection, and Process Control for Microlithography XVIII, (24 May 2004); doi: 10.1117/12.532896; https://doi.org/10.1117/12.532896
PROCEEDINGS
13 PAGES


SHARE
Back to Top