Currently, wafers are loaded on a passive wafer stage. This process induces residual stresses due to non-reproducible friction forces between the wafer and the wafer table. The residual stresses can cause overlay errors between different patterning steps which are one of the primary challenges in the semiconductor industry. A new actuated wafer table is designed which counteract the static deformations in the wafer by actuating the wafer table conformal to the wafer. This method could reduce the residual stresses in the wafers by neutral plane matching between the wafer and wafer table. This research creates a systematic approach to design a segmentation pattern for the actuators on the wafer table to control as many wafer shapes as possible. This approach is used to investigate various segmentation patterns for the actuated wafer table.
Systematic Approach for Designing a Segmentation Pattern for an Piezo Actuated Wafer Table
Vorwerk, S. G. M. (Author). 23 Feb 2022
Student thesis: Master