Wooptix advances wafer metrology
Wooptix highlights full-wafer shape measurement as a tool for improving bonding control in HBM stacks and backside power delivery.
Wooptix is highlighting wavefront phase imaging (WFPI) as a metrology approach for improving process control in advanced semiconductor packaging, where wafer distortion can affect bonding alignment, manufacturing yield and downstream processing.
In a technical article by Miguel Jimenez-Gomis, senior application engineer at Wooptix, the company explains how full-field wafer-shape measurements can help identify complex deformations arising during direct wafer-to-wafer bonding.
These distortions are increasingly important as manufacturers develop high-bandwidth memory (HBM) stacks and backside power delivery networks with tighter alignment tolerances.
Conventional metrology methods can struggle to provide rapid, full-wafer measurements at the pace required for high-volume manufacturing.
WFPI captures wafer shape across the entire surface and can identify higher-order deformation patterns that simple bow measurements may not reveal.
According to Wooptix, the resulting data can be used to model in-plane stresses associated with bonding and support feed-forward process control.
Manufacturers could use these measurements to refine bonding parameters and reduce the risk of downstream issues in chemical-mechanical planarisation (CMP), lithography and subsequent stacking processes.
The company also highlights WFPI’s ability to measure patterned wafers and emerging substrates such as glass, where some conventional interferometry techniques face limitations.
As advanced packaging architectures push towards finer pitches, more complex stacking and increasingly demanding overlay requirements, full-wafer shape metrology could provide additional insight into process-induced deformation.
Wooptix positions WFPI as a potential tool for developing predictive models and improving control of wafer bonding processes.
