Imec and PVA Tepla claim a breakthrough in the detection of through-silicon via (TSV) voids in 3D stacked IC technology.
They used GHz scanning acoustic microscopy (SAM) technology to detect TSV voids at wafer-level after TSV Copper plating.
This addresses the challnege of handling temporary wafer (de)bonding and thin wafer for 3D stacked IC technology.
The development of interface particles and voids during the temporary bonding process has a detrimental impact on the subsequent wafer thinning process steps, affecting the wafer thinning performance as well as long-term tool stability and performance.
Scanning Acoustic Microscopy PVA Tepla and Imec have developed an automated foup-to-foup, wafer-level process based on 200MHz Scanning Acoustic Microscopy (SAM) using Tepla’s AutoWafer 300 tool.
After demonstrating non-destructive detection of interface particles and voids, imec used PVA Tepla’s high-resolution capability GHz frequency SAM tool to successfully detect voids in TSVs of 5µm diameter and 50µm depth, immediately after plating.
The intention now is to refine the process and implement GHz SAM capability to increase the spatial detection resolution.
Imec and PVA Tepla will also investigate bump connection quality.
