Thomas Schmidt

Thomas Schmidt is Product Manager in the Bonder Division of SUSS MicroTec in Sternenfels. After his graduation in Microsystems Technology at the University of applied sciences in Kaiserslautern he has held various positions in MEMS/semiconductor processing and has also lectured on advanced lithography as well as on MEMS and advanced CMOS fabrication.

Since December 2017 Thomas Schmidt is a member of the Bonder Division of SUSS MicroTec product line “Permanent Wafer Bonding“) with a strong focus on automated cluster platforms for MEMS/packaging applications and hybrid bonding for advanced packaging.

3DIC W2W and D2W Hybrid Bonding

Replacing traditional solder based micro-bump interconnects with Hybrid Bonding process flows is still considered a game changer for 3D integration. This interconnect method offers a unique solution for contact pitch scaling and therefore is in the spotlight of R&D roadmaps at all major research institutions, IDMs and foundries as well as the equipment and materials industry. In order to ensure optimum overlay results to allow for small interconnect pitches, the best possible alignment accuracy and repeatability needs to be consistently maintained during the joining process. Depending on the specific application there are different processing schemes for Hybrid Bonding which co-exist. These include wafer to wafer (W2W), collective die to wafer (CoD2W) as well as sequential die to wafer (D2W) approaches which all need to be carried out at cleanliness levels that are comparable to front-end-of-line (FEOL) requirements. Each of these process flows comes with specific challenges which need to be addressed from an equipment as well as a process perspective. SUSS MicroTec leverages its leading position in wet processing and precision alignment for wafer level processes and has partnered with SET (Smart Equipment Technology), who is one of the technology leading flip-chip bonder manufacturers. SUSS MicroTec looks back at many years of hybrid bonding co-optimization activities with the research partner imec for collective D2W, while SET has worked for many years with CEA Leti on sequential D2W. Our solutions are optimized based on the learnings from these activities. In order to ensure optimum yield it is essential to monitor the overlay results with no blind spots across the wafer. Therefore a high throughput metrology system has been developed at SUSS MicroTec, which can be used for in-line inspection to trigger control loops and to record quality data for all dies on the wafer. Stand-alone metrology solutions with multiple overlay verification modules allow customers to scale their measurement capabilities according to their manufacturing needs. Specific state-of-the art alignment and overlay results for both, integrated W2W and D2W Hybrid Bonding schemes will be reviewed.