Self-Aligned FinFET and Deep Trench Capacitor Integration in SOI

The patent applies preliminary action by forming a self-aligned structure before final patterning. The deep trench capacitor and FinFET are formed with pre-established alignment relationships, where the capacitor trench is defined relative to the fin structure before subsequent processing steps. This preliminary self-aligned formation prevents misalignment-induced shorting and reduces strap resistance by optimizing the connection geometry between capacitor and fin.

The patent introduces an intermediary material layer (such as a dielectric or conductive bridge) between the deep trench capacitor and the FinFET structure. This intermediary element serves as a controlled connection pathway that reduces strap resistance while preventing direct shorting between adjacent structures. The intermediary layer is specifically designed to provide optimal electrical connection while maintaining structural isolation where needed.

The patent merges the formation processes of deep trench capacitors and FinFET structures into a unified self-aligned fabrication sequence. By combining these two complex structures into a single integrated formation process, the patent reduces the number of separate lithography and etching steps required, thereby simplifying integration while maintaining the performance benefits of three-dimensional FinFET geometry.

The patent creates a universal self-aligned fabrication approach that can be applied to various device configurations and capacitor types within the SOI platform. The methodology provides a multi-functional solution that works for different fin geometries, capacitor arrangements, and device densities, thereby reducing integration complexity across diverse circuit designs while preserving FinFET scalability.