3D NAND Interconnect Structure for Reliable Chip-to-Chip Coupling

The patent transitions from planar interconnect structures to three-dimensional coupling portions that extend vertically through multiple layers. The coupling portions penetrate through the source line layer and extend into the memory pillar region, establishing electrical connections in the vertical dimension rather than relying solely on planar connections. This dimensional transition enables reliable electrical connectivity while accommodating the three-dimensional memory architecture.

The coupling portions are nested within the three-dimensional memory structure, with conductive regions embedded within insulating layers and memory pillars. The interconnect structure is nested within the memory cell array, with coupling portions positioned within trenches that are filled with conductive material. This nesting approach allows multiple functional elements to be integrated within the vertical space of the three-dimensional structure while maintaining electrical connectivity.

The patent merges the interconnect structure with the memory cell array structure by integrating coupling portions that simultaneously serve as interconnect elements and structural components of the memory pillars. The source line layer is merged with the coupling portion structure, where the same conductive regions serve dual functions as both interconnect pathways and structural supports for the memory cells. This merging reduces the number of separate components and simplifies the overall device architecture.

The coupling portions serve multiple functions: they act as vertical interconnects for electrical signaling, provide structural support for the memory pillars, and establish electrical connections between different chip layers. The source line layer serves both as a bit line interconnect and as a structural element that defines the memory cell regions. This multi-functionality reduces the number of dedicated components needed, thereby reducing device complexity.