Word Line Driver Homogeneity for 3D Memory Area Efficiency

The patent applies homogeneity by using transistors of the same conductivity type (either all N-type or all P-type) throughout the word line driver circuit. This eliminates the need for separate N-well and P-well regions, allowing uniform transistor design and placement. The uniformity simplifies the layout process, reduces the overall circuit area, and significantly decreases metal routing complexity since no special well-region constraints need to be accommodated.

The patent changes the fundamental parameter of transistor conductivity type selection from a mixed approach (N-type and P-type) to a uniform approach (single type). This parameter change enables more efficient area utilization and simplifies the interconnection design, as uniform transistors can be densely packed without worrying about well-isolation requirements, directly addressing both layout area efficiency and routing complexity.

The patent segments the word line driver circuit into modular units with uniform transistor structures. This segmentation allows the peripheral circuits to be efficiently placed under memory arrays in 3D configurations, as each module has standardized dimensions and connection requirements. The uniform transistor design within each segment simplifies the overall routing planning, reducing decoder routing complexity even in dense 3D layouts.

By using homogeneous transistor structures throughout the peripheral circuits placed under memory arrays, the patent creates uniform building blocks that can be systematically arranged in 3D space. This homogeneity reduces the routing complexity associated with decoder connections, as identical transistor types require identical well regions and connection patterns, making the overall routing design more predictable and manageable.