Non-volatile Memory Array Area Reduction via Segmented Active Regions

The patent segments the bit cell structure by assigning different active region pairs to adjacent bit cells sharing a bit line. Specifically, first bit cells share a first pair of active regions while second bit cells share a second pair of active regions, allowing spatial separation of write operations without physical isolation structures. This segmentation enables reliable writing to selected bit cells while preventing unintended writes to adjacent cells, resolving the contradiction between writing reliability and area efficiency.

The patent extracts and eliminates the need for isolation elements (such as deep trenches or thick dielectric layers) by implementing a layout architecture where adjacent bit cells naturally isolate write operations through their distinct active region assignments. By taking out these complex isolation structures and replacing them with a simplified active region pairing scheme, the invention reduces device complexity and manufacturing cost while maintaining writing reliability through the segmented active region architecture.

The patent applies local quality by assigning different active region configurations to different groups of bit cells. Specifically, first bit cells are configured with a first pair of active regions while second bit cells use a second pair of active regions, creating localized structural differences that prevent writing errors. This local differentiation allows continuous parallel extension of active regions for area efficiency while ensuring writing accuracy through group-specific active region assignments that isolate write operations to intended bit cells only.