3D AND Flash Memory Pillar Fabrication via Sacrificial Layer Replacement

The patent transitions from planar 2D flash memory structures to a three-dimensional architecture by stacking multiple insulating layers and sacrificial layers vertically to form pillar structures. This vertical stacking approach increases integration density by utilizing the third dimension (height) rather than only expanding in the planar area, thereby improving productivity through higher integration levels while managing structural complexity through systematic layer formation.

The memory structure is segmented into multiple functional layers including first insulating layers, sacrificial layers, channel layers, and conductor layers that are alternately stacked. Each layer serves a specific function and can be independently formed and controlled. This segmentation allows for modular manufacturing processes where each layer can be optimized separately, improving overall integration while maintaining manageable complexity through standardized layer formation techniques.

Sacrificial layers are formed in advance between the insulating layers before the final memory structure is completed. These preliminary sacrificial structures serve as templates that guide the subsequent formation of channel layers and conductor layers. By performing this preliminary action, the patent simplifies later manufacturing steps and improves process yield, as the sacrificial layers provide precise spatial guidance for subsequent material deposition and patterning operations.

The sacrificial layers act as intermediary elements during the manufacturing process. They are temporarily introduced to define the spatial arrangement of pillar structures, then removed and replaced with conductor layers in a controlled replacement process. This intermediary approach simplifies the overall manufacturing by providing a temporary but precise template that ensures high integration levels while maintaining process yield through standardized formation and replacement procedures.

The patent implements local quality by providing independent conductor layers for each pillar structure, allowing selective activation of specific memory cells. Each pillar structure with its associated conductor layers can be independently controlled, enabling arbitrary memory cell selection. This local differentiation in conductor layer configuration allows high operation speed through selective cell access while managing complexity through a systematic pattern that repeats across the memory array.

The memory structure utilizes three-dimensional stacking with pillar structures extending vertically through multiple insulating layers. Independent conductor layers are positioned at different heights and locations within this 3D structure, enabling selective access to specific memory cells by activating particular conductor layers. This dimensional approach allows arbitrary cell selection for high operation speed while managing complexity through a regular repeating pattern of pillars and conductors in three-dimensional space.