BCAT Word Line Trench Formation via Sacrificial Layer Segmentation

The patent divides the word line formation process into multiple discrete steps using different sacrificial layers (first, second, and third sacrificial layers) with distinct materials and removal sequences. This segmentation allows precise control over the trench formation process, enabling reliable electrical connections even in highly integrated devices with reduced area.

The patent employs preliminary actions by forming multiple sacrificial layers before the actual word line trench formation. These sacrificial layers are sequentially removed to create the trench structure, ensuring that the trench is formed with precise dimensions and proper isolation from surrounding structures, thereby maintaining electrical reliability in compact designs.

The patent uses sacrificial layers as intermediary materials that facilitate the formation of the word line trench. These intermediaries are temporarily introduced, precisely patterned, and then selectively removed to create the desired trench structure. This approach achieves high manufacturing precision while managing complexity through the systematic use of removable intermediary structures.

The patent employs multiple sacrificial layers that are sequentially removed after serving their patterning function. Each sacrificial layer is discarded after enabling the formation of the next structural element, allowing complex precise patterning to be achieved through a series of simpler, manageable steps rather than a single complex process.