Semiconductor Cell Contact Plug Formation via Sacrificial Layer Expansion

The patent applies preliminary action by forming extension portions from sacrificial layers before forming the cell contact hole. These extension portions protrude into the cell contact hole and serve as pre-positioned structures that prevent residual dielectric liners from remaining between the cell contact plug and gate electrodes, thereby eliminating punch-through failures before they can occur during subsequent processing steps.

The extension portions formed from sacrificial layers act as intermediary structures during the cell contact hole formation process. These intermediaries fill the space between the gate electrodes and the cell contact plug, ensuring complete removal of residual oxide layers and dielectric liners, and then are replaced by the gate electrodes themselves, thus mediating the interface between the cell contact plug and gate electrodes without leaving harmful residues.

The patent performs preliminary patterning to form extension portions from sacrificial layers that protrude into the cell contact hole region before the actual cell contact hole etching. This preliminary structuring ensures precise definition of the cell contact plug formation area, as the extension portions serve as etch stop layers and position references, thereby improving manufacturing precision without requiring additional post-etch correction steps.

The patterning process is segmented into multiple stages: first forming extension portions from sacrificial layers, then forming the cell contact hole through the extension portions, and finally replacing the extension portions with gate electrodes. This segmentation allows each step to be optimized independently, with the extension portions providing precise spatial control for the cell contact hole formation, thereby improving overall manufacturing precision.

The extension portions formed from sacrificial layers serve as intermediary protective structures during the cell contact hole etching process. These extension portions are positioned at the interface between the cell contact hole and the channel structure, acting as barriers that prevent etching materials like fluorine from penetrating into the channel structure, thereby protecting the electrical performance while still allowing the cell contact hole to be formed.

The patent applies preliminary anti-action by forming extension portions from sacrificial layers before the etching process. These extension portions are specifically designed to counteract the harmful effect of etching material penetration by providing a physical barrier and etch stop layer that prevents fluorine and other etching materials from reaching and degrading the channel structure, thus preemptively neutralizing the harmful effect.