Vertical FET Bottom Junction Epitaxy

The patent applies preliminary action by forming sacrificial layers and spacers before the actual doping process. The sacrificial layers are deposited and patterned first, followed by spacer formation, which defines the precise locations where dopants will later be introduced. This preparatory structure ensures accurate dopant placement without requiring complex real-time control during doping.

The patent uses sacrificial layers and spacers as intermediary structures to achieve precise dopant placement. These intermediary elements serve as templates that guide dopant introduction, allowing indirect control over dopant positions. The spacers act as mediators that define the exact regions where dopants should be placed, improving precision without direct manipulation during doping.

The patent applies local quality by creating distinct regions with different properties through the spacer structure. The spacers define specific local zones along the fin where dopants are introduced, ensuring uniform dopant distribution in each localized region. This local control mechanism ensures consistent junction characteristics along the entire fin length, as each segment receives precisely controlled dopant amounts.

The patent segments the doping process into discrete regions defined by the spacer structures. Instead of uniform doping across the entire fin, the process is divided into separate segments corresponding to different spacer locations. This segmentation allows independent control of dopant placement in each region, ensuring uniformity across the whole structure while maintaining efficient processing.