GAA and FinFET Co-Fabrication Using a Shared Layer Stack

The patent combines the fabrication processes for GAA transistors and FinFETs into a single unified process. By forming a common substrate with alternating semiconductor and sacrificial layers, both device types can be manufactured simultaneously in different regions of the same substrate, eliminating the need for separate epitaxial layer formations and reducing overall manufacturing complexity and cost.

The substrate structure is designed to serve multiple functions: it can form both GAA transistors in first regions and FinFETs in second regions using the same initial epitaxial layers. The alternating semiconductor and sacrificial layer configuration allows the same substrate to be processed differently in different regions to produce two distinct device types, achieving multi-functionality from a single fabrication approach.

The patent applies local quality by allowing different processing steps to be applied to different regions of the same substrate. While the initial epitaxial layer formation is uniform across the substrate, subsequent processing can be selectively applied to first regions (for GAA transistors) and second regions (for FinFETs), enabling each device type to receive optimized local treatment while sharing the common substrate foundation.

The substrate is segmented into different functional regions: first regions for GAA transistor fabrication and second regions for FinFET fabrication. This segmentation allows the same initial structure to be divided into zones that receive different subsequent processing, enabling both device types to achieve their specific performance requirements through region-specific optimization while maintaining a unified starting point.