GAA Semiconductor Structure With Air-Gap S/D Isolation

The patent applies segmentation by dividing the fabrication process into distinct stages: forming sacrificial layers, creating spacers, selectively removing materials, and forming gate structures. This stepwise segmentation of the manufacturing process makes the complex multi-gate device fabrication more manageable and controllable, directly addressing the manufacturing complexity challenge while achieving improved gate control.

The patent employs preliminary action by pre-forming sacrificial layers and spacers before final device fabrication. These preliminary structures guide subsequent processing steps and enable precise positioning of critical features at scaled dimensions. The preliminary sacrificial layers and spacer formations establish a framework that simplifies later manufacturing steps, allowing efficient production of miniaturized devices without proportionally increasing complexity.

The patent implements local quality by enabling different numbers of active nanostructures in different device regions through selective removal processes. The sacrificial layer and spacer structures allow precise local control over which nanostructures remain active versus which are removed. This local differentiation achieves optimized device performance across various regions while the self-aligned nature of the process minimizes the manufacturing precision burden.