Abstract: A semiconductor device with a barrier layer between a gate structure and gate spacer layers, and a method of fabricating the same are disclosed. The a method includes forming a fin structure on a substrate, forming a polysilicon structure on the fin structure, performing a nitridation operation to form a barrier layer on the polysilicon structure and the fin structure, forming gate spacer layers on the barrier layer, forming a source/drain region in the fin structure and adjacent to the barrier layer, annealing the gate spacer layers, and replacing the polysilicon structure with a gate structure.

Abstract: Embodiments include a method and device resulting from the method, including using a radical oxidation process to oxidize a spacer layer which lines the opening after removing a dummy gate electrode. The oxidized layer is removed by an etching process. An STI region disposed below the dummy gate electrode may be partially etched.

Abstract: Semiconductor structures and methods for manufacturing the same are provided. The method for manufacturing the semiconductor structure includes forming a fin structure protruding from a substrate, and the fin structure includes first semiconductor material layers and second semiconductor material layers alternately stacked. The method also includes forming a dummy gate structure across the fin structure and forming a gate spacer on a sidewall of the dummy gate structure. The method also includes partially oxidizing the gate spacer to form an oxide layer and removing the oxide layer to form a modified gate spacer. The method also includes removing the first semiconductor material layers to form gaps and forming a gate structure in the gaps to wrap around the second semiconductor material layers and over the second semiconductor material layers to cover the modified gate spacer.