| abstract |
A method for forming a semiconductor structure is provided. The method for forming the semiconductor structure includes alternately stacking first semiconductor layers and second semiconductor layers over a substrate, patterning the first semiconductor layers and the second semiconductor layers into a fin structure, removing the first semiconductor layers of the fin structure thereby forming gaps between the second semiconductor layers of the fin structure, forming a gate dielectric layer wrapping around the second semiconductor layers, forming a barrier material on the gate dielectric layer. At least a portion of the barrier material is oxidized to form a first barrier oxide. The method for forming the semiconductor structure also includes etching away the first barrier oxide, forming a work function layer to wrap around the second semiconductor layers, and forming a metal fill layer over the work function layer. |