Patent attributes
A semiconductor device structure and a method for forming a semiconductor device structure are provided. The semiconductor device structure includes a semiconductor fin over a substrate and multiple semiconductor nanostructures suspended over the semiconductor fin. The semiconductor device structure also includes a gate stack extending across the semiconductor fin, and the gate stack wraps around each of the semiconductor nanostructures. The semiconductor device structure further includes a first epitaxial structure and a second epitaxial structure sandwiching the semiconductor nanostructures. Each of the first epitaxial structure and the second epitaxial structure extends exceeding a top surface of the semiconductor fin. In addition, the semiconductor device structure includes an isolation structure between the semiconductor fin and the gate stack. The isolation structure further extends exceeding opposite sidewalls of the first epitaxial structure.