US Patent 11908740 Semiconductor structure with doped via plug

A semiconductor structure is provided. The semiconductor structure includes a gate structure over a substrate. The semiconductor structure also includes source/drain structures on opposite sides of the gate structure. The semiconductor structure also includes a dielectric layer over the gate structure and the source/drain structures. The semiconductor structure also includes a via plug passing through the dielectric layer and including a first group IV element. The dielectric layer includes a second group IV element, a first compound, and a second compound, and the second compound includes elements in the first compound and the first group IV element.