Abstract: Ruthenium of a metal gate (MG) and/or a middle end of line (MEOL) structure is annealed to reduce, or even eliminate, seams after the ruthenium is deposited. Because the annealing reduces (or removes) seams in deposited ruthenium, electrical performance is increased because resistivity of the MG and/or the MEOL structure is decreased. Additionally, for MGs, the annealing generates a more even deposition profile, which results in a timed etching process producing a uniform gate height. As a result, more of the MGs will be functional after etching, which increases yield during production of the electronic device.

Abstract: A semiconductor device structure and a formation method are provided. The method includes forming a fin structure over a substrate, and the fin structure has multiple sacrificial layers and multiple semiconductor layers laid out alternately. The method also includes removing the sacrificial layers to release multiple semiconductor nanostructures made up of remaining portions of the semiconductor lavers. The method further includes forming a gate dielectric layer to wrap around the semiconductor nanostructures and forming a first metal-containing layer over the gate dielectric layer to wrap around the semiconductor nanostructures. In addition, the method includes introducing oxygen-containing plasma on the first metal-containing layer to transform an upper portion of the first metal-containing layer into a metal oxide layer. The method includes forming a second metal-containing layer over the metal oxide layer.