Methods of manufacturing a conductive feature and a package are provided. One of the methods includes the following steps. A seed layer is formed. A conductive pattern is formed over the seed layer. The seed layer and the conductive pattern include a same material. A dry etch process is performed to partially remove the seed layer exposed by the conductive pattern, to form a seed layer pattern. A plasma treatment process is performed on the seed layer pattern and the conductive pattern thereon, wherein the step of partially removing the seed layer and the step of performing the plasma treatment process are in-situ processes.