The present disclosure provides a semiconductor device structure with conductive plugs of different aspect ratios and manganese-containing lining layer and a method for preparing the same. The semiconductor device structure includes a substrate having a pattern-dense region and a pattern-loose region; a first conductive layer disposed over the substrate; a first dielectric layer disposed over the first conductive layer; a first conductive plug and a second conductive plug disposed in the first dielectric layer; wherein the first conductive plug and the second conductive plug comprises copper (Cu) and are separated from the first dielectric layer by the a first lining layer comprising manganese (Mn); wherein the first conductive plug and the second conductive plug have different aspect ratios.