A method includes forming a metal layer over a substrate; forming a dielectric layer over the metal layer; removing a first portion of the dielectric layer to expose a first portion of the metal layer, while a second portion of the dielectric layer remains on the metal layer; selectively forming a first inhibitor on the second portion of the dielectric layer, while the metal layer is free of coverage by the first inhibitor; and selectively depositing a first hard mask on the exposed first portion of the metal layer, while the first inhibitor is free of coverage by the first hard mask.