Embodiments of the present invention include semiconductor devices that can be made with relatively low resistance, and methods of forming the semiconductor devices. A resistance reducing layer is formed between a polysilicon layer and a metal layer. As a result, an interface resistance between the polysilicon layer and the metal layer is greatly reduced and a distribution of the interface resistance is very uniform. As a result, a conductive structure including the resistance reducing layer has a greatly reduced sheet resistance to improve electrical characteristics of a semiconductor device having the conductive structure.