The present disclosure provides a semiconductor device. The semiconductor device includes a substrate having a first conductive pattern and a conductive mask disposed over the first conductive pattern. The semiconductor device further includes a second conductive pattern disposed over the conductive mask, and electrically connecting with the first conductive pattern through the conductive mask. The conductive mask has a lower etch rate to a predetermined etchant than the second conductive pattern. A method for forming the semiconductor device is also provided.