A method of fabricating a semiconductor device, comprises steps of forming a common contact hole for a first conductivity-type region and a second conductivity-type region, implanting an impurity in at least one of the first conductivity-type region and the second conductivity-type region, and forming a shared contact plug by filling an electrical conducting material in the contact hole, wherein in the implanting step, an impurity is implanted in at least one of the first conductivity-type region and the second conductivity-type region such that the first conductivity-type region and the shared contact plug are brought into ohmic contact with each other, and the second conductivity-type region and the shared contact plug are brought into ohmic contact with each other.