Methods of fabricating a semiconductor device including a metal gate transistor and a resistor are provided. A method includes providing a substrate including a transistor device region and an isolation region, forming a dummy gate over the transistor device region and a resistor over the isolation region, and implanting the resistor with a dopant. The method further includes wet etching the dummy gate to remove the dummy gate, and then forming a metal gate over the transistor device region to replace the dummy gate.