Semiconductor devices with transistors having different gate dielectric materials and methods of manufacture thereof are disclosed. One embodiment includes a semiconductor device including a workpiece, the workpiece including a first region and a second region proximate the first region. A first transistor is disposed in the first region of the workpiece, the first transistor having at least two first gate electrodes. A first gate dielectric is disposed proximate each of the at least two first gate electrodes, the first gate dielectric comprising a first material. A second transistor is disposed in the second region of the workpiece, the second transistor having at least two second gate electrodes. A second gate dielectric is disposed proximate each of the at least two second gate electrodes, the second gate dielectric comprising a second material. The second material is different than the first material.