A field effect transistor device includes a first conductive channel disposed on a substrate, a second conductive channel disposed on the substrate, a first gate stack formed on the first conductive channel, the first gate stack including a metallic layer having a first oxygen content, a second gate stack a formed on the second conductive channel, the second gate stack including a metallic layer having a second oxygen, an ion doped source region connected to the first conductive channel and the second conductive channel, and an ion doped drain region connected to the first conductive channel and the second conductive channel.