Semiconductor devices with replacement gate electrodes are formed with different materials in the work function layers. Embodiments include forming first and second removable gates on a substrate, forming first and second pairs of spacers on opposite sides of the first and second removable gates, respectively, forming a hardmask layer over the second removable gate, removing the first removable gate, forming a first cavity between the first pair of spacers, forming a first work function material in the first cavity, removing the hardmask layer and the second removable gate, forming a second cavity between the second pair of spacers, and forming a second work function material, different from the first work function material, in the second cavity.