An LDMOS is formed with a field plate over the n− drift region, coplanar with the gate stack, and having a higher work function than the gate stack. Embodiments include forming a first conductivity type well, having a source, surrounded by a second conductivity type well, having a drain, in a substrate, forming first and second coplanar gate stacks on the substrate over a portion of the first well and a portion of the second well, respectively, and tuning the work functions of the first and second gate stacks to obtain a higher work function for the second gate stack. Other embodiments include forming the first gate stack of a high-k metal gate and the second gate stack of a field plate on a gate oxide layer, forming the first and second gate stacks with different gate electrode materials on a common gate oxide, and forming the gate stacks separated from each other and with different gate dielectric materials.