Low leakage, high frequency devices and methods of manufacture are disclosed. The method of forming a device includes implanting a lateral diffusion drain implant in a substrate by a blanket implantation process. The method further includes forming a self-aligned tapered gate structure on the lateral diffusion drain implant. The method further includes forming a halo implant in the lateral diffusion drain implant, adjacent to the self-aligned tapered gate structure and at least partially under a source region of the self-aligned tapered gate structure.