A method for manufacturing a semiconductor device comprises forming a first diffusion stop layer on a bulk semiconductor substrate, forming a doped semiconductor layer on the first diffusion stop layer, forming a second diffusion stop layer on the doped semiconductor layer, forming a fin layer on the doped semiconductor layer, patterning the first and second diffusion stop layers, the doped semiconductor layer, the fin layer and a portion of the bulk substrate, oxidizing the doped semiconductor layer to form an oxide layer, and forming a dielectric on the bulk substrate adjacent the patterned portion of the bulk substrate, the patterned first diffusion stop layer and the oxide layer.