Abstract: A method for fabricating a transistor device on a semiconductor substrate, comprising the following steps. A semiconductor substrate having a silicon surface with an overlying insulating dielectric layer is provided. The insulating dielectric layer is patterned to define hole/channel regions having predetermined widths. An amorphous silicon layer is formed having a predetermined thickness over the dielectric layer and the hole/channel regions, filling the hole/channel regions. Heating (grain growth) the amorphous silicon layer to form a planar silicon layer, comprising at least a portion of epitaxial-silicon, having a predetermined thickness, over the dielectric layer and through the hole/channel regions, filling the hole/channel regions. The planar silicon layer is patterned to expose the hole/channel regions and define transistor regions. Trenches are formed in the silicon surface adjacent the transistor regions.