Patent ID: RE45165

Claim:
A method for forming a semiconductor device, comprising: forming a hard mask layer on a semiconductor substrate; patterning the hard mask layer to form a plurality of openings; etching the substrate through the plurality of openings of the hard mask layer to form a plurality of trenches separating a plurality of semiconductor mesas, wherein each of the plurality of semiconductor mesas is formed to have a top portion having sidewalls of a first slope and a bottom portion having sidewalls of a second slope, and wherein each of the plurality of trenches is formed to have a top trench portion having a sidewall of the first slope and a bottom trench portion having a sidewall of the second slope, and wherein the first slope is different from the second slope; partially filling the plurality of trenches with a dielectric material; removing the hard mask layer; and forming a plurality of multiple-gate features, each multiple-gate feature being in contact with a top surface and sidewalls of at least one of the plurality of semiconductor mesas.