TRANSISTOR WITH CHANNEL-SYMMETRIC GATE

transistor structures with gate material self-aligned to underlying channel material. a channel mask material employed for patterning channel material is retained during selective formation of a second mask material upon exposed surfaces of gate material. the channel mask material is then thinned to expose a sidewall of adjacent gate material. the exposed gate material sidewall is laterally recessed to expand an opening beyond an edge of underlying channel material. a third mask material may be formed in the expanded opening to protect an underlying portion of gate material during a gate etch that forms a trench bifurcating the underlying portion of gate material from an adjacent portion of gate material. the underlying portion of gate material extends laterally beyond the channel material by an amount that is substantially symmetrical about a centerline of the channel material and this amount has a height well controlled relative to the channel material.