Patent attributes
A recessed gate FET device includes a substrate having an upper and lower portions, the lower portion having a reduced concentration of dopant material than the upper portion; a trench-type gate electrode defining a surrounding channel region and having a gate dielectric material layer lining and including a conductive material having a top surface recessed to reduce overlap capacitance with respect to the source and drain diffusion regions formed at an upper substrate surface at either side of the gate electrode. There is optionally formed halo implants at either side of and abutting the gate electrode, each halo implants extending below the source and drain diffusions into the channel region. Additionally, highly doped source and drain extension regions are formed that provide a low resistance path from the source and drain diffusion regions to the channel region. The recessed gate FET device suppresses short channel effects and exhibits improved threshold voltage (Vt) characteristics at corners of the trench bottom.
