TRENCH GATE MOS SEMICONDUCTOR DEVICE

摘要

A trench MOS-gated device (200) comprises a doped monocrystalline semiconductor substrate (201) that includes an upper layer (201a) and is of a first conductivity type. An extended trench (202) in the substrate in the upper layer comprises two segments (203,204) having differing widths relative to one another: a bottom segment (204) of lesser width filled with a dielectric material (209), and an upper (203) segment of greater width lined with a dielectric material (205,206) and substantially filled with a conductive material (207), the filled upper segment of the trench forming a gate region (208). An extended doped zone (215) of a second opposite conductivity type extends from an upper surface (212) into the upper layer (210a) of the substrate only on one side of the trench (202), and a doped well region (210) of the second conductivity type overlying a drain zone (211) of the first conductivity type is disposed in the upper layer (201a) on the opposite side of the trench.