A work function metal gate device includes a gate, a drift region, a source, a drain and a first isolation structure. The gate includes a convex stair-shaped work function metal stack or a concave stair-shaped work function metal stack disposed on a substrate. The drift region is disposed in the substrate below a part of the gate. The source is located in the substrate and the drain is located in the drift region beside the gate. The first isolation structure is disposed in the drift region between the gate and the drain.

A MOSFET fabricated in a semiconductor substrate, includes: a gate oxide region formed atop the semiconductor substrate; a gate polysilicon region formed on the gate oxide region; a source region of a first doping type formed in the semiconductor substrate and located at a first side of the gate polysilicon region; and a drain region of the first doping type formed in the semiconductor substrate and located at a second side of the gate polysilicon region. The gate polysilicon region has a first sub-region of the first doping type, a second sub-region of the first doping type, and a third sub-region of a second doping type, wherein the first sub-region is laterally adjacent to the source region, the second sub-region is laterally adjacent to the drain region, and the third sub-region is formed laterally between the first and second sub-regions.

A semiconductor device, and a method of fabricating the semiconductor device including forming on a substrate a device isolation layer defining a plurality of active regions; and forming a plurality of gate lines intersecting the active regions and buried in the substrate. The forming of the gate lines includes forming on the substrate a trench that intersects the active regions; forming a work-function control layer on a sidewall and a bottom surface of the trench; forming a conductive layer on the work-function control layer; sequentially forming a barrier layer and a source layer on the work-function control layer and the conductive layer, the source layer including a work-function control element; and diffusing the work-function control element from the source layer into an upper portion of the work-function control layer.

A method includes forming an etching mask, which includes forming a bottom anti-reflective coating over a target layer, forming an inorganic middle layer over the bottom anti-reflective coating, and forming a patterned photo resist over the inorganic middle layer. The patterns of the patterned photo resist are transferred into the inorganic middle layer and the bottom anti-reflective coating to form a patterned inorganic middle layer and a patterned bottom anti-reflective coating, respectively. The patterned inorganic middle layer is then removed. The target layer is etched using the patterned bottom anti-reflective coating to define a pattern in the target layer.

A semicondcutor device, and a method of fabricating the semiconductor device including forming on a substrate a device isolation layer defining a plurality of active regions; and forming a plurality of gate lines intersecting the active regions and buried in the substrate. The forming of the gate lines includes forming on the substrate a trench that intersects the active regions; forming a work-function control layer on a sidewall and a bottom surface of the trench; forming a conductive layer on the work-function control layer; sequentially forming a barrier layer and a source layer on the work-function control layer and the conductive layer, the source layer including a work-function control element; and diffusing the work-function control element from the source layer into an upper portion of the work-function control layer.

A structure of field-effect transistor includes a silicon layer of a silicon-on-insulator structure. A gate structure layer in a line shape is disposed on the silicon layer, wherein the gate structure layer includes a first region and a second region abutting to the first region. Trench isolation structures in the silicon layer are disposed at two sides of the gate structure layer, corresponding to the second region. The second region of the gate structure layer is disposed on the silicon layer and overlaps with the trench isolation structure. A source region and a drain region are disposed in the silicon layer at the two sides of the gate structure layer, corresponding to the first region. The second region of the gate structure layer includes a conductive-type junction portion.

A structure of field-effect transistor includes a silicon layer of a silicon-on-insulator structure. A gate structure layer in a line shape is disposed on the silicon layer, wherein the gate structure layer includes a first region and a second region abutting to the first region. Trench isolation structures in the silicon layer are disposed at two sides of the gate structure layer, corresponding to the second region. The second region of the gate structure layer is disposed on the silicon layer and overlaps with the trench isolation structure. A source region and a drain region are disposed in the silicon layer at the two sides of the gate structure layer, corresponding to the first region. The second region of the gate structure layer includes a conductive-type junction portion.

An integrated chip includes a substrate, an isolation structure and a poly gate structure. The isolation structure includes dielectric materials within the substrate and having sidewalls defining an active region. The active region has a channel region, a source region, and a drain region separated from the source region by the channel region along a first direction. The source region has a first width along a second direction perpendicular to the first direction, the drain region has a second width along the second direction, and the channel region has a third width along the second direction and larger than the first and second widths. The poly gate structure extends over the channel region. The poly gate structure includes a first doped region having a first type of dopants and a second doped region having a second type of dopants. The second type is different from the first type.

A method of manufacturing a semiconductor device is provided. A precursor structure is formed, in which the precursor structure includes a patterned substrate having at least one trench therein, an oxide layer covering the patterned substrate, and a nitride layer on the oxide layer and exposing a portion of the oxide layer in the trench. A first barrier layer and a first gate structure is formed on the oxide layer. A portion of the first barrier layer is removed with an etchant including CF.sub.4, C.sub.2F.sub.6, C.sub.3F.sub.8, C.sub.4F.sub.8, F.sub.2, NF.sub.3, SF.sub.6, CHF.sub.3, HF, COF.sub.2, ClF.sub.3 or H.sub.2O.sub.2 to expose a sidewall of the oxide layer. A second barrier layer is formed on the first gate structure and the oxide layer. A portion of the second barrier layer is removed with the etchant. A second gate structure is formed on the second barrier layer.

An embodiment of the invention may include a method for of forming a semiconductor device and the resulting device. The method may include forming a gate dielectric on a gate region of a substrate. The method may include forming an inner dummy gate on a first portion of the gate dielectric. The method may include forming an outer dummy gate adjacent to the inner dummy gate on a second portion of the gate dielectric. The method may include forming spacers adjacent to the outer dummy gate. The method may include removing the outer dummy gate and depositing a first work function metal. The method may include removing the inner dummy gate and depositing a second work function metal.