Semiconductor structures and methods are provided. A method according to the present disclosure includes forming a first channel member, a second channel member directly over the first channel member, and a third channel member directly over the second channel member, depositing a first metal layer around each of the first channel member, the second channel member, and the third channel member, removing the first metal layer from around the second channel member and the third channel member while the first channel member remains wrapped around by the first metal layer, after the removing of the first metal layer, depositing a second metal layer around the second channel member and the third channel member, removing the second metal layer from around the third channel member, and after the removing of the second metal layer, depositing a third metal layer around the third channel member.

A transistor structure is disclosed. The transistor structure includes a dielectric layer that has a thinner portion over a first doped well and a second doped well, and a thicker portion adjacent the thinner portion and over the second doped well. The thicker portion has a height greater than the thinner portion above the doped wells. The transistor includes a first gate structure on the thinner portion and a second gate structure on the thicker portion of the dielectric layer. The transistor may include a third gate structure on the thicker portion.

Aspects of the present disclosure provide a vertical channel 3D semiconductor device sand a method for fabricating the same. The 3D semiconductor devices may have vertical channels of the same or different epitaxially grown doped materials. Sidewall structures are formed around each vertical channel by masking and etching material between the vertical channels. A dielectric layer in each of the sidewalls is etched down to the vertical channel and a gate electrode structure is formed in the opening. The gate electrode structure may include an interfacial oxide, a high-K layer and alternating metal layers. Local interconnects connect to the metal of the gate structure.

A semiconductor structure and a forming method thereof are provided. The forming method of the semiconductor structure comprises: providing a substrate comprising a first area for forming a P-channel Metal Oxide Semiconductor (PMOS) transistor and a second area for forming an N-channel Metal Oxide Semiconductor (NMOS) transistor; forming a channel layer on the surface of the first area of the substrate; adjusting the oxidation rate of the channel layer to reduce the difference between the oxidation rate of the channel layer and the oxidation rate of the substrate; and oxidizing the surfaces of the channel layer and the second area of the substrate to form a first transition oxide layer covering the surface of the channel layer and a second transition oxide layer covering the surface of the second area of the substrate.

A semiconductor device comprises a substrate, a first active pattern on the substrate and extending in a first direction, a second active pattern extending in the first direction spaced apart from the substrate, a gate electrode extending in a second direction surrounding the first and second active patterns, and a high dielectric film between the first and second active patterns and the gate electrode. The gate electrode includes first and second work function adjusting films surrounding the high dielectric film on the first and second active patterns, and a filling conductive film surrounding the first and second work function adjusting films. The first and second work function adjusting films include first and second work function conductive films, each of which includes a first metal film. A thickness of the first metal film of the first work function conductive film is greater than that of the second work function conductive film.

A semiconductor device may include a plurality of first active fins protruding from a substrate, each of the first active fins extending in a first direction; a second active fin protruding from the substrate; and a plurality of respective first fin-field effect transistors (finFETs) on the first active fins. Each of the first finFETs includes a first gate structure extending in a second direction perpendicular to the first direction, and the first gate structure includes a first gate insulation layer and a first gate electrode. The first finFETs are formed on a first region of the substrate and have a first metal oxide layer as the first gate insulation layer, and a second finFET is formed on the second active fin on a second region of the substrate, and the second finFET does not include a metal oxide layer, but includes a second gate insulation layer that has a bottom surface at the same plane as a bottom surface of the first metal oxide layer.

A semiconductor device includes a semiconductor substrate having first and second regions therein, a first lower semiconductor pattern, which protrudes from the semiconductor substrate in the first region and extends in a first direction across the semiconductor substrate, and a first gate electrode, which extends across the first lower semiconductor pattern and the semiconductor substrate in a second direction. A plurality of semiconductor sheet patterns are provided, which are spaced apart from each other in a third direction to thereby define a vertical stack of semiconductor sheet patterns, on the first lower semiconductor pattern. A first gate insulating film is provided, which separates the plurality of semiconductor sheet patterns from the first gate electrode. A second lower semiconductor pattern is provided, which protrudes from the semiconductor substrate in the second region. A plurality of wire patterns are provided, which are spaced apart from each other on the second lower semiconductor pattern. A second gate insulating film is wrapped around each of the plurality of wire patterns.

A semiconductor integrated circuit device including a substrate with a first element region of a P type and a second element region of an N type, a channel active region that extends in the first element region or the second element region, the channel active region including a plurality of channels, a plurality of gate lines that extend in a second direction intersecting and include a gate metal layer, and a gate insulating film in contact with the gate metal layer, a plurality of first spacers on opposite side portions of respective ones of the gate lines, and a plurality of source/drain regions that are between ones of the plurality of gate lines. The channel active region includes a first channel directly on the substrate, and a second channel spaced apart from the first channel and extends into the gate metal layer.

A semiconductor device includes a first transistor and a second transistor. The first transistor includes: a first source and a first drain separated by a first distance, a first semiconductor structure disposed between the first source and first drain, a first gate electrode disposed over the first semiconductor structure, and a first dielectric structure disposed over the first gate electrode. The first dielectric structure has a lower portion and an upper portion disposed over the lower portion and wider than the lower portion. The second transistor includes: a second source and a second drain separated by a second distance greater than the first distance, a second semiconductor structure disposed between the second source and second drain, a second gate electrode disposed over the second semiconductor structure, and a second dielectric structure disposed over the second gate electrode. The second dielectric structure and the first dielectric structure have different material compositions.

A method of forming a complementary metal oxide semiconductor (CMOS) device is provided. The method includes forming a separate gate structure on each of a pair of vertical fins, wherein the gate structures include a gate dielectric layer and a gate metal layer, and forming a protective liner layer on the gate structures. The method further includes heat treating the pair of gate structures, and replacing the protective liner layer with an encapsulation layer. The method further includes exposing a portion of the gate dielectric layer by recessing the encapsulation layer. The method further includes forming a top source/drain on the top surface of one of the pair of vertical fins, and subjecting the exposed portion of the gate dielectric layer to a second heat treatment conducted in an oxidizing atmosphere.