A method for fabricating a MOS transistor includes: forming a gate dielectric material layer over a substrate; forming a lower gate electrode material layer over the gate dielectric material layer; performing a first ion bombardment process of bombarding the lower gate electrode material layer with first ions; forming an intermediate gate electrode material layer including an amorphous silicon layer over the lower gate electrode material layer; forming an upper gate electrode material layer over the intermediate gate electrode material layer; performing a second ion bombardment process for bombarding the upper gate electrode material layer with second ions; and forming silicide layers in the lower gate electrode material layer and the upper gate electrode material layer to form a lower gate electrode layer and an upper gate electrode layer.

In a semiconductor device according to an embodiment, a thickness of a semiconductor layer of an SOI substrate on which a field effect transistor constituting an analog circuit is formed is set to 2 nm or more and 24 nm or less.

The present disclosure describes a method for forming (i) input/output (I/O) fin field effect transistors (FET) with polysilicon gate electrodes and silicon oxide gate dielectrics integrated and (ii) non-I/O FETs with metal gate electrodes and high-k gate dielectrics. The method includes depositing a silicon oxide layer on a first region of a semiconductor substrate and a high-k dielectric layer on a second region of the semiconductor substrate; depositing a polysilicon layer on the silicon oxide and high-k dielectric layers; patterning the polysilicon layer to form a first polysilicon gate electrode structure on the silicon oxide layer and a second polysilicon gate electrode structure on the high-k dielectric layer, where the first polysilicon gate electrode structure is wider than the second polysilicon gate electrode structure and narrower than the silicon oxide layer. The method further includes replacing the second polysilicon gate electrode structure with a metal gate electrode structure.

A semiconductor structure includes: a channel layer; an active layer over the channel layer, wherein the active layer is configured to form a two-dimensional electron gas (2DEG) to be formed in the channel layer along an interface between the channel layer and the active layer; a gate electrode over a top surface of the active layer; and a source/drain electrode over the top surface of the active layer; wherein the active layer includes a first layer and a second layer sequentially disposed therein from the top surface to a bottom surface of the active layer, and the first layer possesses a higher aluminum (Al) atom concentration compared to the second layer. An HEMT structure and an associated method are also disclosed.

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.

Aspects of the disclosure provide a semiconductor device and a method for forming the semiconductor device. The semiconductor device includes a plurality of nanostructures stacked over a substrate in a vertical direction, a source/drain terminal adjoining the plurality of nanostructures, and a gate structure around the plurality of nanostructures. The gate structure includes a metal cap connecting adjacent two of the plurality of nanostructures and a metal layer partially surrounding the plurality of nanostructures.

Aspects of the present inventive concept provide a semiconductor device capable of enhancing performance and reliability through source/drain engineering in a transistor including an oxide semiconductor layer. The semiconductor device includes a substrate, a metal oxide layer disposed on the substrate, a source/drain pattern being in contact with the metal oxide layer and including a portion protruding from a top surface of the metal oxide layer, a plurality of gate structures disposed on the metal oxide layer with the source/drain pattern interposed therebetween and each including gate spacers and an insulating material layer, the insulating material layer being in contact with the metal oxide layer, and not extending along a top surface of the source/drain pattern, and a contact disposed on the source/drain pattern, the contact being connected to the source/drain pattern.

A semiconductor device includes a semiconductor substrate, an emitter region, a base region and multiple accumulation areas, and an upper accumulation area in the multiple accumulation areas is in direct contact with a gate trench section and a dummy trench section, in an arrangement direction that is orthogonal to a depth direction and an extending direction, a lower accumulation area furthest from the upper surface of the semiconductor substrate in the multiple accumulation areas has: a gate vicinity area closer to the gate trench section than the dummy trench section in the arrangement direction; and a dummy vicinity area closer to the dummy trench section than the gate trench section in the arrangement direction, and having a doping concentration of the first conductivity type lower than that of the gate vicinity area.

The present disclosure provides one embodiment of a semiconductor structure. The semiconductor structure includes a first active region and a second fin active region extruded from a semiconductor substrate; an isolation featured formed in the semiconductor substrate and being interposed between the first and second fin active regions; a dielectric gate disposed on the isolation feature; a first gate stack disposed on the first fin active region and a second gate stack disposed on the second fin active region; a first source/drain feature formed in the first fin active region and interposed between the first gate stack and the dielectric gate; a second source/drain feature formed in the second fin active region and interposed between the second gate stack and the dielectric gate; a contact feature formed in a first inter-level dielectric material layer and landing on the first and second source/drain features and extending over the dielectric gate.

A semiconductor structure includes at least one stacked fin structure, a gate and a source/drain. At least one stacked fin structure is located on a substrate, wherein the stacked fin structure includes a first fin layer and a second fin layer, and a fin dielectric layer is sandwiched by the first fin layer and the second fin layer. The gate is disposed over the stacked fin structure. The source/drain is disposed directly on the substrate and directly on sidewalls of the whole stacked fin structure. The present invention provides a semiconductor process formed said semiconductor structure.