A method for fabricating substrate of a semiconductor device includes the steps of: providing a first silicon layer; forming a dielectric layer on the first silicon layer; bonding a second silicon layer to the dielectric layer; removing part of the second silicon layer and part of the dielectric layer to define a first region and a second region on the first silicon layer, wherein the remaining of the second silicon layer and the dielectric layer are on the second region; and forming an epitaxial layer on the first region of the first silicon layer, wherein the epitaxial layer and the second silicon layer comprise same crystalline orientation.

Occurrence of short-channel characteristics and parasitic capacitance of a MOSFET on a SOI substrate is prevented.

A sidewall having a stacked structure obtained by sequentially stacking a silicon oxide film and a nitride film is formed on a side wall of a gate electrode on the SOI substrate. Subsequently, after an epitaxial layer is formed beside the gate electrode, and then, the nitride film is removed. Then, an impurity is implanted into an upper surface of the semiconductor substrate with using the gate electrode and the epitaxial layer as a mask, so that a halo region is formed in only a region of the upper surface of the semiconductor substrate which is right below a vicinity of both ends of the gate electrode.

Vertical field effect transistor (FET) device with tunable bandgap source/drain regions are provided, as well as methods for fabricating such vertical FET devices. For example, a vertical FET device includes a lower source/drain region formed on a substrate, a vertical semiconductor fin formed on the lower source/drain region, and an upper source/drain region formed on an upper region of the vertical semiconductor fin. The lower source/drain region and vertical semiconductor fin are formed of a first type of III-V semiconductor material. The upper source/drain region is formed of a second type of III-V semiconductor material which comprises the first type of III-V semiconductor material and at least one additional element that increases a bandgap of the second type of III-V semiconductor material of the upper source/drain region relative to a bandgap of the first type of III-V compound semiconductor material of the lower source/drain region and the vertical semiconductor fin.

A semiconductor device including a first gate structure is disposed on the semiconductor substrate. The first gate structure includes a gate dielectric layer, a layer, a first work function metal, a second work function metal, and a fill metal. A second gate structure is also disposed on the semiconductor substrate. The second gate structure includes the gate dielectric layer, a second work function metal, and the fill metal. In an embodiment, the second gate structure also includes an etch stop layer.

A method for filling gaps between structures includes forming a plurality of high aspect ratio structures adjacent to one another with gaps, forming a first dielectric layer on tops of the structures and conformally depositing a spacer dielectric layer over the structures. The spacer dielectric layer is removed from horizontal surfaces and a protection layer is conformally deposited over the structures. The gaps are filled with a flowable dielectric, which is recessed to a height along sidewalls of the structures by a selective etch process such that the protection layer protects the spacer dielectric layer on sidewalls of the structures. The first dielectric layer and the spacer dielectric layer are exposed above the height using a higher etch resistance than the protection layer to maintain dimensions of the spacer layer dielectric through the etching processes. The gaps are filled by a high density plasma fill.

A method for filling gaps between structures includes forming a plurality of high aspect ratio structures adjacent to one another with gaps, forming a first dielectric layer on tops of the structures and conformally depositing a spacer dielectric layer over the structures. The spacer dielectric layer is removed from horizontal surfaces and a protection layer is conformally deposited over the structures. The gaps are filled with a flowable dielectric, which is recessed to a height along sidewalls of the structures by a selective etch process such that the protection layer protects the spacer dielectric layer on sidewalls of the structures. The first dielectric layer and the spacer dielectric layer are exposed above the height using a higher etch resistance than the protection layer to maintain dimensions of the spacer layer dielectric through the etching processes. The gaps are filled by a high density plasma fill.

A method of forming a gate structure, including forming one or more vertical fins on a substrate; forming a bottom spacer on the substrate surface adjacent to the one or more vertical fins; forming a gate structure on at least a portion of the sidewalls of the one or more vertical fins; forming a gauge layer on at least a portion of the bottom spacer, wherein the gauge layer covers at least a portion of the gate structure on the sidewalls of the one or more vertical fins; and removing a portion of the gauge layer on the bottom spacer.

A method of forming a gate structure, including forming one or more vertical fins on a substrate; forming a bottom spacer on the substrate surface adjacent to the one or more vertical fins; forming a gate structure on at least a portion of the sidewalls of the one or more vertical fins; forming a gauge layer on at least a portion of the bottom spacer, wherein the gauge layer covers at least a portion of the gate structure on the sidewalls of the one or more vertical fins; and removing a portion of the gauge layer on the bottom spacer.

Structures and formation methods of a semiconductor device structure are provided. The semiconductor device structure includes a fin structure over a semiconductor substrate. The semiconductor device structure also includes a gate stack covering a portion of the fin structure. The semiconductor device structure further includes a spacer element over a sidewall of the gate stack. The spacer element includes a first layer and a second layer over the first layer. The dielectric constant of the first layer is greater than the dielectric constant of the second layer.

A method for forming a gate tie-down includes opening up a cap layer and recessing gate spacers on a gate structure to expose a gate conductor; forming inner spacers on the gate spacers; etching contact openings adjacent to sides of the gate structure down to a substrate below the gate structures; and forming trench contacts on sides of the gate structure. An interlevel dielectric (ILD) is deposited on the gate conductor and the trench contacts and over the gate structure. The ILD is opened up to expose the trench contact on one side of the gate structure and the gate conductor. A second conductive material provides a self-aligned contact down to the trench contact on the one side and to form a gate contact down to the gate conductor and a horizontal connection within the ILD over an active area between the gate conductor and the self-aligned contact.