A method of forming a semiconductor device includes: forming, in a first device region of the semiconductor device, first nanostructures over a first fin that protrudes above a substrate; forming, in a second device region of the semiconductor device, second nanostructures over a second fin that protrudes above the substrate, where the first and the second nanostructures include a semiconductor material and extend parallel to an upper surface of the substrate; forming a dielectric material around the first and the second nanostructures; forming a first hard mask layer in the first device region around the first nanostructures and in the second device region around the second nanostructures; removing the first hard mask layer from the second device region after forming the first hard mask layer; and after removing the first hard mask layer, increasing a first thickness of the dielectric material around the second nanostructures by performing an oxidization process.

A semiconductor device includes thin film transistors each having an oxide semiconductor. The oxide semiconductor has a channel region, a drain region, a source region, and low concentration regions which are lower in impurity concentration than the drain region and the source region. The low concentration regions are located between the channel region and the drain region, and between the channel region and the source region. Each of the thin film transistors has a gate insulating film on the channel region and the low concentration regions, an aluminum oxide film on a first part of the gate insulating film, the first part being located on the channel region, and a gate electrode on the aluminum oxide film and a second part of the gate insulating film, the second part being located on the low concentration regions.

A method for forming a semiconductor device structure includes removing a portion of a first dielectric layer surrounding each of a plurality of channel layers of at least a first nanosheet stack. A portion of a second dielectric layer surrounding each of a plurality of channel layers of at least a second nanosheet stack is crystallized. A dipole layer is formed on the etched first dielectric layer and the crystallized portion of the second dielectric layer. The dipole layer is diffused into the etched first dielectric layer. The crystallized portion of the second dielectric layer prevents the dipole layer form diffusing into the second dielectric layer.

The semiconductor device includes a first gate electrode, a first gate insulating film, a semiconductor film, a first electrode, a second electrode, a second gate insulating film, and a second gate electrode. The first gate insulating film is located over the first gate electrode. The semiconductor film is located over the first gate insulating film and overlaps with the first gate electrode. The first electrode and the second electrode are each located over and in contact with the semiconductor film. The second gate insulating film is located over the first electrode and the second electrode. The second gate electrode is located over the second gate insulating film and overlaps with the second electrode and the first gate electrode. The first electrode is completely exposed from the second gate electrode.

A method of forming a semiconductor device includes: forming, in a first device region of the semiconductor device, first nanostructures over a first fin that protrudes above a substrate; forming, in a second device region of the semiconductor device, second nanostructures over a second fin that protrudes above the substrate, where the first and the second nanostructures include a semiconductor material and extend parallel to an upper surface of the substrate; forming a dielectric material around the first and the second nanostructures; forming a first hard mask layer in the first device region around the first nanostructures and in the second device region around the second nanostructures; removing the first hard mask layer from the second device region after forming the first hard mask layer; and after removing the first hard mask layer, increasing a first thickness of the dielectric material around the second nanostructures by performing an oxidization process.

A semiconductor device includes a substrate including a first region and a second region, a first gate stack on the first region and including a first gate stacked insulating film and a first gate electrode on the first gate stacked insulating film, and a second gate stack on the second region and including a second gate stacked insulating film and a second gate electrode on the second gate stacked insulating film, wherein a width of the first gate stack is greater than a width of the second gate stack and the second gate stacked insulating film includes a plurality of ferroelectric material films.

Thin film transistors having double gates are described. In an example, an integrated circuit structure includes an insulator layer above a substrate. A first gate stack is on the insulator layer. A polycrystalline channel material layer is on the first gate stack. A second gate stack is on a first portion of the polycrystalline channel material layer, the second gate stack having a first side opposite a second side. A first conductive contact is adjacent the first side of the second gate stack, the first conductive contact on a second portion of the channel material layer. A second conductive contact is adjacent the second side of the second gate stack, the second conductive contact on a third portion of the channel material layer.

An embodiment of the invention may include a forkFET semiconductor structure, and the method of forming said structure. The structure may include a first FET device and a second FET device separated by a vertical dielectric pillar. The first FET device may include a first plurality of horizontal sheet channels. The second FET device may include a second plurality of horizontal sheet channels. The first plurality of horizontal sheet channels contains more horizontal sheets than the second plurality of horizontal sheet channels. This may enable adjustment of W.sub.eff for different devices on different sides of the pillar or different thicknesses of dielectrics used for the device.

According to one embodiment, a semiconductor device includes an insulating substrate, a first semiconductor layer formed of silicon and positioned above the insulating substrate, a second semiconductor layer formed of a metal oxide and positioned above the first semiconductor layer, a first insulating film formed of a silicon nitride and positioned between the first semiconductor layer and the second semiconductor layer, and a block layer positioned between the first semiconductor film and the second semiconductor layer, the block layer hydrogen diffusion of which is lower than that of the first insulating film.

Described herein are various amorphous metal thin film transistors. Embodiments of such transistors include an amorphous metal gate electrode and a channel conductor formed on a non-conducting substrate. Further embodiments of such transistors include an amorphous metal source electrode, an amorphous metal drain electrode, and a channel conductor formed on a non-conducting substrate. Methods of forming such transistors are also described.