Semiconductor devices and methods of forming the same include forming a first stack of nanosheets in a first region, the first stack of nanosheets including upper first nanosheets and lower first nanosheets. A second stack of nanosheets is formed in a second region, the second stack of nanosheets including upper second nanosheets and lower second nanosheets. A lower gate cut structure is formed between the lower first nanosheets and the lower second nanosheets. A gate stack is formed on the first and second stack of nanosheets after forming the lower gate cut structure. An upper gate cut structure is formed after forming the gate stack.

A semiconductor structure is provided. The semiconductor structure includes: a base substrate having an opening; and a first gate layer formed in the opening. In the first gate layer closes a top of the opening and the first gate layer includes at least one void. The semiconductor structure further includes a second gate layer formed on the first gate layer. An atomic radius of the material of the second gate layer is smaller than gaps among atoms of the material of the first gate layer and the void is filled by atoms of one of the material of the first gate layer and the material of the second gate layer.

Apparatus and circuits with dual threshold voltage transistors and methods of fabricating the same are disclosed. In one example, a semiconductor structure is disclosed. The semiconductor structure includes: a substrate; a first layer comprising a first III-V semiconductor material formed over the substrate; a first transistor formed over the first layer, and a second transistor formed over the first layer. The first transistor comprises a first gate structure comprising a first material, a first source region and a first drain region. The second transistor comprises a second gate structure comprising a second material, a second source region and a second drain region. The first material is different from the second material.

A multi-gate semiconductor device includes a plurality of nanostructures vertically stacked over a substrate, a gate dielectric layer wrapping around the plurality of nanostructures, a gate conductive structure over the gate dielectric layer, and a first insulating spacer alongside the gate conductive structure and over the plurality of nanostructures. The first insulating spacer is in direct contact with the gate conductive structure and the gate dielectric layer.

Apparatus and circuits including transistors with different threshold voltages and methods of fabricating the same are disclosed. In one example, a semiconductor structure is disclosed. The semiconductor structure includes: a substrate; an active layer that is formed over the substrate and comprises a plurality of active portions; a polarization modulation layer comprising a plurality of polarization modulation portions each of which is disposed on a corresponding one of the plurality of active portions; and a plurality of transistors each of which comprises a source region, a drain region, and a gate structure formed on a corresponding one of the plurality of polarization modulation portions. The transistors have at least three different threshold voltages.

A semiconductor structure is formed using a nanosheet stack that is over a semiconductor substrate. The semiconductor structure includes multiple layers of work function that surround each channel of a plurality of channels in the nanosheet stack and are on the semiconductor substrate under the nanosheet stack. Adjacent layers of the work function metal in the semiconductor structure are separated by an oxide material. The oxide material is a very thin layer of an oxide with a thickness of several angstroms or less. The semiconductor structure includes an n-type work function metal that is over an outer layer of the multiple layers of the work function metal. The n-type work function metal can be an aluminum containing metal that is covered by a capping material under a gate electrode material.

The structure of a semiconductor device with isolation structures between FET devices and a method of fabricating the semiconductor device are disclosed. A method of fabricating the semiconductor device includes forming a fin structure on a substrate and forming polysilicon gate structures with a first threshold voltage on first fin portions of the fin structure. The method further includes forming doped fin regions with dopants of a first type conductivity on second fin portions of the fin structure, doping at least one of the polysilicon gate structures with dopants of a second type conductivity to adjust the first threshold voltage to a greater second threshold voltage, and replacing at least two of the polysilicon gate structures adjacent to the at least one of the polysilicon gate structures with metal gate structures having a third threshold voltage less than the first and second threshold voltages

A CFET (complementary field effect transistor) structure including a substrate, a first CFET formed above the substrate, and a second CFET formed above the substrate. The first CFET includes a top FET and a bottom FET. The top FET and bottom FET of the first CFET include at least one nanosheet channel. A gate affiliated with the first CFET and the second CFET devices includes a continuous horizontal dielectric over the entire length of the gate. The top FET of each CFET has a first polarity. The bottom FET of each a CFET comprises a second polarity. The top FET of the first CFET includes a first work function metal, and the top FET of the second CFET includes a second work function metal.

A semiconductor device includes a substrate including PMOSFET and NMOSFET regions; and first/second transistors on the PMOSFET/NMOSFET regions, respectively, wherein the first transistor includes a first gate dielectric layer on the substrate; a first lower metal pattern on the first gate dielectric layer; a second lower metal pattern on the first lower metal pattern; and a first intermediate pattern between the first and second lower metal patterns, the second transistor includes a second gate dielectric layer on the substrate; a third lower metal pattern on the second gate dielectric layer; and a second intermediate pattern between the second gate dielectric layer and the third lower metal pattern, the first and second intermediate patterns each include lanthanum, the first to third lower metal patterns each include a metal nitride, and a thickness of the first lower metal pattern is greater than a thickness of the third lower metal pattern.

A method of fabricating a device includes providing a fin extending from a substrate, the fin having a plurality of semiconductor layers and a first distance between each adjacent semiconductor layers. The method further includes providing a dielectric fin extending from the substrate where the dielectric fin is adjacent to the plurality of semiconductor layers and there is a second distance between an end of each of the semiconductor layers and a first sidewall of the dielectric fin. The second distance is greater than the first distance. Depositing a dielectric layer over the semiconductor layers and over the first sidewall of the dielectric fin. Forming a first metal layer over the dielectric layer on the semiconductor layers and on the first sidewall of the dielectric fin, wherein portions of the first metal layer disposed on and interposing adjacent semiconductor layers are merged together. Finally removing the first metal layer.