A semiconductor device including a hybrid contact scheme for stacked FET is disclosed with integration of a BSPDN. A double-sided (both frontside and backside of the wafer) contact scheme with buried power rail (BPR) and backside power distribution network (BSPDN) provides optimum contact and interconnect. The stacked FET could include, for example, FINFET over FINFET, FINFET over nanosheet, or nanosheet over nanosheet.

A semiconductor device structure is provided. The semiconductor device structure includes a substrate having a first fin structure. The semiconductor device structure includes a first source/drain structure over the first fin structure. The semiconductor device structure includes a first dielectric layer over the first source/drain structure and the substrate. The semiconductor device structure includes a first conductive contact structure in the first dielectric layer and over the first source/drain structure. The semiconductor device structure includes a second dielectric layer over the first dielectric layer and the first conductive contact structure. The semiconductor device structure includes a first conductive via structure passing through the second dielectric layer and connected to the first conductive contact structure. The first conductive via structure has a first substantially strip shape in a top view of the first conductive via structure.

A semiconductor device with different isolation structures and a method of fabricating the same are disclosed. The a method includes forming first and second fin structures on a substrate, forming a dummy fin structure on the substrate and between the first and second fin structures, forming a polysilicon structure on the dummy fin structure, forming source/drain regions on the first and second fin structures, and replacing the polysilicon structure with a dummy gate structure. A top portion of the dummy gate structure is formed wider than a bottom portion of the dummy gate structure.

A semiconductor structure is disclosed that includes a first conductive line, a first conductive segment, a second conductive segment, and a gate. The first conductive segment is electrically coupled to the first conductive line through a conductive via. The second conductive segment is configured to electrically couple the first conductive segment with a third conductive segment disposed over an active area. The gate is disposed under the second conductive segment and disposed between first conductive segment and the third conductive segment. The first conductive line and the second conductive segment are disposed at two sides of the conductive via respectively. A length of the first conductive segment is greater than a length of the third conductive segment.

A method includes forming a first and a second contact opening to reveal a first and a second source/drain region, respectively, forming a mask layer having a first and a second portion in the first and the second contact openings, respectively, forming a first and a second sacrificial ILD in the first and the second contact openings, respectively, removing the first sacrificial ILD from the first contact opening, filling a filler in the first contact opening, and etching the second sacrificial ILD. The filler protects the first portion of the mask layer from being etched. An ILD is formed in the second contact opening and on the second portion of the mask layer. The filler and the first portion of the mask layer are removed using a wet etch to reveal the first contact opening. A contact plug is formed in the first contact opening.

In a gate last metal gate process for forming a transistor, a dielectric layer is formed over an intermediate transistor structure, the intermediate structure including a dummy gate electrode, typically formed of polysilicon. Various processes, such as patterning the polysilicon, planarizing top layers of the structure, and the like can remove top portions of the dielectric layer, which can result in decreased control of gate height when a metal gate is formed in place of the dummy gate electrode, decreased control of fin height for finFETs, and the like. Increasing the resistance of the dielectric layer to attack from these processes, such as by implanting silicon or the like into the dielectric layer before such other processes are performed, results in less removal of the top surface, and hence improved control of the resulting structure dimensions and performance.

A semiconductor structure is provided. The semiconductor structure includes a gate structure, a first source/drain structure, and a contact structure. The gate structure has a gate dielectric layer over a first fin structure. The first source/drain structure is positioned in the first fin structure and adjacent to the gate structure. The first source/drain structure includes a first epitaxial layer in contact with the top surface of the first fin structure and a second epitaxial layer over the first epitaxial layer and extending above a bottom surface of the gate dielectric layer. The contact structure extends into the first source/drain structure. The top surface of the first fin structure is between a top surface and a bottom surface of the first source/drain structure.

A semiconductor device includes a substrate, a first fin extending from the substrate, a first gate structure over the substrate and engaging the first fin, and a first epitaxial feature partially embedded in the first fin and raised above a top surface of the first fin. The semiconductor device further includes a second fin extending from the substrate, a second gate structure over the substrate and engaging the second fin, and a second epitaxial feature partially embedded in the second fin and raised above a top surface of the second fin. A first depth of the first epitaxial feature embedded into the first fin is smaller than a second depth of the second epitaxial feature embedded into the second fin.

A method of forming an integrated circuit structure includes forming a first source/drain contact plug over and electrically coupling to a source/drain region of a transistor, forming a first dielectric hard mask overlapping a gate stack, recessing the first source/drain contact plug to form a first recess, forming a second dielectric hard mask in the first recess, recessing an inter-layer dielectric layer to form a second recess, and forming a third dielectric hard mask in the second recess. The third dielectric hard mask contacts both the first dielectric hard mask and the second dielectric hard mask.

Transistor structures including a non-planar body that has an active portion comprising a semiconductor material of a first height that is variable, and an inactive portion comprising an oxide of the semiconductor material of a second variable height, complementary to the first height. Gate electrodes and source/drain terminals may be coupled through a transistor channel having any width that varies according to the first height. Oxidation of a semiconductor material may be selectively catalyzed to convert a desired portion of a non-planar body into the oxide of the semiconductor material. Oxidation may be enhanced through the application of a catalyst, such as one comprising metal and oxygen, for example.