A method for forming a multiplexor integrated circuit includes employing four complementary pairs of vertical field effect transistor (VFET) pairs, each of the complementary pairs of VFETs includes a first VFET device having a gate and a second VFET device having a gate, the gate of the first VFET device is connected to the gate of the second VFET device. The four complementary pairs VFET pairs are arranged to form a signal input portion of the multiplexor with four contact poly pitch (CPP) The plurality source/drain connections are operably connected.

Integrated chips and methods of forming the same include forming a gate stack around a first semiconductor fin and a second semiconductor fin. The gate stack around the second semiconductor fin is etched away. An extrinsic base is formed around the second semiconductor fin in a region exposed by etching away the gate stack.

A method is presented for forming a semiconductor structure. The method includes forming a plurality of fins over a source/drain region, forming a first spacer within troughs defined by the plurality of fins and depositing a high-k dielectric layer, a work function material layer, and a conducting layer. The method further includes etching the high-k dielectric layer, the work function material layer, and the conducting layer to form recesses between the plurality of fins, depositing a liner dielectric, and etching portions of the liner dielectric to form a plurality of second spacers having a U-shaped configuration. The method further includes forming an epitaxial layer over the plurality of fins such that a gap region is defined between the plurality of second spacers and the epitaxial layer.

A method is presented for forming a vertical field effect transistor (VFET) structure. The method includes forming a plurality of vertical fins over a substrate, forming a dummy gate between the plurality of vertical fins, removing the dummy gate with a subway etch to define a gate cavity, and forming a high-k metal gate (HKMG) stack within the gate cavity. The method further includes forming the first and second source/drain regions before the HKMG stack. The method further includes defining the HKMG stack by a replacement metal gate (RMG) process, the RMG process defined in part by the subway etch. The subway etch enables removal of the dummy gate from a side portion of the VFET structure.

Semiconductor devices having vertical FET (field effect transistor) devices with metallic source/drain regions are provided, as well as methods for fabricating such vertical FET devices. For example, a semiconductor device includes a first source/drain region formed on a semiconductor substrate, a vertical semiconductor fin formed on the first source/drain region, a second source/drain region formed on an upper surface of the vertical semiconductor fin, a gate structure formed on a sidewall surface of the vertical semiconductor fin, and an insulating material that encapsulates the vertical semiconductor fin and the gate structure. The first source/drain region comprises a metallic layer and at least a first epitaxial semiconductor layer. For example, the metallic layer of the first source/drain region comprises a metal-semiconductor alloy such as silicide.

Aspects of the disclosure include a semiconductor structure that includes a vertical fin structure having a top portion, a bottom portion, vertical side walls, a source area in contact with the vertical fin structure, a drain area in contact with the vertical fin structure, a plurality of spacers comprising a first oxide layer in contact with the source area, and a second oxide layer in contact with the drain area. The first oxide layer can have a thickness that is equal to a thickness of the second oxide layer.

A method for forming a hybrid semiconductor device includes growing a stack of layers on a semiconductor substrate. The stack of layers includes a bottom layer in contact with the substrate, a middle layer on the bottom layer and a top layer on the middle layer. First and second transistors are formed on the top layer. A protective dielectric is deposited over the first and second transistors. A trench is formed adjacent to the first transistors to expose the middle layer. The middle layer is removed from below the first transistors to form a cavity. A dielectric material is deposited in the cavity to provide a transistor on insulator structure for the first transistors and a bulk substrate structure for the second transistors.

Some embodiments include a transistor having a drain region and a source region. A conductive gate is between the source and drain regions. First channel material is between the gate and the source region. The first channel material is spaced from the gate by one or more insulative materials. Second channel material is between the first channel material and the source region, and directly contacts the source region. The first and second channel materials are transition metal chalcogenide. One of the source and drain regions is a hole reservoir region and the other is an electron reservoir region. Tunnel dielectric material may be between the first and second channel materials.

Techniques relate to a gate stack for a semiconductor device. A vertical fin is formed on a substrate. The vertical fin has an upper portion and a bottom portion. The upper portion of the vertical fin has a recessed portion on sides of the upper portion. A gate stack is formed in the recessed portion of the upper portion of the vertical fin.

A method of forming a vertical fin field effect transistor (vertical finFET) with an increased surface area between a source/drain contact and a doped region, including forming a doped region on a substrate, forming one or more interfacial features on the doped region, and forming a source/drain contact on at least a portion of the doped region, wherein the one or more interfacial features increases the surface area of the interface between the source/drain contact and the doped region compared to a flat source/drain contact-doped region interface.