After forming a buried nanowire segment surrounded by a gate structure located on a substrate, an epitaxial source region is grown on a first end of the buried nanowire segment while covering a second end of the buried nanowire segment and the gate structure followed by growing an epitaxial drain region on the second end of the buried nanowire segment while covering the epitaxial source region and the gate structure. The epitaxial source region includes a first semiconductor material and dopants of a first conductivity type, while the epitaxial drain region includes a first semiconductor material different from the first semiconductor material and dopants of a second conductivity type opposite the first conductivity type.

A semiconductor device includes a substrate including a first region, and a second region, a first gate structure and a second gate structure on the substrate of the first region, a third gate structure and a fourth gate structure on the substrate of the second region, a first interlayer insulating film on the substrate of the first region and including a first lower interlayer insulating film and a first upper interlayer insulating film, a second interlayer insulating film on the substrate of the second region and including a second lower interlayer insulating film and a second upper interlayer insulating film, a first contact between the first gate structure and the second gate structure and within the first interlayer insulating film, and a second contact formed between the third gate structure and the fourth gate structure and within the second interlayer insulating film.

A vertical tunneling FET (TFET) provides low-power, high-speed switching performance for transistors having critical dimensions below 7 nm. The vertical TFET uses a gate-all-around (GAA) device architecture having a cylindrical structure that extends above the surface of a doped well formed in a silicon substrate. The cylindrical structure includes a lower drain region, a channel, and an upper source region, which are grown epitaxially from the doped well. The channel is made of intrinsic silicon, while the source and drain regions are doped in-situ. An annular gate surrounds the channel, capacitively controlling current flow through the channel from all sides. The source is electrically accessible via a front side contact, while the drain is accessed via a backside contact that provides low contact resistance and also serves as a heat sink. Reliability of vertical TFET integrated circuits is enhanced by coupling the vertical TFETs to electrostatic discharge (ESD) diodes.

The invention includes a semiconductor device comprising an interlevel dielectric layer over a buried insulator layer over a semiconductor substrate; a source and drain in the interlevel layer; a channel between the source and drain, the channel including a first region having a first bandgap adjacent to a second region having a second bandgap, wherein the first band gap is larger than the second bandgap; and a gate over the channel.

The invention includes a semiconductor device comprising an interlevel dielectric layer over a buried insulator layer over a semiconductor substrate; a source and drain in the interlevel layer; a channel between the source and drain, the channel including a first region having a first bandgap adjacent to a second region having a second bandgap, wherein the first band gap is larger than the second bandgap; and a gate over the channel.

Tunneling field effect transistors (TFETs) for CMOS architectures and approaches to fabricating N-type and P-type TFETs are described. For example, a tunneling field effect transistor (TFET) includes a homojunction active region disposed above a substrate. The homojunction active region includes a relaxed Ge or GeSn body having an undoped channel region therein. The homojunction active region also includes doped source and drain regions disposed in the relaxed Ge or GeSn body, on either side of the channel region. The TFET also includes a gate stack disposed on the channel region, between the source and drain regions. The gate stack includes a gate dielectric portion and gate electrode portion.

Inverters and methods of manufacture thereof are disclosed. In some embodiments, an inverter includes a substrate and a first tunnel FET (TFET) disposed over the substrate. The first TFET is a first fin field effect transistor (FinFET). A second TFET is over the first TFET. The second TFET is a second FinFET. A junction isolation region is disposed between a source of the first TFET and a source of the second TFET.

Among other things, one or more techniques for forming a vertical tunnel field effect transistor (FET), and a resulting vertical tunnel FET are provided herein. In an embodiment, the vertical tunnel FET is formed by forming a core over a first type substrate region, forming a second type channel shell around a circumference greater than a core circumference, forming a gate dielectric around a circumference greater than the core circumference, forming a gate electrode around a circumference greater than the core circumference, and forming a second type region over a portion of the second type channel shell, where the second type has a doping opposite a doping of the first type. In this manner, line tunneling is enabled, thus providing enhanced tunneling efficiency for a vertical tunnel FET.

A field effect transistor (FET) includes a nanosheet stack having first and second stacked semiconductor channel layers. The first channel layer defines a channel region of a tunnel FET, and the second channel layer defines a channel region of a thermionic FET. Source and drain regions are provided on opposite sides of the nanosheet stack such that the first and second channel layers extend therebetween. A first portion of the source region adjacent the first channel layer and a second portion of the source region adjacent the second channel layer have opposite semiconductor conductivity types. Related fabrication and operating methods are also discussed.

A semiconductor device includes an electrostatic discharge (ESD) device formed adjacent to a first fin field effect transistor (finFET). The device includes a substrate, the first finFET and the ESD device. The first finFET is formed such that it includes finFET fins extending from the substrate. The ESD device includes two vertically stacked PN diodes including vertically stacked first, second, third and fourth layers. The first layer is an N doped layer and is disposed directly over the substrate, the second layer is a P doped layer and is disposed directly over the first layer, the third layer is an N doped layer and is disposed directly over the second layer and the fourth layer is a P doped layer and is disposed directly over the third layer.