Abstract: Parasitic transistor formation under a semiconductor containing nanosheet device is eliminated by forming an airgap between the source/drain regions of the semiconductor containing nanosheet device and the semiconductor substrate. The airgap is created by forming a sacrificial germanium-containing semiconductor material at the bottom of the source/drain regions prior to the epitaxial growth of the source/drain regions from physically exposed sidewalls of each semiconductor channel material nanosheet of a nanosheet material stack. After inner dielectric spacer formation, the sacrificial germanium-containing semiconductor material can be reflown to seal any possible openings to the semiconductor substrate. The source/drain regions are then epitaxially grown and thereafter, the sacrificial germanium-containing semiconductor material is removed from the structure creating the airgap between the source/drain regions of the semiconductor containing nanosheet device and the semiconductor substrate.

Abstract: Vertical transport field effect transistors (FETs) having improved device performance are provided. Notably, vertical transport FETs having a gradient threshold voltage are provided. The gradient threshold voltage is provided by introducing a threshold voltage modifying dopant into a physically exposed portion of a metal gate layer composed of an n-type workfunction TiN. The threshold voltage modifying dopant changes the threshold voltage of the original metal gate layer.

Abstract: Provided is a nanosheet semiconductor device. In embodiments of the invention, the nanosheet semiconductor device includes a channel nanosheet formed over a substrate. The nanosheet semiconductor device includes a buffer layer formed between the substrate and the channel nanosheet. The buffer layer has a lower conductivity than the channel nanosheet.

Abstract: A FinFET having an asymmetric threshold voltage distribution is provided by forming a halo ion implantation region in a semiconductor fin, and in close proximity to a source region, of the FinFET. The halo ion implantation region is self-aligned to an outermost sidewall surface of the functional gate structure of the FinFET and it has a higher dopant concentration than the remaining portion of the channel region.

Abstract: A cross-point memory is provided that enables the use of complementary pass transistors as selection devices in a dense memory array. The density impact of doubling the transistor count and the additional lines required for addressing the array is minimized by stacking the memory elements on vertical transistors with shared transistor bodies (i.e., semiconductor material pillars) and shared wordlines.

Abstract: A method is presented for reducing external resistance of a vertical field-effect-transistor (FET). The method includes forming a plurality of fins over a sacrificial layer disposed over a substrate, selectively removing the sacrificial layer to form an etch stop layer in direct contact with the substrate, disposing embedded bottom source/drain regions between a bottom portion of the plurality of fins and the etch stop layer, disposing encapsulation layers over the plurality of fins, recessing at least one of the encapsulation layers to expose top portions of the plurality of fins, forming top spacers adjacent the top portions of the plurality of fins, and forming top source/drain regions over the top portions of the plurality of fins.

Abstract: Semiconductor devices and methods of forming the same include forming an inner spacer on a semiconductor fin. Two outer spacers are formed around the inner spacer, with one outer spacer being in contact with the inner spacer and with the other outer spacer being separated from the inner spacer by a gap. A dipole-forming layer is formed on the semiconductor fin in the gap. The inner spacer is etched away. A gate stack is formed on the semiconductor fin, between the outer spacers.

Abstract: A method for forming a nanosheet semiconductor device includes forming a nanosheet stack comprising channel nanosheets. The method includes depositing silicon on the nanosheet stack, the silicon completely filling a space between adjacent channel nanosheets. The method includes etching the silicon. The method includes exposing the nanosheet stack to a gas phase heat treatment.

Abstract: A method of forming a source/drain contact is provided. The method includes forming a sacrificial layer on a source/drain, and depositing an oxidation layer on the sacrificial layer. The method further includes heat treating the oxidation layer and the sacrificial layer to form a modified sacrificial layer. The method further includes forming a protective liner on the modified sacrificial layer, and depositing an interlayer dielectric layer on the protective liner. The method further includes forming a trench in the interlayer dielectric layer that exposes a portion of the protective liner.

Abstract: A method of forming a source/drain contact is provided. The method includes forming a sacrificial layer on a source/drain, and depositing an oxidation layer on the sacrificial layer. The method further includes heat treating the oxidation layer and the sacrificial layer to form a modified sacrificial layer. The method further includes forming a protective liner on the modified sacrificial layer, and depositing an interlayer dielectric layer on the protective liner. The method further includes forming a trench in the interlayer dielectric layer that exposes a portion of the protective liner.

Abstract: A semiconductor structure containing a gate-all-around nanosheet field effect transistor having a self-limited inner spacer composed of a rare earth doped germanium dioxide that provides source/drain isolation between rare earth metal silicide ohmic contacts is provided.

Abstract: An I/O device nanosheet material stack of suspended semiconductor channel material nanosheets is provided above a semiconductor substrate. A physically exposed portion of each suspended semiconductor channel material nanosheet is thinned to increase the inter-nanosheet spacing between each vertically stacked semiconductor channel material nanosheet. An I/O device functional gate structure is formed wrapping around the thinned portion of each suspended semiconductor channel material nanosheet.

Abstract: A self-limiting etch is used to provide a semiconductor base located between a semiconductor substrate and a semiconductor fin. The semiconductor base has an upper portion, a lower portion and a midsection. The midsection has a narrower width than the lower and upper portions. A bottom source/drain structure is grown from surfaces of the semiconductor substrate and the semiconductor base. The bottom source/drain structure has a tip region that contacts the midsection of the semiconductor base. The bottom source/drain structures on each side of the semiconductor fin are in close proximity to each other and they have increased volume. Reduced access resistance may also be achieved since the bottom source/drain structure has increased volume.

Abstract: A semiconductor structure including vertically stacked n-type field effect transistors (nFETs) and p-type field effect transistors (pFETs) containing suspended semiconductor channel material nanosheets having an isolation layer located between a pFET source/drain (S/D) structure and an nFET S/D region is provided together with a method of forming such a structure. The pFET S/D structure includes a pFET S/D SiGe region having a first germanium content and an overlying SiGe region having a second germanium content that is greater than the first germanium content.

Abstract: A resistive memory structure is provided. The resistive memory structure includes a vertical fin on a substrate, wherein the sidewalls of the vertical fin each have a {100} crystal face. The resistive memory structure further includes a fin template on the vertical fin, and a gate structure on the vertical fin. The resistive memory structure further includes a top source/drain on opposite sidewalls of the vertical fin, and a bottom electrode layer on the top source/drain, wherein the bottom electrode layer is on opposite sides of the fin template. The resistive memory structure further includes a first middle resistive layer on a portion of the bottom electrode layer, a top electrode layer on the first middle resistive layer, and a first electrical contact on a portion of the bottom electrode layer.

Abstract: A method for fabricating stacked resistive memory with individual switch control is provided. The method includes forming a first random access memory (ReRAM) device. The method further includes forming a second ReRAM device in a stacked nanosheet configuration on the first ReRAM device. The method also includes forming separate gate contacts for the first ReRAM device and the second ReRAM device.

Abstract: An FET comprises a source, a drain, a channel, and a gate encompassing the channel. The channel has a first region that is thinner than in a second region. The Threshold Voltage, Vth, is larger in the first region than in the second region causing an asymmetric Vth across the length of the channel. Modeling has shown that the Vth increases along the channel from about 50 milliVolts (mV) for N-FETs (about 55 mV for a P-FETs) to about 125 mV for N-FETs (about 180 mV for P-FETs) as the channel width decreases from 4 nanometers (nm) to 2 nm.

Abstract: A p-type FinFET has an oxygen reservoir disposed on the gate stack. The oxygen reservoir provides an oxygen rich environment during processing steps of manufacturing the device to help the work function metal retain or obtain oxygen to maintain or increase the work function and keep the Vth of the device lower.

Abstract: A method of forming a complementary metal oxide semiconductor (CMOS) device is provided. The method includes forming a separate gate structure on each of a pair of vertical fins, wherein the gate structures include a gate dielectric layer and a gate metal layer, and forming a protective liner layer on the gate structures. The method further includes heat treating the pair of gate structures, and replacing the protective liner layer with an encapsulation layer. The method further includes exposing a portion of the gate dielectric layer by recessing the encapsulation layer. The method further includes forming a top source/drain on the top surface of one of the pair of vertical fins, and subjecting the exposed portion of the gate dielectric layer to a second heat treatment conducted in an oxidizing atmosphere.

Abstract: Semiconductor devices and methods of forming the same include partially etching sacrificial layers in a first stack of alternating sacrificial layers and channel layers to form first recesses. A first inner spacer sub-layer is formed in the first recesses from a first dielectric material. A second inner spacer sub-layer is formed in the first recesses from a second dielectric material, different from the first dielectric material. The sacrificial layers are etched away. The first inner spacer sub-layer is etched away. A gate stack is formed on and around the channel layers and in contact with the second inner spacer sub-layer.