Abstract: The subject disclosure relates to high mobility complementary metal-oxide-semiconductor (CMOS) devices and techniques for forming the CMOS devices with fins formed directly on the insulator. According to an embodiment, a method for forming such a high mobility CMOS device can comprise forming, via a first epitaxial growth of a first material, first pillars within first trenches formed within a dielectric layer, wherein the dielectric layer is formed on a silicon substrate, and wherein the first pillars comprise first portions with defects and second portions without the defects. The method can further comprise forming second trenches within a first region of the dielectric layer, and further forming second pillars within the second trenches via a second epitaxial growth of one or more second materials using the second portions of the first pillars as seeds for the second epitaxial growth.

Abstract: A method for manufacturing a semiconductor device includes forming a channel layer on a semiconductor substrate and forming at least two spacers on the channel layer. A first portion of a gate metal layer is formed between the spacers, and a dielectric layer is conformally deposited on the spacers and the first portion of the gate metal layer. In the method, part of the dielectric layer is directionally removed from surfaces which are parallel to an upper surface of the substrate. A second portion of the gate metal layer is formed between remaining portions of the dielectric layer and on the first portion of the gate metal layer, and a cap layer is deposited on the second portion of the gate metal layer. A lateral width the second portion of the gate metal layer is less than a lateral width of the first portion of the gate metal layer.

Abstract: Embodiments of the invention are directed to method of fabricating a semiconductor device. A non-limiting embodiment of the method includes performing fabrication operations to form a nanosheet field effect transistor (FET) device on a substrate, wherein the fabrication operations include forming gate spacers along a gate region of the nanosheet FET device, wherein each of the gate spacers comprises an upper segment and a lower segment.

Abstract: A method of forming a vertical fin field effect device is provided. The method includes, forming a vertical fin on a substrate, forming a masking block on the vertical fin, wherein the masking block extends a distance outward from the vertical fin sidewalls and endwalls, and a portion of the substrate surrounding the masking block is exposed. The method further includes removing at least a portion of the exposed portion of the substrate to form a recess and a fin mesa below the vertical fin, removing a portion of the fin mesa to form an undercut recess below an overhanging portion of the masking block, forming a spacer layer on the masking block and in the undercut recess, and removing a portion of the spacer layer to form an undercut spacer in the undercut recess.

Abstract: A method of controlling an effective gate length in a vertical field effect transistor is provided. The method includes forming a vertical fin on a substrate, and forming a bottom spacer layer on the substrate adjacent to the vertical fin. The method further includes forming a dummy gate block adjacent to the vertical fin on the bottom spacer layer. The method further includes forming a top spacer adjacent to the vertical fin on the dummy gate block, and removing the dummy gate block to expose a portion of the vertical fin between the top spacer and bottom spacer layer. The method further includes forming an absorption layer on the exposed portion of the vertical fin. The method further includes heat treating the absorption layer and vertical fin to form a dopant modified absorption layer, and removing the dopant modified absorption layer.

Abstract: High-mobility semiconductor fins are formed on an insulator layer using techniques allowing precise control of fin heights. Lattice-matched fins are grown epitaxially on sidewalls of an essentially defect-free portion of a semiconductor template. The fins are formed within laterally extending trenches in a top dielectric layer, the thickness of which determines fin height. The trenches extend orthogonally to the template. Epitaxial overgrowth above the top dielectric layer is removed by planarization. The fin template and top dielectric layer are removed, leaving sets of parallel fins on the insulator layer. The fin template can be replaced by an isolation region for electrically isolating sets of fins.

Abstract: A method of fabricating a vertical fin field effect transistor with a merged top source/drain, including, forming a source/drain layer at the surface of a substrate, forming a plurality of vertical fins on the source/drain layer; forming protective spacers on each of the plurality of vertical fins, forming a sacrificial plug between two protective spacers, forming a filler layer on the protective spacers not in contact with the sacrificial plug, and selectively removing the sacrificial plug to form an isolation region trench between the two protective spacers.

Abstract: A method of controlling an effective gate length in a vertical field effect transistor is provided. The method includes forming a vertical fin on a substrate, and forming a bottom spacer layer on the substrate adjacent to the vertical fin. The method further includes forming a dummy gate block adjacent to the vertical fin on the bottom spacer layer. The method further includes forming a top spacer adjacent to the vertical fin on the dummy gate block, and removing the dummy gate block to expose a portion of the vertical fin between the top spacer and bottom spacer layer. The method further includes forming an absorption layer on the exposed portion of the vertical fin. The method further includes heat treating the absorption layer and vertical fin to form a dopant modified absorption layer, and removing the dopant modified absorption layer.

Abstract: A method of forming a vertical fin field effect transistor (vertical finFET) with a self-aligned bottom source/drain, including forming a doped layer on a substrate, forming one or more vertical fins on the doped layer, forming a protective layer on the one or more vertical fins, wherein the protective layer has a thickness, and forming at least one isolation trench by removing at least a portion of the protective layer on the doped layer, wherein the isolation trench is laterally offset from at least one of the one or more vertical fins by the thickness of the protective layer.

Abstract: A beam shaping assembly for neutron capture therapy includes a beam inlet, a target having nuclear reaction with an incident proton beam from the beam inlet to produce neutrons forming a neutron beam, a moderator adjoining to the target, a reflector surrounding the moderator, a thermal neutron absorber adjoining to the moderator, a radiation shield arranged inside the beam shaping assembly and a beam outlet. The material of the moderator is subjected to a powder sintering process using a powder sintering device so as to change powders or a power compact into blocks. The reflector leads the neutrons deviated from the main axis back. The thermal neutron absorber is used for absorbing thermal neutrons so as to avoid overdosing in superficial normal tissue during therapy. The radiation shield is used for shielding leaking neutrons and photons so as to reduce dose of the normal tissue not exposed to irradiation.

Abstract: Techniques for controlling top spacer thickness in VFETs are provided. In one aspect, a method of forming a VFET device includes: depositing a dielectric hardmask layer and a fin hardmask(s) on a wafer; patterning the dielectric hardmask layer and the wafer to form a fin(s) and a dielectric cap on the fin(s); forming a bottom source/drain at a base of the fin(s); forming bottom spacers on the bottom source/drain; forming a gate stack alongside the fin(s); burying the fin(s) in a dielectric fill material; selectively removing the fin hardmask(s); recessing the gate stack to form a cavity in the dielectric fill material; depositing a spacer material into the cavity; recessing the spacer material to form top spacers; removing the dielectric cap; and forming a top source/drain at a top of the fin(s). A VFET device is also provided.

Abstract: A method of fabricating adjacent vertical fins with top source/drains having an air spacer and a self-aligned top junction, including, forming two or more vertical fins on a bottom source/drain, forming a top source/drain on each of the two or more vertical fins, wherein the top source/drains are formed to a size that leaves a gap between the adjacent vertical fins, and forming a source/drain liner on the top source/drains, where the source/drain liner occludes the gap between adjacent top source/drains to form a void space between adjacent vertical fins.

Abstract: A technique relates to a semiconductor device. A first vertical fin is formed with a first gate stack and a second vertical fin with a second gate stack. The second vertical fin has a hardmask on top. The first vertical fin is adjacent to a first bottom source or drain (S/D) region and the second vertical fin is adjacent to a second bottom S/D region. The first gate stack is reduced to a first gate length and the second gate stack to a second gate length, the second gate length being greater than the first gate length because of the hardmask. The hardmask is removed. A first top S/D region is adjacent to the first vertical fin and a second top S/D region is adjacent to the second vertical fin.

Abstract: A method for manufacturing a semiconductor device includes forming a channel layer on a semiconductor substrate and forming at least two spacers on the channel layer. A first portion of a gate metal layer is formed between the spacers, and a dielectric layer is conformally deposited on the spacers and the first portion of the gate metal layer. In the method, part of the dielectric layer is directionally removed from surfaces which are parallel to an upper surface of the substrate. A second portion of the gate metal layer is formed between remaining portions of the dielectric layer and on the first portion of the gate metal layer, and a cap layer is deposited on the second portion of the gate metal layer. A lateral width the second portion of the gate metal layer is less than a lateral width of the first portion of the gate metal layer.

Abstract: A method of forming fin field effect devices is provided. The method includes forming a plurality of vertical fins on a substrate. The method further includes forming a dielectric pillar on the substrate between two adjacent vertical fins, wherein at least one of the vertical fins is on a first region of the substrate, and at least one of the vertical fins is on a second region of the substrate. The method further includes growing a bottom source/drain layer on the first region of the substrate and the second region of the substrate. The method further includes depositing a bottom spacer layer on the bottom source/drain layer, and a filler layer on the bottom spacer layer. The method further includes forming a cover block on the first region of the substrate, and removing the portion of the filler layer on the second region of the substrate.

Abstract: Embodiments are directed to a method of fabricating a semiconductor device. A non-limiting example of the method includes performing fabrication operations to form a nanosheet field effect transistor device on a substrate. The fabrication operations include, forming a channel stack over the substrate, wherein the channel stack include stacked and spaced apart channel nanosheets. A metal gate is formed adjacent to end regions of the channel stack and around and between the stacked and spaced apart channel nanosheets. A permanent dummy gate is formed above the channel stack.

Abstract: A technique relates to a semiconductor device. A stack is formed of alternating layers of inserted layers and channel layers on a substrate. Source or drain (S/D) regions are formed on opposite sides of the stack. The inserted layers are converted into oxide layers. Gate materials are formed on the stack.

Abstract: A semiconductor device is described. The semiconductor device includes a nanosheet stack including a sacrificial nanosheet oriented substantially parallelly to a substrate and a channel nanosheet disposed on the sacrificial nanosheet. The semiconductor device includes a gate formed in a direction orthogonal to the plane of the nanosheet stack, with a gate spacer positioned along a sidewall of the gate. The semiconductor device includes an inner spacer liner deposited around the nanosheet stack and the gate spacer. A first etching of the inner spacer liner is configured to produce an outer profile of the inner spacer liner, the outer profile having a substantially flat side section relative to an edge of the channel nanosheet. A second etching of the inner spacer liner is configured to remove substantially all material of the inner spacer liner from the edge of the channel nanosheet.

Abstract: A method of forming fin field effect devices is provided. The method includes forming a plurality of vertical fins on a substrate. The method further includes forming a dielectric pillar on the substrate between two adjacent vertical fins, wherein at least one of the vertical fins is on a first region of the substrate, and at least one of the vertical fins is on a second region of the substrate. The method further includes growing a bottom source/drain layer on the first region of the substrate and the second region of the substrate. The method further includes depositing a bottom spacer layer on the bottom source/drain layer, and a filler layer on the bottom spacer layer. The method further includes forming a cover block on the first region of the substrate, and removing the portion of the filler layer on the second region of the substrate.

Abstract: A method for manufacturing a semiconductor device includes forming a fin on a semiconductor substrate. In the method, a bottom source/drain region is formed between the fin and the semiconductor substrate, and a top source/drain region is formed on the fin. The method further includes forming a cap layer covering part of a top surface of the top source/drain region. A portion of the top source/drain region and an underlying portion of the fin not covered by the cap layer are removed. The removal exposes a portion of the bottom source/drain region. A dielectric spacer is formed on a side of the fin adjacent the exposed portion of the bottom source/drain region, and extends onto a side of the top source/drain region. A bottom source/drain contact is formed on the exposed portion of the bottom source/drain region and on the dielectric spacer.