Abstract: Techniques for optimizing junctions of a gate-all-around nanosheet device are provided. In one aspect, a method of forming a nanosheet device includes: forming an alternating series of first/second nanosheets including a first/second material as a stack on a wafer; forming a dummy gate(s) on the stack; patterning the stack into a fin stack(s) beneath the dummy gate(s); etching the fin stack(s) to selectively pull back the second nanosheets in the fin stack(s) forming pockets in the fin stack(s); filling the pockets with a strain-inducing material; burying the dummy gate(s) in a dielectric material; selectively removing the dummy gate(s) forming a gate trench(es) in the dielectric material; selectively removing either the first nanosheets or the second nanosheets from the fin stack(s); and forming a replacement gate(s) in the gate trench(es). A nanosheet device is also provided.

Abstract: A method for making a semiconductor device, including: a) etching a stack of a layer of a second semiconductor, which is crystalline, arranged between a substrate and a layer of a first semiconductor, which is crystalline, the second semiconductor being different from the first semiconductor and subjected to a compressive stress, forming a nanowire stack, b) making a dummy gate and outer spacers, covering a part of the nanowire stack which is formed by portions of the nanowires, c) etching the nanowire stack such that only said part of the stack is preserved, d) removing the portion of the second semiconductor nanowire, e) depositing, in a space formed by this removal, a sacrificial material portion, f) making source and drain regions and inner spacers, g) removing the dummy gate and the sacrificial material portion, h) making a gate.

Abstract: The method of manufacturing at least one field effect transistor is such that it comprises a step of supplying a substrate (1) surmounted by first, second and third structures (100, 200, 300), the second structure (200) being arranged between the first and third structures (100, 300). The second structure (200) comprises at least one first nano-object (201) located away from the substrate (1), a part (201c) of the first nano-object (201) being intended to form a channel area of the transistor.

Abstract: FET transistor (100) comprising: a semiconductor portion (104) of which a first part (106) forms a channel; a gate (108) at least partly surrounding the first part; internal dielectric spacers (112) arranged around doped second parts (114) of the semiconductor portion between which the first part is arranged and which form extension regions; electrically conductive portions (120) in contact with doped surfaces of extremities (118) of the semiconductor portion and with doped surfaces of third parts (116) of the semiconductor portion, forming part of the source and drain regions, at least partly surrounding the third parts, with each of the second parts being arranged between the first part and one of the third parts.

Abstract: A method of fabrication of a semiconductor device including the implementation of the following steps: fabrication of a stack including at least one first portion of a first semiconductor and at least one second portion of a second semiconductor which is different from the first semiconductor, such that the thickness of at least the first portion is substantially equal to the thickness of at least one nanostructure intended to be made; and thermal treatment of the stack at a temperature which causes surface migration of atoms of the second semiconductor of the second portion towards at least one part of the first portion which exhibits at least one free surface and at which the nanostructure containing at least atoms of the second semiconductor is formed.

Abstract: The method for fabricating a field-effect transistor comprises a step of producing a sacrificial gate and first and second spacers covering first, second and third parts of successive first to fifth semiconductor nanowires of a stack. The fabricating method comprises a step of forming a channel area of the transistor, which channel area is compressively stressed and distinct from the second part of the third nanowire. The channel area is connected to a source electrode of the transistor by the first part of the second nanowire, and to a drain electrode of the transistor by the third part of the second nanowire.

Abstract: Method for producing a semiconductor device, comprising: producing a stack including a first crystalline semiconductor portion intended to form a channel and arranged on at least one second portion which can be selectively etched vis-à-vis the first portion, producing a dummy gate and external spacers, etching the stack, a remaining part of the stack under the dummy gate and the external spacers being conserved, producing source/drain by epitaxy from the remaining part of the stack; removing the dummy gate and the second portion, oxidizing portions of the source/drain from the parts of the source/drain revealed by the removal of the second portion, forming internal spacers, producing a gate electrically insulated from the source/drain by the external and internal spacers.

Abstract: Method for fabricating at least one FET transistor (100a, 100b) comprising: fabrication of at least one first semiconducting portion (114) that will form a channel of the FET transistor, fabrication of second semiconducting portions (122, 124, 126) that will be used to form source and drain regions, such that the first semiconducting portion is located between first ends of the second semiconducting portions and such that second ends of the second semiconducting portions opposite the first ends, are in contact with bearing surfaces, and comprising at least one semiconducting material for which the crystalline structure or the atomic organisation, can be modified when a heat treatment is applied to it; heat treatment generating a modification to the crystalline structure of the semiconducting material of the second semiconducting portions and creating a strain (128) in the first semiconducting portion.

Abstract: A process for fabricating a gate-wrap-around field-effect transistor is provided, including providing a substrate surmounted with first and second nanowires extending in a same longitudinal direction and having a median portion covered by a first material, and first and second ends that are arranged on either side of the median portion, a periphery of which is covered by respective first and second dielectric spacers made of a second material that is different from the first material, the ends having exposed lateral faces; doping a portion of the first and second ends via the lateral faces; depositing an amorphous silicon alloy on the first and second lateral faces followed by crystallizing the alloy; and depositing a metal on either side of the nanowires to form first and second metal contacts that respectively make electrical contact with the doped portions of the first and second ends of the nanowires.

Abstract: A method for making a semiconductor device, including: a) making, on a substrate, a stack comprising a first semiconductor portion able to form an active zone and arranged between two second portions of a material able to be selectively etched relative to the semiconductor of the first portion, b) making, on a part of the stack, outer spacers and a dummy gate, c) etching the second portions such that remaining parts are arranged under the dummy gate, d) partially oxidizing the remaining parts from the outer faces, forming inner spacers, e) removing the dummy gate and non-oxidized parts of the remaining parts arranged under the dummy gate, f) making a gate between the outer spacers and between the inner spacers and covering the channel.

Abstract: Method for making a semiconductor device, comprising: a) making of a stack of crystalline semiconductor layers comprising a first layer and a second layer capable of being selectively etched in relation to the first layer, b) etching of part of the stack, a portion of the first layer forms a nanowire (132) arranged on the second layer, c) selective etching of second layer, d) making, beneath the nanowire, of a sacrificial portion which has an etching selectivity which is greater than that of the second layer, e) making of a sacrificial gate and of an external spacer surrounding the sacrificial gate, f) etching of the stack, revealing ends of the nanowire and of the sacrificial portion aligned with the external spacer, g) selective etching of parts of the sacrificial portion, from its ends, forming aligned cavities beneath the external spacer, h) making of an internal spacer within the cavities.

Abstract: Fabrication of a microelectronic device comprising a semiconductor structure provided with semiconductor bars positioned above one another, the method comprising the following steps: creating, on a substrate, a stacked structure comprising an alternation of first bars containing a first material and having a first critical dimension and second bars (142, 144, 146) containing a second material, the second material being a semiconductor, the second bars having a second critical dimension greater than the first critical dimension, then, surface doping protruding lateral portions (15) of the second bars before formation of a source and drain block on these portions.

Abstract: A process for fabricating a gate-wrap-around field-effect transistor is provided, including: providing a superposition of first to third nanowires, each made of a semiconductor, the second nanowire being subjected to a strain along its longitudinal axis, a median portion of the first to third nanowires being covered by a sacrificial gate; forming voids by removing a portion of the first and third nanowires that is intermediate between their ends and their median portion, while preserving the superposition of the first to third nanowires level with the ends and under the sacrificial gate; forming an electrical insulator in the voids around the second nanowire; removing the sacrificial gate and the median portion of the first and third nanowires; and forming a gate electrode wrapped around the median portion of the second nanowire.

Abstract: Method of manufacturing a structure with semiconducting bars suitable for forming one at least one transistor channel, including the following steps: a) make a semiconducting structure, composed of an alternation of first bars based on a first material and second bars based on a second material, the second material being a semiconducting material, then b) remove exposed portions of the structure based on the first material through an opening in a mask formed on the structure, the removal being made by selective etching in the opening of the first material relative to the second material, so as to expose a space around the second bars, then c) grow a given semiconducting material (25) around the second bars (6c) in the opening, the given semiconducting material having a mesh parameter different from the mesh parameter of the second material (7) so as to induce a strain on the sheaths based on the given semiconducting material.

Abstract: The invention relates to a process for fabricating a vertical transistor, comprising the step of providing a substrate surmounted by a stack of first, second and third layers made of first, second and third semiconductors, respectively, said second semiconductor being different from the first and third semiconductors. The process further includes horizontally growing first, second and third dielectric layers, by oxidation, from the first, second and third semiconductor layers, respectively, with a second dielectric layer, the thickness of which differs from the thickness of said first and third dielectric layers and removing the second dielectric layer so as to form a recess that is vertically self-aligned with the second semiconductor layer, which recess is positioned vertically between first and second blocks that are made facing the first and third semiconductor layers. Finally, the process includes forming a gate stack in said self-aligned recess.

Abstract: A process for fabricating a gate-wrap-around field-effect transistor is provided, including: providing a superposition of first to third nanowires, each made of a semiconductor, the second nanowire being subjected to a strain along its longitudinal axis, a median portion of the first to third nanowires being covered by a sacrificial gate; forming voids by removing a portion of the first and third nanowires that is intermediate between their ends and their median portion, while preserving the superposition of the first to third nanowires level with the ends and under the sacrificial gate; forming an electrical insulator in the voids around the second nanowire; removing the sacrificial gate and the median portion of the first and third nanowires; and forming a gate electrode wrapped around the median portion of the second nanowire.

Abstract: A process for fabricating a gate-wrap-around field-effect transistor is provided, including providing a substrate surmounted with first and second nanowires extending in a same longitudinal direction and having a median portion covered by a first material, and first and second ends that are arranged on either side of the median portion, a periphery of which is covered by respective first and second dielectric spacers made of a second material that is different from the first material, the ends having exposed lateral faces; doping a portion of the first and second ends via the lateral faces; depositing an amorphous silicon alloy on the first and second lateral faces followed by crystallizing the alloy; and depositing a metal on either side of the nanowires to form first and second metal contacts that respectively make electrical contact with the doped portions of the first and second ends of the nanowires.

Abstract: A process for fabricating a vertical transistor is provided, including steps of providing a substrate surmounted by a stack of first to third layers made of first to third semiconductors materials of two different types; partially etching the first and third layers with an etching that is selective, so as to form a first void in the first layer and a third void in the third layer, extending to the lower surface and to the upper surface of the second layer, respectively; filling the voids in order to form spacers making contact with the lower surface and the upper surface, respectively; partially etching the second layer with an etching that is selective, so as to form a second void between the first and second spacers; and depositing a conductor material in the second void.

Abstract: The invention relates to a process for fabricating a vertical transistor, comprising the step of providing a substrate surmounted by a stack of first, second and third layers made of first, second and third semiconductors, respectively, said second semiconductor being different from the first and third semiconductors. The process further includes horizontally growing first, second and third dielectric layers, by oxidation, from the first, second and third semiconductor layers, respectively, with a second dielectric layer, the thickness of which differs from the thickness of said first and third dielectric layers and removing the second dielectric layer so as to form a recess that is vertically self-aligned with the second semiconductor layer, which recess is positioned vertically between first and second blocks that are made facing the first and third semiconductor layers. Finally, the process includes forming a gate stack in said self-aligned recess.

Abstract: A process for fabricating a gate-wrap-around field-effect transistor is provided, including: providing a superposition of first to third nanowires, each made of a semiconductor, the second nanowire being subjected to a strain along its longitudinal axis, a median portion of the first to third nanowires being covered by a sacrificial gate; forming voids by removing a portion of the first and third nanowires that is intermediate between their ends and their median portion, while preserving the superposition of the first to third nanowires level with the ends and under the sacrificial gate; forming an electrical insulator in the voids around the second nanowire; removing the sacrificial gate and the median portion of the first and third nanowires; and forming a gate electrode wrapped around the median portion of the second nanowire.