Abstract: One example includes a semiconductor device. The semiconductor device include a carbon nanotube substrate, a self-assembled monolayer, and a gate oxide. The self-assembled monolayer overlies the carbon nanotube substrate and is comprised of molecules each including a tail group, a carbon backbone, and a head group. The gate oxide overlies the self-assembled monolayer, wherein the self-assembled monolayer forms an interface between the carbon nanotube substrate and the gate oxide.

Abstract: A method for fabricating a nanowire transistor is disclosed. First, a substrate is provided, and a stack structure is formed on the substrate, in which the stack structure includes a first semiconductor layer and a second semiconductor layer and the first semiconductor layer and the second semiconductor layer are made of different material. Next, a hard mask is formed on the stack structure and a first spacer adjacent to the hard mask, part of the stack structure is removed; a second spacer is formed adjacent to the first spacer and the stack structure; and a source/drain structure is formed adjacent to two sides of the second spacer.

Abstract: A method for manufacturing a semiconductor device includes forming a doped silicon layer on a bulk substrate, forming an undoped silicon cap layer on the doped silicon layer, forming a stacked configuration of silicon germanium (SiGe) and silicon layers on the undoped silicon cap layer, wherein the stacked configuration comprises a repeating arrangement of a silicon layer stacked on an SiGe layer, forming a plurality of dummy gates spaced apart from each other on the stacked configuration, the doped silicon layer and the undoped silicon cap layer, forming a spacer layer on each of the plurality of dummy gates, and on the doped silicon layer and the undoped silicon cap layer, selectively etching the doped silicon layer with respect to the undoped silicon layer, and filling the area from where the doped s silicon layer was selectively removed with a dielectric layer.

Abstract: A MOS transistor with stacked nanowires and a method of manufacturing the same. The transistor may include a stack of cascaded nanowires extending in a first direction on a substrate; a gate stack extending in a second direction across the nanowire stack; source and drain regions disposed on opposite sides of the gate stack in the second direction; and a channel region constituted of the nanowire stack between the source and drain regions. The cascaded nanowires can be formed by repeated operations of etching back, and lateral etching and then filling of grooves, thereby increasing an effective width of the channel, increasing a total area of an effective conductive section, and thus improving a drive current.

Abstract: A device includes a substrate, a first nanowire field effect transistor (FET), and a second nanowire FET positioned between the substrate and the first nanowire FET. The device also includes a first nanowire electrically coupled to the first nanowire FET and to the second nanowire FET.

Abstract: A nanowire device and a method of making a nanowire device are provided. The device includes a plurality of nanowires functionalized with different functionalizing compounds. The method includes functionalizing the nanowires with a functionalizing compound, dispersing the nanowires in a polar or semi-polar solvent, aligning the nanowires on a substrate such that longitudinal axes of the nanowires are oriented about perpendicular to a major surface of the substrate, and fixing the nanowires to the substrate.

Abstract: A semiconductor device including a gate structure present on at least two suspended channel structures, and a composite spacer present on sidewalls of the gate structure. The composite spacer may include a cladding spacer present along a cap portion of the gate structure, and an inner spacer along the channel portion of the gate structure between adjacent channel semiconductor layers of the suspended channel structures. The inner spacer may include a crescent shape with a substantially central seam.

Abstract: A method includes forming a first semiconductor stack using an epitaxial growth process, the first semiconductor stack comprising a first plurality of semiconductor layers alternating with a second plurality of semiconductor layers, the first plurality of semiconductor layers comprising a first semiconductor material and the second plurality of semiconductor layers comprising a second semiconductor material that is different than the first semiconductor material. The method further includes patterning the first semiconductor stack to form a set of semiconductor stack features, forming isolation features between the semiconductor stack features, removing at least one of the semiconductor stack features, thereby forming at least one trench, and forming, within the trench, a second semiconductor stack using an epitaxial growth process, the second semiconductor stack having different characteristics than the first semiconductor stack.

Abstract: Multi-Vt horizontal nanosheet devices and a method of making the same. In one embodiment, an integrated circuit includes a plurality of horizontal nanosheet devices (hNS devices) on a top surface of a substrate, the plurality of hNS devices including a first hNS device and a second hNS device spaced apart from each other horizontally. Each of the hNS devices includes a first and a second horizontal nanosheets spaced apart vertically; and a gate stack between the first and second horizontal nanosheets, the gate stack including a work function metal (WFM) layer. A thickness of the first and second horizontal nanosheets of the first hNS device is different from a thickness of the first and second horizontal nanosheets of the second hNS device, and a thickness of the WFM layer of the first hNS device is different from a thickness of the WFM layer of the second hNS device.

Abstract: A semiconductor may include a semiconductor substrate including a first region and a second region disposed at opposite sides of the first region, a first trench formed in the first region, a buffer layer filling a portion of the first trench, a first semiconductor layer formed on the buffer layer, a second semiconductor layer forming a hetero-junction with the first semiconductor layer on the first semiconductor layer of the first region and a gate electrode formed on the second semiconductor layer of the first region.

Abstract: An integrated circuit device may include a substrate including a main surface, a compound semiconductor nanowire extending from the main surface in a first direction perpendicular to the main surface and including a first section and a second section alternately arranged in the first direction, a gate electrode covering the first section, and a gate dielectric layer between the first section and the gate electrode. The first section and the second section may have the same composition as each other and may have different crystal phases from each other.

Abstract: A compound semiconductor device includes: a semiconductor substrate; a channel layer over the semiconductor substrate; a carrier supply layer over the channel layer; and a gate electrode, a source electrode and a drain electrode above the carrier supply layer. The semiconductor substrate includes an impurity-containing region containing an impurity, the impurity forms a level lower than a lower edge of a conduction band of silicon by 0.25 eV or more, the impurity forms the level higher than an upper edge of a valence band of silicon.

Abstract: The disclosed technology generally relates to a semiconductor device, and more particularly to a gate all around (GAA) semiconductor device and a method for fabricating the same. In one aspect, a semiconductor device has a vertical stack of nanowires formed on a substrate, wherein the vertical stack of nanowires comprises an n-type nanowire and a p-type nanowire each extending in a longitudinal direction parallel to a main surface of the substrate. The n-type nanowire comprises a first material and the p-type nanowire comprises an inner part having two sides and an outer part at each side of the inner part in the longitudinal direction, wherein one or both of the two outer parts comprises a second material different from the first material. The n-type nanowire and the p-type nanowire each comprises a channel region electrically coupled to respective source and drain regions. The channel region of the p-type nanowire comprises the inner part.

Abstract: After forming a gate stack straddling a portion of each semiconductor fin of a plurality of semiconductor fins located over a substrate, a gate liner is formed on sidewalls of a lower portion of the gate stack that contacts the plurality of semiconductor fins and a gate spacer having a width greater than a width of the gate liner is formed on sidewalls of an upper portion of the gate stack that is located above the plurality of semiconductor fins. The width of the gate spacer thus is not limited by the fin pitch, and can be optimized to improve the device performance.

Abstract: Certain embodiments of the present invention include a versatile and scalable process, “patterned regrowth,” that allows for the spatially controlled synthesis of lateral junctions between electrically conductive graphene and insulating h-BN, as well as between intrinsic and substitutionally doped graphene. The resulting films form mechanically continuous sheets across these heterojunctions. These embodiments represent an element of developing atomically thin integrated circuitry and enable the fabrication of electrically isolated active and passive elements embedded in continuous, one atom thick sheets, which may be manipulated and stacked to form complex devices at the ultimate thickness limit.

Abstract: In various embodiments, a method for processing a carrier is provided. The method for processing a carrier may include: forming a first catalytic metal layer over a carrier; forming a source layer over the first catalytic metal layer; forming a second catalytic metal layer over the source layer, wherein the thickness of the second catalytic metal layer is larger than the thickness of the first catalytic metal layer; and subsequently performing an anneal to enable diffusion of the material of the source layer forming an interface layer adjacent to the surface of the carrier from the diffused material of the source layer.

Abstract: Methods form structures to include a first pair of complementary transistors (having first and second transistors) and a second pair of complementary transistors (having third and fourth transistors). An active area of the first transistor contacts an active area of the second transistor along a first common edge that is straight, and an active area of the third transistor contacts an active area of the fourth transistor along a second common edge that is straight and parallel to the first common edge. The active area of the second transistor has a third edge, opposite the first common edge, that has a non-linear shape, and the active area of the third transistor has a fourth edge, opposite the second common edge, that has the same non-linear shape. The non-linear shape of the third edge faces and is inverted relative to the non-linear shape of the fourth edge.

Abstract: A low temperature poly-silicon thin film transistor and a manufacturing method thereof are disclosed. The method includes forming an active layer on a base substrate, forming an ohmic contact layer on the active layer through an atomic layer deposition process, and forming a source electrode and a drain electrode on the ohmic contact layer. The ohmic contact layer includes a plurality of conductive ionic layers and a plurality of monocrystalline silicon layers/poly-silicon layers. The source electrode and the drain electrode are in contact with the active layer through the ohmic contact layer.

Abstract: A method for manufacturing a semiconductor device includes providing a substrate structure having a substrate and a cavity in the substrate, epitaxially growing a SiGe nanowire in the cavity, and removing a portion of the substrate surrounding the SiGe nanowire to substantially expose a surface of the SiGe nanowire. The method further includes oxidizing the exposed surface of the SiGe nanowire to form an oxide layer, removing the oxide layer by etching, and repeating the oxidizing and removing steps to form a suspended germanium nanowire in the cavity.

Abstract: A tunnel field-effect transistor device includes a p-type GaN source layer, an n-type GaN drain layer, and an interlayer interfaced between the source-layer and the drain layer. In one example, the interlayer includes an Indium Nitride (InN) layer. In one example, the interlayer includes a graded Indium gallium nitride layer and an InN layer. In one example, the interlayer may include a graded Indium gallium nitride (InxGa1-xN) layer and an Indium gallium nitride (InGaN) layer. In one example, the tunnel field-effect transistor device includes an in-line configuration. In one example, the tunnel field-effect transistor device includes a side-wall configuration.

Abstract: A semiconductor device includes a source/drain feature disposed over a substrate. The source/drain feature includes a first nanowire, a second nanowire disposed over the first nanowire, a cladding layer disposed over the first nanowire and the second nanowire and a spacer layer extending from the first nanowire to the second nanowire. The device also includes a conductive feature disposed directly on the source/drain feature such that the conductive feature physically contacts the cladding layer and the spacer layer.

Abstract: A method of preventing a charge accumulation in the manufacturing process of a semiconductor device is provided. The method includes: forming a material layer on a substrate; patterning (or processing) the material layer; and forming a graphene layer before patterning the material layer, wherein the graphene layer is formed on a surface of the material layer or on a surface of the substrate under the material layer. The substrate may be an insulation substrate. In addition, the substrate may have a stacked structure including a plurality of layers.

Abstract: Embodiments of the invention describe a method for forming a nanowire structure on a substrate. According to one embodiment, the method includes a) depositing a first semiconductor layer on the substrate, b) etching the first semiconductor layer to form a patterned first semiconductor layer, c) forming a dielectric layer across the patterned first semiconductor layer, and d) depositing a second semiconductor layer on the patterned first semiconductor layer and on the dielectric layer. The method further includes e) repeating a)-d) at least once, f) following e), repeating a)-c) once, g) etching the patterned first semiconductor layers, the dielectric layers, and the second semiconductor layers to form a fin structure, and h) removing the patterned first semiconductor layers from the fin structure.

Abstract: According to one embodiment, a semiconductor device includes a first region having a first conductivity type in a semiconductor region; a second region having a second conductivity type in the semiconductor region; a gate electrode above a first part of the semiconductor region between the first region and the second region; a gate insulating layer between the first part and the gate electrode; a third region having the first conductivity type below the second region; and a fourth region across the second region and the third region and including a first impurity.

Abstract: A method for forming nanowires includes forming a plurality of epitaxial layers on a substrate, the layers including alternating material layers with high and low Ge concentration and patterning the plurality of layers to form fins. The fins are etched to form recesses in low Ge concentration layers to form pillars between high Ge concentration layers. The pillars are converted to dielectric pillars. A conformal material is formed in the recesses and on the dielectric pillars. The high Ge concentration layers are condensed to form hexagonal Ge wires with (111) facets. The (111) facets are exposed to form nanowires.

Abstract: A field effect transistor (FET) for an nFET and/or a pFET device including a fin having a stack of nanowire-like channel regions. The stack includes at least a first nanowire-like channel region and a second nanowire-like channel region stacked on the first nanowire-like channel region. The FET includes source and drain electrodes on opposite sides of the fin. The FET also includes a dielectric separation region including SiGe between the first and second nanowire-like channel regions extending completely from a surface of the second channel region facing the first channel region to a surface of the first channel region facing the second channel region. The FET includes a gate stack extending along a pair of sidewalls of the stack. The gate stack includes a gate dielectric layer and a metal layer on the gate dielectric layer. The metal layer does not extend between the first and second nanowire-like channel regions.

Abstract: A semiconductor device includes a gate positioned on a substrate; a nanosheet that extends through the gate, protrudes from a sidewall of the gate, and forms a recess between the substrate and the nanosheet; a dielectric spacer disposed in the recess; a source/drain contact positioned on a source/drain disposed on the substrate adjacent to the gate; an air gap spacer positioned along the sidewall of the gate and in contact with a dielectric material disposed on the nanosheet, the air gap spacer being in contact with the source/drain contact; and an interlayer dielectric (ILD) disposed on the air gap spacer.

Abstract: In a method for manufacturing a semiconductor device, a doped layer is formed in a substrate. A barrier layer that is in contact with the doped layer is formed. A semiconductor layer is formed over the substrate and the barrier layer. A fin structure is formed by patterning the semiconductor layer, the barrier layer, and the doped layer such that the fin structure includes a channel region including the semiconductor layer and a well region including the doped layer. An isolation insulating layer is formed such that a first portion of the fin structure protrudes from the isolation insulating layer and a second portion of the fin structure is embedded in the isolation insulating layer. A gate structure is formed over the fin structure and the isolation insulating layer.

Abstract: A complementary logic device includes i) a substrate, ii) a first semiconductor device located on the substrate and including a first channel layer, a carrier supply layer for supplying a carrier to the channel layer, and an upper cladding layer and a lower cladding layer respectively located at upper and lower portions of the channel layer, iii) a second semiconductor device located on the substrate and including a structure the same or similar to that of the first semiconductor device, iv) a source electrode located on the two semiconductors and made of a ferromagnetic body, v) a drain electrode located on the two semiconductors and made of a ferromagnetic body, and vi) a gate electrode located on the two semiconductors and located between the two electrodes so that a gate voltage is applied thereto to control a spin of electrons passing through the two channel layers.

Abstract: A method for forming semiconductor devices includes forming a highly doped region. A stack of alternating layers is formed on the substrate. The stack is patterned to form nanosheet structures. A dummy gate structure is formed over and between the nanosheet structures. An interlevel dielectric layer is formed. The dummy gate structures are removed. SG regions are blocked, and top sheets are removed from the nanosheet structures along the dummy gate trench. A bottommost sheet is released and forms a channel for a field effect transistor device by etching away the highly doped region under the nanosheet structure and layers in contact with the bottommost sheet. A gate structure is formed in and over the dummy gate trench wherein the bottommost sheet forms a device channel for the EG device.

Abstract: The present invention discloses a method of forming a high voltage junctionless device with drift region. The drift region formed between the semiconductor channel and the dielectric layer enables the high voltage junctionless device to exhibit higher punch-through voltages and high mobility with better performance and reliability.

Abstract: A method of making a carbon nanotube structure includes depositing a first oxide layer on a substrate and a second oxide layer on the first oxide layer; etching a trench through the second oxide layer; removing end portions of the first oxide layer and portions of the substrate beneath the end portions to form cavities in the substrate; depositing a metal in the cavities to form first body metal pads; disposing a carbon nanotube on the first body metal pads and the first oxide layer such that ends of the carbon nanotube contact each of the first body metal layers; depositing a metal to form second body metal pads on the first body metal pads at the ends of the carbon nanotube; and etching to release the carbon nanotube, first body metal pads, and second body metal pads from the substrate, first oxide layer, and second oxide layer.

Abstract: A semiconductor device may include the following elements: a first doped region; a second doped region, which contacts the first doped region; a third doped region, which contacts the first doped region; a first dielectric layer, which contacts the above-mentioned doped regions; a first gate member, which is conductive and comprises a first gate portion, a second gate portion, and a third gate portion, wherein the first gate portion contacts the first dielectric layer, wherein the second gate portion is positioned between the first gate portion and the third gate portion, and wherein a width of the second portion is unequal to a width of the third gate portion; a doped portion, which is positioned between the third gate portion and the third doped region; a second gate member; and a second dielectric layer, which is positioned between the third gate portion and the second gate member.

Abstract: A method of making a semiconductor device includes forming a first fin in a first semiconducting material layer disposed over a substrate, the first semiconducting material layer comprising an element in a first concentration; and forming a second fin in a second semiconducting material layer disposed over the substrate and adjacent to the first semiconducting material layer, the second semiconducting material layer comprising the element in a second concentration; wherein the first concentration is different than the second concentration.

Abstract: A polymer based photo-detector has photoresponsivity in Ultraviolet, Visible, Near and Mid Infrared regions. The photo-detector comprises a single layer of polyvinyl alcohol (PVA) as a photoactive layer; with no additional buffer layer for accepting Ultraviolet, Visible and Infrared radiation as well as no buffer layer to block charge carrier injection. The PVA layer's photoresponsivity is extended from Ultraviolet to Near Infrared by changing its nano-morphology on a low thermal device structure. The primarily photo-generated charge carriers diffuse through the amorphous part of the polymer layer and split into charge carriers on the electrodes or by the charge traps in the layer. The charge carrier generation is in the picosecond range; thus the exciton and Polaron drift diffusion cause electrical conduction of the polymer layer under Ultraviolet illumination.

Abstract: A transistor device includes an array of fin structures arranged on a substrate, each of the fin structures being vertically alternating stacks of a first isoelectric point material having a first isoelectric point and a second isoelectric point material having a second isoelectric point that is different than the first isoelectric point; one or more carbon nanotubes (CNTs) suspended between the fin structures and contacting a side surface of the second isoelectric point material in the fin structures; a gate wrapped around the array of CNTs; and source and drain contacts arranged over the fin structures; wherein each of the fin structures have a trapezoid shape or parallel sides that are oriented about 90° with respect to the substrate.

Abstract: Transistor devices and methods for forming transistor devices are provided. A transistor device includes a semiconductor substrate and a device layer. The device layer includes a source region and a drain region connected by a suspended nanowire channel. First and second etch stop layers are respectively arranged beneath the source region and the drain region. Each of the etch stop layers forms a support structure interposed between the semiconductor substrate and the respective source and drain regions.

Abstract: A fin field effect transistor (FinFET) device includes a substrate and a template material over the substrate. The template material absorbs lattice mismatches with the substrate. The FinFET device also includes a barrier material over the template material. The barrier material is free of point defects. The FinFET device further includes a channel material over the barrier material.

Abstract: A semiconductor device is provided as follows. A first nanowire is disposed on a substrate. The first nanowire is extended in a first direction and spaced apart from the substrate. A gate electrode surrounds a periphery of the first nanowire. The gate electrode is extended in a second direction intersecting the first direction. A gate spacer is formed on a sidewall of the gate electrode. The gate spacer includes an inner sidewall and an outer sidewall facing each other. The inner sidewall of the gate spacer faces the sidewall of the gate electrode. An end portion of the first nanowire is protruded from the outer sidewall of the gate spacer. A source/drain epitaxial layer is disposed on at least one side of the gate electrode. The source/drain is connected to the protruded end portion of the first nanowire.

Abstract: A method for fabricating a semiconductor device comprises forming a sacrificial layer of a first semiconductor material on a substrate, a layer of a second semiconductor material on the sacrificial layer, and a layer of a third semiconductor material on the layer of the second semiconductor material. Portions of the layer of the deposited material are removed to form a first nanowire arranged on the sacrificial fin and a second nanowire arranged on the first nanowire. An oxidizing process is performed that forms a first layer of oxide material on exposed portions of the second nanowire and a second layer of oxide material on exposed portions of the sacrificial fin, the first layer of oxide material having a first thickness and the second layer of oxide material having a second thickness, where the first thickness is less than the second thickness.

Abstract: A method for fabricating a transistor is provided. The method includes providing a semiconductor substrate; and forming at least a nanowire suspending in the semiconductor substrate. The method also includes forming a channel layer surrounding the nanowire; and forming a contact layer surrounding the channel layer. Further, the method includes forming a trench exposing the channel layer and surrounding the channel layer in the contact layer; and forming a potential barrier layer on the bottom of the trench and surrounding the channel layer. Further, the method also includes forming a gate structure surrounding the potential barrier layer and covering portions of the contact layer; and forming a source and a drain region on the contact layer at two sides of the gate structure, respectively.

Abstract: A device includes a substrate, insulation regions extending into the substrate, a first semiconductor region between the insulation regions and having a first valence band, and a second semiconductor region over and adjoining the first semiconductor region. The second semiconductor region has a compressive strain and a second valence band higher than the first valence band. The second semiconductor region includes an upper portion higher than top surfaces of the insulation regions to form a semiconductor fin, and a lower portion lower than the top surfaces of the insulation regions. The upper portion and the lower portion are intrinsic. A semiconductor cap adjoins a top surface and sidewalls of the semiconductor fin. The semiconductor cap has a third valence band lower than the second valence band.

Abstract: A threshold voltage tuning approach for forming a stacked nanowire gate-all around pFET is provided. In the present application, selective condensation (i.e., oxidation) is used to provide a threshold voltage shift in silicon germanium alloy nanowires. The threshold voltage shift is well controlled because both underlying parameters which govern the final germanium content, i.e., nanowire width and amount of condensation, are well controlled by the selective condensation process. The present application can address the problem of width quantization in stacked nanowire FETs by offering various device options.

Abstract: A starting non-planar semiconductor structure is provided having a semiconductor substrate, raised semiconductor structures coupled to the substrate, and a layer of isolation material(s) surrounding the raised structures. The isolation layer is recessed to expose about 40 nm to about 70 nm of the raised structures. The increased height of the exposed raised structures, compared to conventional, allows for a taller gate and taller spacers, which reduces undercut under the spacers and short-channel effects from the loss of isolation material in fabrication.

Abstract: The present disclosure relates to an intra-band tunnel FET, which has a symmetric FET that is able to provide for a high drive current. In some embodiments, the disclosed intra-band tunnel FET has a source region having a first doping type and a drain region having the first doping type. The source region and the drain region are separated by a channel region. A gate region may generate an electric field that varies the position of a valence band and/or a conduction band in the channel region. By controlling the position of the valence band and/or the conduction band of the channel region, quantum mechanical tunneling of charge carries between the conduction band in the source region and in the drain region or between the valence band in the source region and in the drain region can be controlled.

Abstract: A semiconductor device includes a substrate, a pair of source/drain units, and a semiconductor sheet unit. The substrate includes a well region. The source/drain units are disposed above the well region. The semiconductor sheet unit is disposed substantially vertically, interconnects the source/drain units, and defines a cross-sectional shape unit in a top view. The cross-sectional shape unit includes a plurality of cross-sections that have substantially the same shape and different sizes.

Abstract: Self-assembled tunable networks of microscopic polymer fibers ranging from wavy colloidal “fur” to highly interconnected networks are created from polymer systems and an applied electric field. The networks emerge via dynamic self-assembly in an alternating (ac) electric field from a non-aqueous suspension of “sticky” polymeric colloidal particles with a controlled degree of polymerization. The resulting architectures are tuned by the frequency and amplitude of the electric field and surface properties of the particles.

Abstract: The present invention provides some methods for forming at least two different nanowire structures with different diameters on one substrate. Since the diameter of the nanowire structure will influence the threshold voltage (Vt) and the drive currents of a nanowire field effect transistor, in this invention, at least two nanowire structures with different diameters can be formed on one substrate. Therefore, in the following steps, these nanowire structures can be applied in different nanowire field effect transistors with different Vt and drive currents. This way, the flexibility of the nanowire field effect transistors can be improved.

Abstract: Transistors suitable for high voltage and high frequency operation are disclosed. A nanowire is disposed vertically or horizontally on a substrate. A longitudinal length of the nanowire is defined into a channel region of a first semiconductor material, a source region electrically coupled with a first end of the channel region, a drain region electrically coupled with a second end of the channel region, and an extrinsic drain region disposed between the channel region and drain region. The extrinsic drain region has a wider bandgap than that of the first semiconductor. A gate stack including a gate conductor and a gate insulator coaxially wraps completely around the channel region, drain and source contacts similarly coaxially wrap completely around the drain and source regions.

Abstract: A method of forming a semiconductor device includes: forming a superlattice structure atop the top surface of a substrate, wherein the superlattice structure comprises a plurality of first layers and a corresponding plurality of second layers alternatingly arranged in a plurality of stacked pairs; forming a lateral etch stop layer by epitaxial deposition of a material of the first layer or the second layer of the superlattice structure atop a sidewall of the superlattice structure, or by selectively oxidizing edges of the first layers and second layers of the superlattice structure; subsequently forming a source region adjacent a first end of the superlattice structure and a drain region adjacent a second opposing end of the superlattice structure; and selectively etching the superlattice structure to remove each of the first layers or each of the second layers to form a plurality of voids in the superlattice structure.