Abstract: Techniques are disclosed for forming group III material-nitride (III-N) microelectromechanical systems (MEMS) structures on a group IV substrate, such as a silicon, silicon germanium, or germanium substrate. In some cases, the techniques include forming a III-N layer on the substrate and optionally on shallow trench isolation (STI) material, and then releasing the III-N layer by etching to form a free portion of the III-N layer suspended over the substrate. The techniques may include, for example, using a wet etch process that selectively etches the substrate and/or STI material, but does not etch the III-N material (or etches the III-N material at a substantially slower rate). Piezoresistive elements can be formed on the III-N layer to, for example, detect vibrations or deflection in the free/suspended portion of the III-N layer. Accordingly, MEMS sensors can be formed using the techniques, such as accelerometers, gyroscopes, and pressure sensors, for example.

Abstract: Techniques are disclosed for gallium nitride (GaN) oxide isolation and formation of GaN transistor structures on a substrate. In some cases, the GaN transistor structures can be used for system-on-chip integration of high-voltage GaN front-end radio frequency (RF) switches on a bulk silicon substrate. The techniques can include, for example, forming multiple fins in a substrate, depositing the GaN layer on the fins, oxidizing at least a portion of each fin in a gap below the GaN layer, and forming one or more transistors on and/or from the GaN layer. In some cases, the GaN layer is a plurality of GaN islands, each island corresponding to a given fin. The techniques can be used to form various non-planar isolated GaN transistor architectures having a relatively small form factor, low on-state resistance, and low off-state leakage, in some cases.

Abstract: Crystalline heterostructures including an elevated fin structure extending from a sub-fin structure over a substrate. Devices, such as III-V transistors, may be formed on the raised fin structures while silicon-based devices (e.g., transistors) may be formed in other regions of the silicon substrate. A sub-fin isolation material localized to a transistor channel region of the fin structure may reduce source-to-drain leakage through the sub-fin, improving electrical isolation between source and drain ends of the fin structure. Subsequent to heteroepitaxially forming the fin structure, a portion of the sub-fin may be laterally etched to undercut the fin. The undercut is backfilled with sub-fin isolation material. A gate stack is formed over the fin. Formation of the sub-fin isolation material may be integrated into a self-aligned gate stack replacement process.

Abstract: A method including forming a non-planar conducting channel of a device between junction regions on a substrate, the substrate including a blocking material beneath the channel, the blocking material including a property to inhibit carrier leakage; and forming a gate stack on the channel, the gate stack including a dielectric material and a gate electrode. A method including forming a buffer material on a semiconductor substrate, the buffer material including a semiconductor material including a different lattice structure than the substrate; forming a blocking material on the buffer material, the blocking material including a property to inhibit carrier leakage; and forming a transistor device on the substrate. An apparatus including a non-planar multi-gate device on a substrate including a transistor device including a channel disposed on a substrate including a blocking material beneath the channel, the blocking material including a property to inhibit carrier leakage.

Abstract: Crystalline heterostructures including an elevated crystalline structure extending from one or more trenches in a trench layer disposed over a crystalline substrate are described. In some embodiments, an interfacial layer is disposed over a silicon substrate surface. The interfacial layer facilitates growth of the elevated structure from a bottom of the trench at growth temperatures that may otherwise degrade the substrate surface and induce more defects in the elevated structure. The trench layer may be disposed over the interfacial layer with a trench bottom exposing a portion of the interfacial layer. Arbitrarily large merged crystal structures having low defect density surfaces may be overgrown from the trenches. Devices, such as III-N transistors, may be further formed on the raised crystalline structures while silicon-based devices (e.g., transistors) may be formed in other regions of the silicon substrate.

Abstract: An apparatus including a three-dimensional semiconductor body including a channel region and junction regions disposed on opposite sides of the channel region, the three-dimensional semiconductor body including a plurality of nanowires including a germanium material disposed in respective planes separated in the junction regions by a second material, wherein a lattice constant of the second material is similar to a lattice constant of the germanium material; and a gate stack disposed on the channel region, the gate stack including a gate electrode disposed on a gate dielectric. A method of including forming a plurality of nanowires in separate planes on a substrate, each of the plurality of nanowires including a germanium material and separated from an adjacent nanowire by a sacrificial material; disposing a gate stack on the plurality of nanowires in a designated channel region, the gate stack including a dielectric material and a gate electrode.

Abstract: Embodiments of the present disclosure are directed towards an integrated circuit (IC) die. In embodiments, an IC die may include a semiconductor substrate, a group III-Nitride or II-VI wurtzite layer disposed over the semiconductor substrate, and a plurality of buffer structures at least partially embedded in the group III-Nitride or II-VI wurtzite layer. In some embodiments, each of the plurality of buffer structures may include a central member disposed over the semiconductor substrate, a lower lateral member disposed over the semiconductor substrate and extending laterally away from the central member, and an upper lateral member disposed over the central member and extending laterally from the central member in an opposite direction from the lower lateral member. The plurality of buffer structures may be positioned in a staggered arrangement to terminate defects of the group III-Nitride or II-VI wurtzite layer. Other embodiments may be described and/or claimed.

Abstract: The present description relates to n-channel gallium nitride transistors which include a recessed gate electrode, wherein the polarization layer between the gate electrode and the gallium nitride layer is less than about 1 nm. In additional embodiments, the n-channel gallium nitride transistors may have an asymmetric configuration, wherein a gate-to drain length is greater than a gate-to-source length. In further embodiment, the n-channel gallium nitride transistors may be utilized in wireless power/charging devices for improved efficiencies, longer transmission distances, and smaller form factors, when compared with wireless power/charging devices using silicon-based transistors.

Abstract: An integrated circuit die includes a quad-gate device nanowire of channel material for a transistor (e.g., single material or stack to be a channel of a MOS device) formed by removing a portion of a sub-fin material from below the channel material, where the sub-fin material was grown in an aspect ration trapping (ART) trench. In some cases, in the formation of such nanowires, it is possible to remove the defective fin material or area under the channel. Such removal isolates the fin channel, removes the fin defects and leakage paths, and forms the nanowire of channel material having four exposed surfaces upon which gate material may be formed.

Abstract: Embodiments of the present disclosure are directed towards an integrated circuit (IC) die. In embodiments, an IC die may include a semiconductor substrate, a group III-Nitride or II-VI wurtzite layer disposed over the semiconductor substrate, and a plurality of buffer structures at least partially embedded in the group III-Nitride or II-VI wurtzite layer. In some embodiments, each of the plurality of buffer structures may include a central member disposed over the semiconductor substrate, a lower lateral member disposed over the semiconductor substrate and extending laterally away from the central member, and an upper lateral member disposed over the central member and extending laterally from the central member in an opposite direction from the lower lateral member. The plurality of buffer structures may be positioned in a staggered arrangement to terminate defects of the group III-Nitride or II-VI wurtzite layer. Other embodiments may be described and/or claimed.

Abstract: An embodiment includes a device comprising: a fin structure including an upper portion and a lower portion, the upper portion having a bottom surface directly contacting an upper surface of the lower portion; wherein (a) the lower portion is included in a trench having an aspect ratio (depth to width) of at least 2:1; (b) the bottom surface has a bottom maximum width and the upper surface has an upper maximum width that is greater the bottom maximum width; (c) the bottom surface covers a middle portion of the upper surface but does not cover lateral portions of the upper surface; and (d) the upper portion includes an upper III-V material and the lower portion includes a lower III-V material different from the upper III-V material. Other embodiments are described herein.

Abstract: An embodiment includes a device comprising: first and second fins adjacent one another and each including channel and subfin layers, the channel layers having bottom surfaces directly contacting upper surfaces of the subfin layers; wherein (a) the bottom surfaces are generally coplanar with one another and are generally flat; (b) the upper surfaces are generally coplanar with one another and are generally flat; and (c) the channel layers include an upper material and the subfin layers include a lower III-V material different from the upper III-V material. Other embodiments are described herein.

Abstract: A III-N semiconductor channel is compositionally graded between a transition layer and a III-N polarization layer. In embodiments, a gate stack is deposited over sidewalls of a fin including the graded III-N semiconductor channel allowing for formation of a transport channel in the III-N semiconductor channel adjacent to at least both sidewall surfaces in response to a gate bias voltage. In embodiments, a gate stack is deposited completely around a nanowire including a III-N semiconductor channel compositionally graded to enable formation of a transport channel in the III-N semiconductor channel adjacent to both the polarization layer and the transition layer in response to a gate bias voltage.

Abstract: Techniques are disclosed for forming a defect-free semiconductor structure on a dissimilar substrate with a multi-aspect ratio mask. The multi-aspect ratio mask comprises a first, second, and third layer formed on a substrate. The second layer has a second opening wider than a first opening and a third opening in the first and third layers, respectively. All three openings are centered along a common central axis. A semiconductor material is grown from the top surface of the substrate and laterally onto the top surface of the first layer within the second opening. The semiconductor material disposed within and vertically below the third opening is etched by using the third layer as an etch mask so that the remaining material that laterally overflowed onto the top surface of the first layer forms a remaining structure.

Abstract: Embodiments of the invention include nanowire and nanoribbon transistors and methods of forming such transistors. According to an embodiment, a method for forming a microelectronic device may include forming a multi-layer stack within a trench formed in a shallow trench isolation (STI) layer. The multi-layer stack may comprise at least a channel layer, a release layer formed below the channel layer, and a buffer layer formed below the channel layer. The STI layer may be recessed so that a top surface of the STI layer is below a top surface of the release layer. The exposed release layer from below the channel layer by selectively etching away the release layer relative to the channel layer.

Abstract: Trenches (and processes for forming the trenches) are provided that reduce or prevent crystaline defects in selective epitaxial growth of type III-V or Germanium (Ge) material (e.g., a “buffer” material) from a top surface of a substrate material. The defects may result from collision of selective epitaxial sidewall growth with oxide trench sidewalls. Such trenches include (1) a trench having sloped sidewalls at an angle of between 40 degrees and 70 degrees (e.g., such as 55 degrees) with respect to a substrate surface; and/or (2) a combined trench having an upper trench over and surrounding the opening of a lower trench (e.g., the lower trench may have the sloped sidewalls, short vertical walls, or tall vertical walls). These trenches reduce or prevent defects in the epitaxial sidewall growth where the growth touches or grows against vertical sidewalls of a trench it is grown in.

Abstract: III-N semiconductor heterostructures including a raised III-N semiconductor structures with inclined sidewall facets are described. In embodiments, lateral epitaxial overgrowth favoring semi-polar inclined sidewall facets is employed to bend crystal defects from vertical propagation to horizontal propagation. In embodiments, arbitrarily large merged III-N semiconductor structures having low defect density surfaces may be overgrown from trenches exposing a (100) surface of a silicon substrate. III-N devices, such as III-N transistors, may be further formed on the raised III-N semiconductor structures while silicon-based transistors may be formed in other regions of the silicon substrate.

Abstract: Transistors or transistor layers include an InAlN and AlGaN bi-layer capping stack on a 2DEG GaN channel, such as for GaN MOS structures on Si substrates. The GaN channel may be formed in a GaN buffer layer or stack, to compensate for the high crystal structure lattice size and coefficient of thermal expansion mismatch between GaN and Si. The bi-layer capping stack an upper InAlN layer on a lower AlGaN layer to induce charge polarization in the channel, compensate for poor composition uniformity (e.g., of Al), and compensate for rough surface morphology of the bottom surface of the InAlN material. It may lead to a sheet resistance between 250 and 350 ohms/sqr. It may also reduce bowing of the GaN on Si wafers during growth of the layer of InAlN material, and provide a AlGaN setback layer for etching the InAlN layer in the gate region.

Abstract: An insulating layer is conformally deposited on a plurality of mesa structures in a trench on a substrate. The insulating layer fills a space outside the mesa structures. A nucleation layer is deposited on the mesa structures. A III-V material layer is deposited on the nucleation layer. The III-V material layer is laterally grown over the insulating layer.

Abstract: A fin over an insulating layer on a substrate having a first crystal orientation is modified to form a surface aligned along a second crystal orientation. A device layer is deposited over the surface of the fin aligned along the second crystal orientation.