Abstract: Embodiments of the invention include microelectronic devices, resonators, and methods of fabricating the microelectronic devices. In one embodiment, a microelectronic device includes a substrate and a plurality of cavities integrated with the substrate. A plurality of vertically oriented resonators are formed with each resonator being positioned in a cavity. Each resonator includes a crystalline or single crystal piezoelectric film.

Abstract: A surface acoustic wave (SAW) resonator structure, an integrated circuit, and a method of fabricating a SAW structure are provided. The method includes epitaxially growing a crystalline aluminum nitride piezoelectric film layer on a substrate; and deposing a plurality of electrodes on the piezoelectric film layer. The SAW structure includes a substrate, a piezoelectric film on the substrate, and a plurality of electrodes on the piezoelectric film.

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 integrated circuit film bulk acoustic resonator (FBAR) device having multiple resonator thicknesses is formed on a common substrate in a stacked configuration. In an embodiment, a seed layer is deposited on a substrate, and one or more multi-layer stacks are deposited on the seed layer, each multi-layer stack having a first metal layer deposited on a first sacrificial layer, and a second metal layer deposited on a second sacrificial layer. The second sacrificial layer can be removed and the resulting space is filled in with a piezoelectric material, and the first sacrificial layer can be removed to release the piezoelectric material from the substrate and suspend the piezoelectric material above the substrate. More than one multi-layer stack can be added, each having a unique resonant frequency. Thus, multiple resonator thicknesses can be achieved on a common substrate, and hence, multiple resonant frequencies on that same substrate.

Abstract: A gate stack structure is disclosed for inhibiting charge leakage in III-V transistor devices. The techniques are particularly well-suited for use in enhancement-mode MOSHEMTs, but can also be used in other transistor designs susceptible to charge spillover and unintended channel formation in the gate stack. In an example embodiment, the techniques are realized in a transistor having a III-N gate stack over a gallium nitride (GaN) channel layer. The gate stack is configured with a relatively thick barrier structure and wide bandgap III-N materials to prevent or otherwise reduce channel charge spillover resulting from tunneling or thermionic processes at high gate voltages. The barrier structure is configured to manage lattice mismatch conditions, so as to provide a robust high performance transistor design. In some cases, the gate stack is used in conjunction with an access region polarization layer to induce two-dimensional electron gas (2DEG) in the channel layer.

Abstract: Techniques are disclosed for producing integrated circuit structures that include one or more geometrically manipulated polarization layers. The disclosed structures can be formed, for instance, using spacer erosion methods in which more than one type of spacer material is deposited on a polarization layer, and the spacer materials and underlying regions of the polarization layer may then be selectively etched in sequence to provide a desired profile shape to the polarization layer. Geometrically manipulated polarization layers as disclosed herein may be formed to be thinner in regions closer to the gate than in other regions, in some embodiments. The disclosed structures may eliminate the need for a field plate and may also be configured with polarization layers that are shorter in lateral length than polarization layers of uniform thickness without sacrificing performance capability. Additionally, the disclosed techniques may provide increased voltage breakdown without sacrificing Ron.

Abstract: A bulk acoustic resonator architecture is fabricated by epitaxially forming a piezoelectric film on a top surface of post formed from an underlying substrate. In some cases, the acoustic resonator is fabricated to filter multiple frequencies. In some such cases, the resonator device includes two different resonator structures on a single substrate, each resonator structure configured to filter a desired frequency. Including two different acoustic resonators in a single RF acoustic resonator device enables that single device to filter two different frequencies in a relatively small footprint.

Abstract: Techniques are disclosed for fabricating co-planar p-channel and n-channel gallium nitride (GaN)-based transistors on silicon (Si). In accordance with some embodiments, a Si substrate may be patterned with recessed trenches located under corresponding openings formed in a dielectric layer over the substrate. Within each recessed trench, a stack including a buffer layer, a GaN or indium gallium nitride (InGaN) layer, and a polarization layer may be selectively formed, in accordance with some embodiments. The p-channel stack further may include another GaN or InGaN layer over its polarization layer, with source/drain (S/D) portions adjacent the m-plane or a-plane sidewalls of that GaN or InGaN layer. The n-channel may include S/D portions over its GaN or InGaN layer, within its polarization layer, in accordance with some embodiments.

Abstract: Embodiments of the present disclosure propose two methods for integrating vacancy centers (VCs) on semiconductor substrates for forming VC-based spin qubit devices. The first method is based on using a self-assembly process for integrating VC islands on a semiconductor substrate. The second method is based on using a buffer layer of a III-N semiconductor material over a semiconductor substrate, and then integrating VC islands in an insulating carbon-based material such as diamond that is either grown as a layer on the III-N buffer layer or grown in the openings formed in the III-N buffer layer. Integration of VC islands on semiconductor substrates typically used in semiconductor manufacturing according to any of these methods may provide a substantial improvement with respect to conventional approaches to building VC-based spin qubit devices and may promote wafer-scale integration of VC-based spin qubits for use in quantum computing devices.

Abstract: Methods and apparatus for semiconductor manufacture are disclosed. An example apparatus includes a Gallium Nitride (GaN) substrate; a p-type GaN region positioned on the GaN substrate; a p-type Indium Nitride (InN) region positioned on the GaN substrate and sharing an interface with the p-type GaN region; and a n-type Indium Gallium Nitride (InGaN) region positioned on the GaN substrate and sharing an interface with the p-type InN region.

Abstract: Techniques are disclosed for forming high frequency film bulk acoustic resonator (FBAR) devices that include a bottom electrode formed of a two-dimensional electron gas (2DEG). The disclosed FBAR devices may be implemented with various group III-nitride (III-N) materials, and in some cases, the 2DEG may be formed at a heterojunction of two epitaxial layers each formed of III-N materials, such as a gallium nitride (GaN) layer and an aluminum nitride (AlN) layer. The 2DEG bottom electrode may be able to achieve similar or increased carrier transport as compared to an FBAR device having a bottom electrode formed of metal. Additionally, in some embodiments where AlN is used as the piezoelectric material for the FBAR device, the AlN may be epitaxially grown which may provide increased performance as compared to piezoelectric material that is deposited by traditional sputtering techniques.

Abstract: Techniques are disclosed for forming integrated circuit single-flipped resonator devices that include an electrode formed of a two-dimensional electron gas (2 DEG). The disclosed resonator devices may be implemented with various group III-nitride (III-N) materials, and in some cases, the 2 DEG may be formed at a heterojunction of two epitaxial layers each formed of III-N materials, such as a gallium nitride (GaN) layer and an aluminum nitride (AlN) layer. The 2 DEG electrode may be able to achieve similar or increased carrier transport as compared to a resonator device having an electrode formed of metal. Additionally, in some embodiments where AlN is used as the piezoelectric material for the resonator device, the AlN may be epitaxially grown which may provide increased performance as compared to piezoelectric material that is deposited by traditional sputtering techniques.

Abstract: Integrated circuit transistor structures are provided that may reduce capacitive parasitics by using metal on both sides (top and bottom) of a given integrated circuit transistor device layer. For example, in an embodiment, the drain metal interconnect is provided above the transistor device layer, and the source metal interconnect is provided below the transistor layer. Such a configuration reduces the parasitic capacitance not only between the source and drain metal interconnect layers, but also between the neighboring conductors of the drain metal interconnect layer, because the number of pass-thru conductors in the drain metal interconnect layer to access an upper conductor in the source metal interconnect layer is reduced. In other embodiments, the source metal interconnect remains above the transistor device layer, and the drain metal interconnect is moved to below the transistor device layer, to provide similar benefits. Techniques apply equally to any transistor type, including FETs and BJTs.

Abstract: Transistors including doped heteroepitaxial III-N source/drain crystals. In embodiments, transistors including a group IV or group III-V channel crystal employ n+ doped III-N source/drain structures on either side of a gate stack. Lateral tensile strain of the channel crystal may result from lattice mismatch between the channel crystal and the III-N source/drain crystals. In embodiments, an amorphous material is employed to limit growth of III-N material to only a single channel crystal facet, allowing a high quality monocrystalline source/drain to form that is capable of sustaining significant stress. In some embodiments, an n+ III-N source/drain crystal is grown on a (110) or (111) surface of a silicon channel crystal fabricated into a fin structure to form a tensile strained NMOS finFET.

Abstract: Techniques are disclosed for forming high frequency film bulk acoustic resonator (FBAR) devices having multiple resonator thicknesses on a common substrate. A piezoelectric stack is formed in an STI trench and overgrown onto the STI material. In some cases, the piezoelectric stack can include epitaxially grown AlN. In some cases, the piezoelectric stack can include single crystal (epitaxial) AlN in combination with polycrystalline (e.g., sputtered) AlN. The piezoelectric stack thus forms a central portion having a first resonator thickness and end wings extending from the central portion having a different resonator thickness. Each wing may also have different thicknesses. Thus, multiple resonator thicknesses can be achieved on a common substrate, and hence, multiple resonant frequencies on that same substrate. The end wings can have metal electrodes formed thereon, and the central portion can have a plurality of IDT electrodes patterned thereon.

Abstract: A semiconductor structure including a group III-N semiconductor material is disposed on a silicon substrate. A group III-N transistor structure is disposed on the group III-N semiconductor material. A well is disposed in the silicon substrate. The well has a first conductivity type. A doped region is disposed in the well. The doped region has a second conductivity type that is opposite to the first conductivity type. A first electrode is connected to the well of the second conductivity type and a second electrode is connected to the doped region having a first conductivity type. The well and the doped region form a PN diode. The well or the doped region is connected to the raised drain structure of the group III-N transistor.

Abstract: Techniques are disclosed for forming integrated circuit film bulk acoustic resonator (FBAR) devices having multiple resonator thicknesses on a common substrate. A piezoelectric stack is formed in an STI trench and overgrown onto the STI material. In some cases, the piezoelectric stack can include epitaxially grown AlN. In some cases, the piezoelectric stack can include single crystal (epitaxial) AlN in combination with polycrystalline (e.g., sputtered) AlN. The piezoelectric stack thus forms a central portion having a first resonator thickness and end wings extending from the central portion and having a different resonator thickness. Each wing may also have different thicknesses from one another. Thus, multiple resonator thicknesses can be achieved on a common substrate, and hence, multiple resonant frequencies on that same substrate. The end wings can have metal electrodes formed thereon, and the central portion can have a plurality of IDT electrodes patterned thereon.

Abstract: Techniques are disclosed for forming Schottky diodes on semipolar planes of group III-nitride (III-N) material structures. A lateral epitaxial overgrowth (LEO) scheme may be used to form the group III-N material structures upon which Schottky diodes can then be formed. The LEO scheme for forming III-N structures may include forming shallow trench isolation (STI) material on a semiconductor substrate, patterning openings in the STI, and growing the III-N material on the semiconductor substrate to form structures that extend through and above the STI openings, for example. A III-N structure may be formed using only a single STI opening, where such a III-N structure may have a triangular prism-like shape above the top plane of the STI layer. Further processing can include forming the gate (e.g., Schottky gate) and tied together source/drain regions on semipolar planes (or sidewalls) of the III-N structure to form a two terminal Schottky diode.

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: Methods and apparatus to form GaN-based transistors during back-end-of-line processing are disclosed. An example integrated circuit includes a first transistor formed on a first semiconductor substrate. The example integrated circuit includes a dielectric material formed on the first semiconductor substrate. The dielectric material extends over the first transistor. The example integrated circuit further includes a second semiconductor substrate formed on the dielectric material. The example integrated circuit also includes a second transistor formed on the second semiconductor substrate.