Abstract: Methods and apparatus to form silicon-based transistors on group III-nitride materials using aspect ratio trapping are disclosed. An example integrated circuit includes a group III-nitride substrate and a fin of silicon formed on the group III-nitride substrate. The integrated circuit further includes a first transistor formed on the fin of silicon and a second transistor formed on the group III-nitride substrate.

Abstract: Integrated circuit structures configured with low loss transmission lines are disclosed. The structures are implemented with group III-nitride (III-N) semiconductor materials, and are well-suited for use in radio frequency (RF) applications where high frequency signal loss is a concern. The III-N materials are effectively used as a conductive ground shield between a transmission line and the underlying substrate, so as to significantly suppress electromagnetic field penetration at the substrate. In an embodiment, a group III-N polarization layer is provided over a gallium nitride layer, and an n-type doped layer of indium gallium nitride (InzGa1-zN) is provided over or adjacent to the polarization layer, wherein z is in the range of 0.0 to 1.0. In addition to providing transmission line ground shielding in some locations, the III-N materials can also be used to form one or more active and/or passive components (e.g., power amplifier, RF switch, RF filter, RF diode, etc).

Abstract: III-N semiconductor heterostructures on III-N epitaxial islands laterally overgrown from a mesa of a silicon substrate. An IC may include a III-N semiconductor device disposed on the III-N epitaxial island overhanging the silicon mesa and may further include a silicon-based MOSFET monolithically integrated with the III-N device. Lateral epitaxial overgrowth from silicon mesas may provide III-N semiconductor regions of good crystal quality upon which transistors or other active semiconductor devices may be fabricated. Overhanging surfaces of III-N islands may provide multiple device layers on surfaces of differing polarity. Spacing between separate III-N islands may provide mechanical compliance to an IC including III-N semiconductor devices. Undercut of the silicon mesa may be utilized for transfer of III-N epitaxial islands to alternative substrates.

Abstract: Techniques are disclosed for forming resonator devices using epitaxially grown piezoelectric films. Given the epitaxy, the films are single crystal or monocrystalline. In some cases, the piezoelectric layer of the resonator device may be an epitaxial III-V layer such as an Aluminum Nitride, Gallium Nitride, or other group III material-nitride (III-N) compound film grown as a part of a single crystal III-V material stack. In an embodiment, the III-V material stack includes, for example, a single crystal AlN layer and a single crystal GaN layer, although any other suitable single crystal piezoelectric materials can be used. An interdigitated transducer (IDT) electrode is provisioned on the piezoelectric layer and defines the operating frequency of the filter. A plurality of the resonator devices can be used to enable filtering specific different frequencies on the same substrate (by varying dimensions of the IDT electrodes).

Abstract: Semiconductor devices including an elevated or raised doped crystalline structure extending from a device layer are described. In embodiments, III-N transistors include raised crystalline n+ doped source/drain structures on either side of a gate stack. In embodiments, an amorphous material is employed to limit growth of polycrystalline source/drain material, allowing a high quality source/drain doped crystal to grow from an undamaged region and laterally expand to form a low resistance interface with a two-degree electron gas (2DEG) formed within the device layer. In some embodiments, regions of damaged GaN that may spawn competitive polycrystalline overgrowths are covered with the amorphous material prior to commencing raised source/drain growth.

Abstract: A single fin or a pair of co-integrated n- and p-type single crystal electronic device fins are epitaxially grown from a substrate surface at a bottom of one or a pair of trenches formed between shallow trench isolation (STI) regions. The fin or fins are patterned and the STI regions are etched to form a height of the fin or fins extending above etched top surfaces of the STI regions. The fin heights may be at least 1.5 times their width. The exposed sidewall surfaces and a top surface of each fin is epitaxially clad with one or more conformal epitaxial materials to form device layers on the fin. Prior to growing the fins, a blanket buffer epitaxial material may be grown from the substrate surface; and the fins grown in STI trenches formed above the blanket layer. Such formation of fins reduces defects from material interface lattice mismatches.

Abstract: The present description relates to a gallium nitride transistor which includes at least one source/drain structure having low contact resistance between a 2D electron gas of the gallium nitride transistor and the source/drain structure. The low contact resistance may be a result of at least a portion of the source/drain structure being a single-crystal structure abutting the 2D electron gas. In one embodiment, the single-crystal structure is grown with a portion of a charge inducing layer of the gallium nitride transistor acting as a nucleation site.

Abstract: III-N semiconductor heterostructures on III-N epitaxial islands laterally overgrown from a mesa of a silicon substrate. An IC may include a III-N semiconductor device disposed on the III-N epitaxial island overhanging the silicon mesa and may further include a silicon-based MOSFET monolithically integrated with the III-N device. Lateral epitaxial overgrowth from silicon mesas may provide III-N semiconductor regions of good crystal quality upon which transistors or other active semiconductor devices may be fabricated. Overhanging surfaces of III-N islands may provide multiple device layers on surfaces of differing polarity. Spacing between separate III-N islands may provide mechanical compliance to an IC including III-N semiconductor devices. Undercut of the silicon mesa may be utilized for transfer of III-N epitaxial islands to alternative substrates.

Abstract: Embodiments of this disclosure are directed to a multi-gate gallium nitride (GaN) transistor and methods of making the same. The multi-gate GaN transistor includes a gallium nitride layer. The GaN transistor includes two or more gate electrodes between a drain electrode and a source electrode. A polarization layer is located between the first gate electrode and the second gate electrode, the polarization layer forming a two dimensional electron gas (2DEG) within the GaN layer, the 2DEG electrically coupling the first gate electrode and the second gate electrode.

Abstract: A method of fabricating a wafer is disclosed. The method includes forming a protective layer on a device side and a non-device side of a substrate of the wafer. The method further includes removing the protective layer from a center portion of the device side of the substrate while retaining the protective layer in an edge portion of the substrate. The method also includes forming semiconductor layer in the center portion of the device side of the substrate while the protective layer is in the edge portion of the substrate.

Abstract: Embodiments of the present disclosure are directed toward an integrated circuit (IC) die. In embodiments, an IC die may include a semiconductor substrate and a buffer layer disposed over the semiconductor substrate. The buffer layer may have a plurality of openings formed therein. In embodiments, the IC die may further include a plurality of group III-Nitride structures. Individual group III-Nitride structures of the plurality of group III-Nitride structures may include a lower portion disposed in a respective opening of the plurality of openings and an upper portion disposed over the respective opening. In embodiments, the upper portion may include a base extending radially from sidewalls of the respective opening over a surface of the buffer layer to form a perimeter around the respective opening. Other embodiments may be described and/or claimed.

Abstract: A gallium nitride transistor can include a silicon substrate and a first oxide layer and a second oxide layer on the substrate. A first gallium nitride layer may reside on the silicon substrate and the first and second oxide layers. A polarization layer may reside on the first gallium nitride layer. A two dimensional electron gas may exist in the first gallium nitride layer proximate to the polarization layer. A second gallium nitride layer may reside on a first sidewall of the polarization layer and on the first oxide layer on the substrate. A first p-doped gallium nitride layer may reside on the second gallium nitride layer. A third gallium nitride layer may reside on a second sidewall of the polarization layer and on the second oxide layer on the substrate. A second p-doped gallium nitride layer may reside on the second gallium nitride layer.

Abstract: Techniques are disclosed for forming transistors including retracted raised source/drain (S/D) to reduce parasitic capacitance. In some cases, the techniques include forming ledges for S/D epitaxial regrowth on a high-quality crystal nucleation surface. The techniques may also include forming the raised sections of the S/D regions (e.g., the portions adjacent to spacer material between the S/D regions and the gate material) in a manner such that the S/D raised sections are retracted from the gate material. This can be achieved by forming a notch at the interface between a polarization charge inducing layer and an oxide layer using a wet etch process, such that a relatively high-quality surface of the polarization charge inducing layer material is exposed for S/D regrowth. Therefore, the benefits derived from growing the S/D material from a high-quality nucleation surface can be retained while reducing the parasitic overlap capacitance penalty that would otherwise be present.

Abstract: Techniques are disclosed herein for ferroelectric-based field-effect transistors (FETs) with threshold voltage (VT) switching for enhanced RF switch transistor on-state and off-state performance. Employing a ferroelectric gate dielectric layer that can switch between two ferroelectric states enables a higher VT during the transistor off-state (VT,hi) and a lower VT during the transistor on-state (VT,lo). Accordingly, the transistor on-state resistance (Ron) can be maintained low due to the available relatively high gate overdrive (Vg,on?VT,lo) while still handling a relatively high maximum RF power in the transistor off-state due to the high VT,hi?Vg,off value. Thus, the Ron of an RF switch transistor can be improved without sacrificing maximum RF power, and/or vice versa, the maximum RF power can be improved without sacrificing the Ron. A ferroelectric layer (e.g., including HfxZryO) can be formed between a transistor gate dielectric layer and gate electrode to achieve such benefits.

Abstract: Semiconductor devices including an elevated or raised doped crystalline structure extending from a device layer are described. In embodiments, III-N transistors include raised crystalline n+ doped source/drain structures on either side of a gate stack. In embodiments, an amorphous material is employed to limit growth of polycrystalline source/drain material, allowing a high quality source/drain doped crystal to grow from an undamaged region and laterally expand to form a low resistance interface with a two-degree electron gas (2DEG) formed within the device layer. In some embodiments, regions of damaged GaN that may spawn competitive polycrystalline overgrowths are covered with the amorphous material prior to commencing raised source/drain growth.

Abstract: This disclosure is directed to a complementary metal oxide semiconductor (CMOS) transistor that includes a gallium nitride n-type MOS and a silicon P-type MOS. The transistor includes silicon 111 substrate, a gallium nitride transistor formed in a trench in the silicon 111 substrate, the gallium nitride transistor comprising a source electrode, a gate electrode, and a drain electrode; a polysilicon layer formed on the gallium nitride transistor, the polysilicon layer coplanar with a top side of the silicon 111 substrate; a first metal via disposed on the source electrode; a second metal via disposed on the gate electrode and isolated from the first metal via by a polysilicon layer; a first trench contact formed on the first metal via; and a second trench contact formed on the second metal via; the first trench contact isolated from the second trench contact by at least one replacement metal gate (RMG) polysilicon island.

Abstract: This disclosure pertains to a gallium nitride transistor that is formed in a trench etched into a silicon substrate. A gallium nitride layer is on the trench of the silicon substrate. A source electrode and a drain electrode reside on the gallium nitride layer. A gate electrode resides on the gallium nitride layer between the source electrode and the drain electrode. A first polarization layer resides on the gallium nitride layer between the source electrode and the gate electrode, and a second polarization layer resides on the gallium nitride layer between the gate electrode and the drain electrode. The silicon substrate can include a silicon 111 substrate.

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 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 devices integrating circuitry including both III-N (e.g., GaN) transistors and Si-based (e.g., Si or SiGe) transistors. In some monolithic wafer-level integration embodiments, a silicon-on-insulator (SOI) substrate is employed as an epitaxial platform providing a first silicon surface advantageous for seeding an epitaxial III-N semiconductor stack upon which III-N transistors (e.g., III-N HFETs) are formed, and a second silicon surface advantageous for seeding an epitaxial raised silicon upon which Si-based transistors (e.g., Si FETs) are formed. In some heterogeneous wafer-level integration embodiments, an SOI substrate is employed for a layer transfer of silicon suitable for fabricating the Si-based transistors onto another substrate upon which III-N transistors have been formed. In some such embodiments, the silicon layer transfer is stacked upon a planar interlayer dielectric (ILD) disposed over one or more metallization level interconnecting a plurality of III-N HFETs into HFET circuitry.