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:
Embodiments of semiconductor assemblies, and related integrated circuit devices and techniques, are disclosed herein. In some embodiments, a semiconductor assembly may include a flexible substrate, a polycrystalline semiconductor material, and a polycrystalline dielectric disposed between and adjacent to the flexible substrate and the polycrystalline semiconductor material. The polycrystalline semiconductor material may include a polycrystalline III-V material, a polycrystalline II-VI material or polycrystalline germanium. Other embodiments may be disclosed and/or claimed.
Abstract:
Techniques are disclosed for forming a GaN transistor on a semiconductor substrate. An insulating layer forms on top of a semiconductor substrate. A trench, filled with a trench material comprising a III-V semiconductor material, forms through the insulating layer and extends into the semiconductor substrate. A channel structure, containing III-V material having a defect density lower than the trench material, forms directly on top of the insulating layer and adjacent to the trench. A source and drain form on opposite sides of the channel structure, and a gate forms on the channel structure. The semiconductor substrate forms a plane upon which both GaN transistors and other transistors can form.
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:
Trench-confined selective epitaxial growth process in which epitaxial growth of a semiconductor device layer proceeds within the confines of a trench. In embodiments, a trench is fabricated to include a pristine, planar semiconductor seeding surface disposed at the bottom of the trench. Semiconductor regions around the seeding surface may be recessed relative to the seeding surface with Isolation dielectric disposed there on to surround the semiconductor seeding layer and form the trench. In embodiments to form the trench, a sacrificial hardmask fin may be covered in dielectric which is then planarized to expose the hardmask fin, which is then removed to expose the seeding surface. A semiconductor device layer is formed from the seeding surface through selective heteroepitaxy. In embodiments, non-planar devices are formed from the semiconductor device layer by recessing a top surface of the isolation dielectric. In embodiments, non-planar devices CMOS devices having high carrier mobility may be made from the semiconductor device layer.
Abstract:
A transistor (100) includes a first part of a gate (111) above a substrate (101) that has a first width and a second part of the gate above the first part of the gate that is centered with respect to the first part of the gate and that has a second width that is greater than the first width. The first part of the gate and the second part of the gate form a single monolithic T-gate structure.
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:
CMOS circuits may formed using p-channel gallium nitride transistors and n-channel gallium nitride transistors, wherein both the p-channel gallium nitride transistors and the n-channel gallium nitride transistors are formed on a single layered structure comprising a polarization layer deposited on a first gallium nitride layer and a second gallium nitride layer deposited on the polarization layer. Having both n-channel gallium nitride transistors and p-channel gallium nitride transistors s on the same layer structure may enable “all gallium nitride transistor” implementations of circuits including logic, digital, and analog circuitries spanning low supply voltages to high supply voltages.