Abstract:
Techniques are disclosed for providing a low resistance self-aligned contacts to devices formed in a semiconductor heterostructure. The techniques can be used, for example, for forming contacts to the gate, source and drain regions of a quantum well transistor fabricated in III-V and SiGe/Ge material systems. Unlike conventional contact process flows which result in a relatively large space between the source/drain contacts to gate, the resulting source and drain contacts provided by the techniques described herein are self-aligned, in that each contact is aligned to the gate electrode and isolated therefrom via spacer material.
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 III-N semiconductor channel is formed on a III-N transition layer formed on a (111) or (110) surface of a silicon template structure, such as a fin sidewall. In embodiments, the silicon fin has a width comparable to the III-N epitaxial film thicknesses for a more compliant seeding layer, permitting lower defect density and/or reduced epitaxial film thickness. In embodiments, a transition layer is GaN and the semiconductor channel comprises Indium (In) to increase a conduction band offset from the silicon fin. In other embodiments, the fin is sacrificial and either removed or oxidized, or otherwise converted into a dielectric structure during transistor fabrication. In certain embodiments employing a sacrificial fin, the III-N transition layer and semiconductor channel is substantially pure GaN, permitting a breakdown voltage higher than would be sustainable in the presence of the silicon fin.
Abstract:
Non-planar semiconductor devices having group III-V material active regions with multi-dielectric gate stacks are described. For example, a semiconductor device includes a hetero-structure disposed above a substrate. The hetero-structure includes a three-dimensional group III-V material body with a channel region. A source and drain material region is disposed above the three-dimensional group III-V material body. A trench is disposed in the source and drain material region separating a source region from a drain region, and exposing at least a portion of the channel region. A gate stack is disposed in the trench and on the exposed portion of the channel region. The gate stack includes first and second dielectric layers and a gate electrode.
Abstract:
A III-N semiconductor channel is formed on a III-N transition layer formed on a (111) or (110) surface of a silicon template structure, such as a fin sidewall. In embodiments, the silicon fin has a width comparable to the III-N epitaxial film thicknesses for a more compliant seeding layer, permitting lower defect density and/or reduced epitaxial film thickness. In embodiments, a transition layer is GaN and the semiconductor channel comprises Indium (In) to increase a conduction band offset from the silicon fin. In other embodiments, the fin is sacrificial and either removed or oxidized, or otherwise converted into a dielectric structure during transistor fabrication. In certain embodiments employing a sacrificial fin, the III-N transition layer and semiconductor channel is substantially pure GaN, permitting a breakdown voltage higher than would be sustainable in the presence of the silicon fin.
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:
An embodiment concerns forming an EPI film on a substrate where the EPI film has a different lattice constant from the substrate. The EPI film and substrate may include different materials to collectively form a hetero-epitaxial device having, for example, a Si and/or SiGe substrate and a III-V or IV film. The EPI film may be one of multiple EPI layers or films and the films may include different materials from one another and may directly contact one another. Further, the multiple EPI layers may be doped differently from another in terms of doping concentration and/or doping polarity. One embodiment includes creating a horizontally oriented hetero-epitaxial structure. Another embodiment includes a vertically oriented hetero-epitaxial structure. The hetero-epitaxial structures may include, for example, a bipolar junction transistor, heterojunction bipolar transistor, thyristor, and tunneling field effect transistor among others. Other embodiments are described herein.
Abstract:
An embodiment includes depositing a material onto a substrate where the material includes a different lattice constant than the substrate (e.g., III-V or IV epitaxial (EPI) material on a Si substrate). An embodiment includes an EPI layer formed within a trench having walls that narrow as the trench extends upwards. An embodiment includes an EPI layer formed within a trench using multiple growth temperatures. A defect barrier, formed in the EPI layer when the temperature changes, contains defects within the trench and below the defect barrier. The EPI layer above the defect barrier and within the trench is relatively defect free. An embodiment includes an EPI layer annealed within a trench to induce defect annihilation. An embodiment includes an EPI superlattice formed within a trench and covered with a relatively defect free EPI layer (that is still included in the trench). Other embodiments are described herein.
Abstract:
III-N semiconductor-on-silicon integrated circuit structures and techniques are disclosed. In some cases, the structure includes a first semiconductor layer formed on a nucleation layer, the first semiconductor layer including a 3-D GaN layer on the nucleation layer and having a plurality of 3-D semiconductor structures, and a 2-D GaN layer on the 3-D GaN layer. The structure also may include a second semiconductor layer formed on or within the first semiconductor layer, wherein the second semiconductor layer includes AlGaN on the 2-D GaN layer and a GaN layer on the AlGaN layer. Another structure includes a first semiconductor layer formed on a nucleation layer, the first semiconductor layer comprising a 2-D GaN layer on the nucleation layer, and a second semiconductor layer formed on or within the first semiconductor layer, wherein the second semiconductor layer includes AlGaN on the 2-D GaN layer and a GaN layer on the AlGaN layer.
Abstract:
Described herein are techniques related to implementation of a quantum key distribution (QKD) scheme by a photonic integrated circuit (PIC). For example, the PIC is a component in a wireless device that is used for quantum communications in a quantum communications system.