Abstract: Stacked transistor structures having a conductive interconnect between source/drain regions of upper and lower transistors. In some embodiments, the interconnect is provided, at least in part, by highly doped epitaxial material deposited in the upper transistor’s source/drain region. In such cases, the epitaxial material seeds off of an exposed portion of semiconductor material of or adjacent to the upper transistor’s channel region and extends downward into a recess that exposes the lower transistor’s source/drain contact structure. The epitaxial source/drain material directly contacts the lower transistor’s source/drain contact structure, to provide the interconnect. In other embodiments, the epitaxial material still seeds off the exposed semiconductor material of or proximate to the channel region and extends downward into the recess, but need not contact the lower contact structure.

Abstract: Integrated circuit structures having source or drain structures with abrupt dopant profiles are described. In an example, an integrated circuit structure includes a vertical arrangement of horizontal nanowires. A gate stack is around the vertical arrangement of horizontal nanowires. A first epitaxial source or drain structure is at a first end of the vertical arrangement of horizontal nanowires. A second epitaxial source or drain structure is at a second end of the vertical arrangement of horizontal nanowires. The first and second epitaxial source or drain structures include silicon, phosphorous and arsenic, with an atomic concentration of phosphorous substantially the same as an atomic concentration of arsenic.

Abstract: Disclosed herein are tri-gate transistor arrangements, and related methods and devices. For example, in some embodiments, a transistor arrangement may include a fin stack shaped as a fin extending away from a base, and a subfin dielectric stack. The fin includes a subfin portion and a channel portion, the subfin portion being closer to the base than the channel portion. The subfin dielectric stack includes a transistor dielectric material, and a fixed charge liner material disposed between the transistor dielectric material and the subfin portion of the fin.

Abstract: Embodiments of the disclosure are in the field of advanced integrated circuit structure fabrication and, in particular, integrated circuit structures having source or drain structures with selective silicide contacts thereon are described. In an example, an integrated circuit structure includes a plurality of stacks of nanowires. A plurality of epitaxial source or drain structures is around ends of corresponding ones of the stacks of nanowires. A silicide layer is on an entirety of a top surface of the plurality of epitaxial source or drain structures. A conductive trench contact is on the silicide layer. A dielectric layer is vertically intervening between a portion of the conductive trench contact and the silicide layer.

Abstract: Disclosed herein are transistor gate-channel arrangements with transistor gate stacks that include thick hysteretic elements (i.e., hysteretic elements having a thickness of at least 10-15 nanometers, e.g., between 55 and 100 nanometers), and related methods and devices. Transistor gate stacks disclosed herein include a multilayer gate insulator having a thick hysteretic element and an interface layer, where the thick hysteretic element is between the interface layer and a gate electrode material, and the interface layer is between the thick hysteretic element and a channel material of a transistor. The interface layer may be a dielectric material with an effective dielectric constant of at least 20 and/or be a dielectric material that is thinner than about 3 nanometers. Such an interface layer may help improve gate control and allow use of thick hysteretic elements while maintaining transistor performance in terms of, e.g., gate leakage, carrier mobility, and subthreshold swing.

Abstract: An apparatus including a transistor device disposed on a surface of a circuit substrate, the device including a body including opposing sidewalls defining a width dimension and a channel material including indium, the channel material including a profile at a base thereof that promotes indium atom diffusivity changes in the channel material in a direction away from the sidewalls. A method including forming a transistor device body on a circuit substrate, the transistor device body including opposing sidewalls and including a buffer material and a channel material on the buffer material, the channel material including indium and the buffer material includes a facet that promotes indium atom diffusivity changes in the channel material in a direction away from the sidewalls; and forming a gate stack on the channel material.

Abstract: The scaling of features in ICs has been a driving force behind an ever-growing semiconductor industry. As transistors of the ICs become smaller, their gate lengths become smaller, leading to undesirable short-channel effects such as poor leakage, poor subthreshold swing, drain-induced barrier lowering, etc. Reducing transistor dimensions at the gate allows keeping the footprint of the transistor relatively small and comparable to what could be achieved implementing a transistor with a shorter gate length while effectively increasing transistor's effective gate length and thus reducing the negative impacts of short-channel effects. This architecture may be optimized even further if transistors are to be operated at relatively low temperatures, e.g., below 200 Kelvin degrees or lower.

Abstract: Techniques are disclosed for forming transistors including source and drain (S/D) regions employing double-charge dopants. As can be understood based on this disclosure, the use of double-charge dopants for group IV semiconductor material (e.g., Si, Ge, SiGe) either alone or in combination with single-charge dopants (e.g., P, As, B) can decrease the energy barrier at the semiconductor/metal interface between the source and drain regions (semiconductor) and their respective contacts (metal), thereby improving (by reducing) contact resistance at the S/D locations. In some cases, the double-charge dopants may be provided in a top or cap S/D portion of a given S/D region, for example, so that the double-charge doped S/D material is located at the interface of that S/D region and the corresponding contact. The double-charge dopants can include sulfur (S), selenium (Se), and/or tellurium (Te). Other suitable group IV material double-charge dopants will be apparent in light of this disclosure.

Abstract: Epitaxial oxide plugs are described for imposing strain on a channel region of a proximate channel region of a transistor. The oxide plugs form epitaxial and coherent contact with one or more source and drain regions adjacent to the strained channel region. The epitaxial oxide plugs can be used to either impart strain to an otherwise unstrained channel region (e.g., for a semiconductor body that is unstrained relative to an underlying buffer layer), or to restore, maintain, or increase strain within a channel region of a previously strained semiconductor body. The epitaxial crystalline oxide plugs have a perovskite crystal structure in some embodiments.

Abstract: Memory devices including vertical transistors and methods of forming such memory devices are disclosed. An example memory device includes a substrate, a BL in the substrate, a channel region over a portion of the BL, a second region over the channel region, an insulator wrapped around at least a portion of the channel region, and a WL. The BL also operates as one of a source region and a drain region of the transistor. The second region is the other one of the source region and the drain region. The WL wraps around at least a portion of the insulator and is separated from the channel region by the insulator. In some embodiments, the BL is formed in a trench in the substrate. An aspect ratio of the BL is in a range from 0.5 to 10. The BL may have a higher conductivity than the channel region.

Abstract: Fin smoothing, and integrated circuit structures resulting therefrom, are described. For example, an integrated circuit structure includes a semiconductor fin having a protruding fin portion above an isolation structure, the protruding fin portion having substantially vertical sidewalls. The semiconductor fin further includes a sub-fin portion within an opening in the isolation structure, the sub-fin portion having a different semiconductor material than the protruding fin portion. The sub-fin portion has a width greater than or less than a width of the protruding portion where the sub-fin portion meets the protruding portion. A gate stack is over and conformal with the protruding fin portion of the semiconductor fin. A first source or drain region at a first side of the gate stack, and a second source or drain region at a second side of the gate stack opposite the first side of the gate stack.

Abstract: Hybrid FETs and methods of forming such hybrid FETs are disclosed. An example hybrid FET includes a channel region, a first region, a second region, a third region, and two gates. A gate may wrap around a portion of the channel region. The channel region may be over a first substrate (e.g., a substrate on which the channel region is formed) but cross a second substrate. The channel region is shared by a MOSFET and a TFET. The first region and second region constitute the source and drain of the MOSFET and are doped with dopants of the same type. The first region and third region constitute the source and drain of the TFET and are doped with dopants of opposite types. The third region may be placed at the opposite side of the second substrate from the first region and the second region.

Abstract: Described herein are memory devices that include a cooling structure for cooling one or more memory arrays. The memory arrays may be static random access memory (SRAM) arrays formed in multiple layers as a stacked memory device. The cooling structure may cool one or more layers of an SRAM device. For example, a cooling structure may be formed around the SRAM device and coupled to a cooling device. Alternatively, a cooling layer may be included in a memory device and coupled to one or more thermal interface layers in thermal contact with a memory layer by cold vias. The cold vias transfer a cold temperature from the cooling layer to the thermal interface layer to cool the thermal interface layer and, in turn, the memory arrays.

Abstract: Stacked transistor structures having a conductive interconnect between source/drain regions of upper and lower transistors. In some embodiments, the interconnect is provided, at least in part, by highly doped epitaxial material deposited in the upper transistor's source/drain region. In such cases, the epitaxial material seeds off of an exposed portion of semiconductor material of or adjacent to the upper transistor's channel region and extends downward into a recess that exposes the lower transistor's source/drain contact structure. The epitaxial source/drain material directly contacts the lower transistor's source/drain contact structure, to provide the interconnect. In other embodiments, the epitaxial material still seeds off the exposed semiconductor material of or proximate to the channel region and extends downward into the recess, but need not contact the lower contact structure.

Abstract: IC devices including angled transistors formed based on angled wafers are disclosed. An example IC device includes a substrate and a semiconductor structure. A crystal direction of a crystal structure in the semiconductor structure is not aligned with a corresponding crystal direction (e.g., having same Miller indices) of a crystal structure in the substrate. An angle between the two crystal directions may be 4-60 degrees. The semiconductor structure is formed based on another substrate (e.g., a wafer) that has a different orientation from the substrate, e.g., flats or notches of the two substrates are not aligned. The crystal direction of the semiconductor structure may be determined based on a crystal direction in the another substrate. The semiconductor structure may be a portion of a transistor, e.g., the channel region and S/D regions of the transistor. The semiconductor structure may be angled with respect to an edge of the substrate.

Abstract: IC devices including vertical TFETs are disclosed. An example IC device includes a substrate, a channel region, a first region, and a second region. One of the first and second regions is a source region and another one is a drain region. The first region includes a first semiconductor material. The second region includes a second semiconductor material that may be different from the first semiconductor material. The first region and the second region are doped with opposite types of dopants. The channel region includes a third semiconductor material that may be different from the first or second semiconductor material. The channel region is between the first region and the second region. The first region is between the channel region and the substrate. In some embodiments, the first or second region is formed through layer transfer or epitaxy (e.g., graphoepitaxy, chemical epitaxy, or a combination of both).

Abstract: The scaling of features in ICs has been a driving force behind an ever-growing semiconductor industry. As transistors of the ICs become smaller, their gate lengths become smaller, leading to undesirable short-channel effects such as poor leakage, poor subthreshold swing, drain-induced barrier lowering, etc. Embodiments of the present disclosure are based on recognition that extending at least one of two S/D contacts of a transistor into a channel layer while keeping it separated from a corresponding gate stack by a channel material may allow keeping the footprint of the transistor relatively small while effectively increasing transistor's effective gate length and thus reducing the negative impacts of short-channel effects. This architecture may be optimized even further if transistors are to be operated at relatively low temperatures, e.g., below 200 Kelvin degrees or lower. For multiple transistors, some of the S/D contacts may be shared to further increase transistor density.

Abstract: Integrated circuit transistor structures and processes are disclosed that reduce n-type dopant diffusion, such as phosphorous or arsenic, from the source region and the drain region of a germanium n-MOS device into adjacent channel regions during fabrication. The n-MOS transistor device may include at least 70% germanium (Ge) by atomic percentage. In an example embodiment, source and drain regions of the transistor are formed using a low temperature, non-selective deposition process of n-type doped material. In some embodiments, the low temperature deposition process is performed in the range of 450 to 600 degrees C. The resulting structure includes a layer of doped mono-crystyalline silicon (Si), or silicon germanium (SiGe), on the source/drain regions. The structure also includes a layer of doped amorphous Si:P (or SiGe:P) on the surfaces of a shallow trench isolation (STI) region and the surfaces of contact trench sidewalls.

Abstract: Disclosed herein are transistor gate-channel arrangements with transistor gate stacks that include dipole layers, and related methods and devices. Transistor gate stacks disclosed herein include a multilayer gate oxide having both a high-k dielectric and a dipole layer. In some embodiments, a thin dipole layer may directly border a channel material of choice and may be between the channel material and the high-k dielectric. In other embodiments, a passivation layer may spontaneously form between the dipole layer and the channel material. In still other embodiments, the high-k dielectric may be between the dipole layer and the channel material. Temporary polarization provided by the dipole layer may increase the effective dielectric constant of the high-k dielectric and may allow to use thinner high-k dielectrics and/or high-k dielectrics of suboptimal quality while maintaining transistor performance in terms of, e.g., gate leakage, carrier mobility, and subthreshold swing.

Abstract: Integrated circuit transistor structures are disclosed that reduce n-type dopant diffusion, such as phosphorous or arsenic, from the source region and the drain region of a germanium n-MOS device into adjacent shallow trench isolation (STI) regions during fabrication. The n-MOS transistor device may include at least 75% germanium by atomic percentage. In an example embodiment, the structure includes an intervening diffusion barrier deposited between the n-MOS transistor and the STI region to provide dopant diffusion reduction. In some embodiments, the diffusion barrier may include silicon dioxide with carbon concentrations between 5 and 50% by atomic percentage. In some embodiments, the diffusion barrier may be deposited using chemical vapor deposition (CVD), atomic layer deposition (ALD), or physical vapor deposition (PVD) techniques to achieve a diffusion barrier thickness in the range of 1 to 5 nanometers.