Abstract: Techniques are disclosed for controlling transistor sub-fin leakage. The techniques can be used for highly scaled finFETs, as well as other non-planar transistors. In some cases, the techniques include exposing a middle portion of a fin structure formed on a substrate and then converting the exposed portion to an electrically isolating material via a doping or oxidation process. For example, a monolayer doping (MLD) process may be used to deliver dopants to the exposed portion of the fin in a self-saturated monolayer scheme. In another example case, thermal oxidation may be used to convert the exposed portion to an insulator material. In some cases, a barrier layer (e.g., including carbon doping) may be located above the exposed portion of the fin to help prevent the doping or oxidation process from affecting the upper region of the fin, which is used for the transistor channel.

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 STI is doped with an n-type impurity, in regions of the STI adjacent to the source and/or drain regions, to provide dopant diffusion reduction. In some embodiments, the STI region is doped with an n-type impurity including Phosphorous in a concentration between 1 and 10% by atomic percentage. In some embodiments, the thickness of the doped STI region may range between 10 and 100 nanometers.

Abstract: Techniques for forming contacts comprising at least one crystal on source and drain (S/D) regions of semiconductor devices are described. Crystalline S/D contacts can be formed so as to conform to some or all of the top and side surfaces of the S/D regions. Crystalline S/D contacts of the present disclosure are formed by selectively depositing precursor on an exposed portion of one or more S/D regions. The precursor are then reacted in situ on the exposed portion of the S/D region. This reaction forms the conductive, crystalline S/D contact that conforms to the surface of the S/D regions.

Abstract: Particular embodiments described herein provide for an electronic device that can include a nanowire channel. The nanowire channel can include nanowires and the nanowires can be about fifteen (15) or less angstroms apart. The nanowire channel can include more than ten (10) nanowires and can be created from a MXene material.

Abstract: Embodiments herein describe techniques, systems, and method for a semiconductor device. A nanowire transistor may include a channel region including a nanowire above a substrate, a source electrode coupled to a first end of the nanowire through a first etch stop layer, and a drain electrode coupled to a second end of the nanowire through a second etch stop layer. A gate electrode may be above the substrate to control conductivity in at least a portion of the channel region. A first spacer may be above the substrate between the gate electrode and the source electrode, and a second spacer may be above the substrate between the gate electrode and the drain electrode. A gate dielectric layer may be between the channel region and the gate electrode. Other embodiments may be described and/or claimed.

Abstract: Techniques are disclosed for forming germanium (Ge)-rich channel transistors including one or more dopant diffusion barrier elements. The introduction of one or more dopant diffusion elements into at least a portion of a given source/drain (S/D) region helps inhibit the undesired diffusion of dopant (e.g., B, P, or As) into the adjacent Ge-rich channel region. In some embodiments, the elements that may be included in a given S/D region to help prevent the undesired dopant diffusion include at least one of tin and relatively high silicon. Further, in some such embodiments, carbon may also be included to help prevent the undesired dopant diffusion. In some embodiments, the one or more dopant diffusion barrier elements may be included in an interfacial layer between a given S/D region and the Ge-rich channel region and/or throughout at least a majority of a given S/D region. Numerous embodiments, configurations, and variations will be apparent.

Abstract: Techniques are disclosed for forming transistors including one or more group III-V semiconductor material nanowires using sacrificial group IV semiconductor material layers. In some cases, the transistors may include a gate-all-around (GAA) configuration. In some cases, the techniques may include forming a replacement fin stack that includes group III-V material layer (such as indium gallium arsenide, indium arsenide, or indium antimonide) formed on a group IV material buffer layer (such as silicon, germanium, or silicon germanium), such that the group IV buffer layer can be later removed using a selective etch process to leave the group III-V material for use as a nanowire in a transistor channel. In some such cases, the group III-V material layer may be grown pseudomorphically to the underlying group IV material, so as to not form misfit dislocations. The techniques may be used to form transistors including any number of nanowires.

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: Techniques are disclosed for backside contact resistance reduction for semiconductor devices with metallization on both sides (MOBS). In some embodiments, the techniques described herein provide methods to recover low contact resistance that would otherwise be present with making backside contacts, thereby reducing or eliminating parasitic external resistance that degrades transistor performance. In some embodiments, the techniques include adding an epitaxial deposition of very highly doped crystalline semiconductor material in backside contact trenches to provide enhanced ohmic contact properties. In some cases, a backside source/drain (S/D) etch-stop layer may be formed below the replacement S/D regions of the one or more transistors formed on the transfer wafer (during frontside processing), such that when backside contact trenches are being formed, the backside S/D etch-stop layer may help stop the backside contact etch process before consuming a portion or all of the S/D material.

Abstract: Techniques and mechanisms for imposing stress on a channel region of an NMOS transistor. In an embodiment, a fin structure on a semiconductor substrate includes two source or drain regions of the transistor, wherein a channel region of the transistor is located between the source or drain regions. At least on such source or drain region includes a doped silicon germanium (SiGe) compound, wherein dislocations in the SiGe compound result in the at least one source or drain region exerting a tensile stress on the channel region. In another embodiment, source or drain regions of a transistor each include a SiGe compound which comprises at least 50 wt % germanium.

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: Techniques are described for forming strained fins for co-integrated n-MOS and p-MOS devices that include one or more defect trapping layers that prevent defects from migrating into channel regions of the various co-integrated n-MOS and p-MOS devices. A defect trapping layer can include one or more patterned dielectric layers that define aspect ratio trapping trenches. An alternative defect trapping layer can include a superlattice structure of alternating, epitaxially mismatched materials that provides an energetic barrier to the migration of defect. Regardless, the defect trapping layer can prevent dislocations, stacking faults, and other crystallographic defects present in a relaxed silicon germanium layer from migrating into strained n-MOS and p-MOS channel regions grown thereon.

Abstract: Techniques are disclosed for forming germanium (Ge)-rich channel transistors including one or more dopant diffusion barrier elements. The introduction of one or more dopant diffusion elements into at least a portion of a given source/drain (S/D) region helps inhibit the undesired diffusion of dopant (e.g., B, P, or As) into the adjacent Ge-rich channel region. In some embodiments, the elements that may be included in a given S/D region to help prevent the undesired dopant diffusion include at least one of tin and relatively high silicon. Further, in some such embodiments, carbon may also be included to help prevent the undesired dopant diffusion. In some embodiments, the one or more dopant diffusion barrier elements may be included in an interfacial layer between a given S/D region and the Ge-rich channel region and/or throughout at least a majority of a given S/D region. Numerous embodiments, configurations, and variations will be apparent.

Abstract: Methods of forming germanium channel structure are described. An embodiment includes forming a germanium fin on a substrate, wherein a portion of the germanium fin comprises a germanium channel region, forming a gate material on the germanium channel region, and forming a graded source/drain structure adjacent the germanium channel region. The graded source/drain structure comprises a germanium concentration that is higher adjacent the germanium channel region than at a source/drain contact region.

Abstract: Methods of forming self-aligned nanowire spacer structures are described. An embodiment includes forming a channel structure comprising a first nanowire and a second nanowire. Source/drain structures are formed adjacent the channel structure, wherein a liner material is disposed on at least a portion of the sidewalls of the source/drain structures. A nanowire spacer structure is formed between the first and second nanowires, wherein the nanowire spacer comprises an oxidized portion of the liner.

Abstract: An apparatus is provided which comprises: a semiconductor region on a substrate, a gate stack on the semiconductor region, a source region comprising doped semiconductor material on the substrate adjacent a first side of the semiconductor region, a drain region comprising doped semiconductor material on the substrate adjacent a second side of the semiconductor region, a substantially conformal semiconductor layer over a surface of a recess in the source region, and a metal over the conformal layer substantially filling the recess in the source region. Other embodiments are also disclosed and claimed.

Abstract: Methods of forming germanium channel structure are described. An embodiment includes forming a germanium fin on a substrate, wherein a portion of the germanium fin comprises a germanium channel region, forming a gate material on the germanium channel region, and forming a graded source/drain structure adjacent the germanium channel region. The graded source/drain structure comprises a germanium concentration that is higher adjacent the germanium channel region than at a source/drain contact region.

Abstract: Tensile strain is applied to a channel region of a transistor by depositing an amorphous SixGe1-x-yCy alloy in at least one of a source and a drain (S/D) region of the transistors. The amorphous SixGe1-x-yCy alloy is crystallized, thus reducing the unit volume of the alloy. This volume reduction in at least one of the source and the drain region applies strain to a connected channel region. This strain improves electron mobility in the channel. Dopant activation in the source and drain locations is recovered during conversion from amorphous to crystalline structure. Presence of high carbon concentrations reduces dopant diffusion from the source and drain locations into the channel region. The techniques may be employed with respect to both planar and non-planar (e.g., FinFET and nanowire) transistors.

Abstract: Techniques are disclosed for fabricating semiconductor transistor devices configured with a sub-fin insulation layer that reduces parasitic leakage (i.e., current leakage through a portion of an underlying substrate between a source region and a drain region associated with a transistor). The parasitic leakage is reduced by fabricating transistors with a sacrificial layer in a sub-fin region of the substrate below at least a channel region of the fin. During processing, the sacrificial layer in the sub-fin region is removed and replaced, either in whole or in part, with a dielectric material. The dielectric material increases the electrical resistivity of the substrate between corresponding source and drain portions of the fin, thus reducing parasitic leakage.

Abstract: Techniques are disclosed for reducing off-state leakage of fin-based transistors through the use of a sub-fin passivation layer. In some cases, the techniques include forming sacrificial fins in a bulk silicon substrate and depositing and planarizing shallow trench isolation (STI) material, removing and replacing the sacrificial silicon fins with a replacement material (e.g., SiGe or III-V material), removing at least a portion of the STI material to expose the sub-fin areas of the replacement fins, applying a passivating layer/treatment/agent to the exposed sub-fins, and re-depositing and planarizing additional STI material. Standard transistor forming processes can then be carried out to complete the transistor device. The techniques generally provide the ability to add arbitrary passivation layers for structures that are grown in STI-based trenches. The passivation layer inhibits sub-fin source-to-drain (and drain-to-source) current leakage.