Abstract: Techniques are disclosed for forming transistors employing non-selective deposition of source and drain (S/D) material. Non-selectively depositing S/D material provides a multitude of benefits over only selectively depositing the S/D material, such as being able to attain relatively higher dopant activation, steeper dopant profiles, and better channel strain, for example.

Abstract: Techniques are disclosed for forming transistor structures including tensile-strained germanium (Ge) channel material. The transistor structures may be used for either or both of n-type and p-type transistor devices, as tensile-strained Ge has very high carrier mobility properties suitable for both types. Thus, a simplified CMOS integration scheme may be achieved by forming n-MOS and p-MOS devices included in the CMOS device using the techniques described herein. In some cases, the tensile-strained Ge may be achieved by epitaxially growing the Ge material on a group III-V material having a lattice constant that is higher than that of Ge and/or by applying a macroscopic 3-point bending to the die on which the transistor is formed. The techniques may be used to form transistors having planar or non-planar configurations, such as finned configurations (e.g., finFET or tri-gate) or gate-all-around (GAA) configurations (including at least one nanowire).

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 employing a carbon-based etch stop layer (ESL) for preserving source and drain (S/D) material during contact trench etch processing. As can be understood based on this disclosure, carbon-based layers can provide increased resistance for etch processing, such that employing a carbon-based ESL on S/D material can preserve that S/D material during contact trench etch processing. This is due to carbon-based layers being able to provide more robust (e.g., more selective) etch selectivity during contact trench etch processing than the S/D material it is preserving (e.g., Si, SiGe, Ge, group III-V semiconductor material) and other etch stop layers (e.g., insulator material-based etch stop layers). Employing a carbon-based ESL enables a given S/D region to protrude from shallow trench isolation (STI) material prior to contact metal deposition, thereby providing more surface area for making contact to the given S/D region, which improves transistor performance.

Abstract: Techniques are disclosed for forming transistors on the same substrate with varied channel materials. The techniques include forming a replacement material region in the substrate, such region used to form a plurality of fins therefrom, the fins used to form transistor channel regions. In an example case, the substrate may comprise Si and the replacement materials may include Ge, SiGe, and/or at least one III-V material. The replacement material regions can have a width sufficient to ensure a substantially planar interface between the replacement material and the substrate material. Therefore, the fins formed from the replacement material regions can also have a substantially planar interface between the replacement material and the substrate material. One example benefit from being able to form replacement material channel regions with such substantially planar interfaces can include at least a 30 percent improvement in current flow at a fixed voltage.

Abstract: An embodiment includes an apparatus comprising: a fin structure on a substrate, the fin structure including fin top and bottom portions, a channel including a majority carrier, and an epitaxial (EPI) layer; an insulation layer including insulation layer top and bottom portions adjacent the fin top and bottom portions; wherein (a) the EPI layer comprises one or more of group IV and lll-V materials, (b) the fin bottom portion includes a fin bottom portion concentration of dopants of opposite polarity to the majority carrier, (c) the fin top portion includes a fin top portion concentration of the dopants less than the fin bottom portion concentration, (d) the insulation layer bottom portion includes an insulation layer bottom portion concentration of the dopants, and (e) the insulation layer top portion includes an insulation top layer portion concentration greater than the insulation bottom portion concentration. Other embodiments are described herein.

Abstract: Techniques are disclosed for customization of fin-based transistor devices to provide a diverse range of channel configurations and/or material systems, and within the same integrated circuit die. In accordance with an embodiment, sacrificial fins are cladded and then removed thereby leaving the cladding layer as a pair of standalone fins. Once the sacrificial fin areas are filled back in with a suitable insulator, the resulting structure is fin-on-insulator. The new fins can be configured with any materials by using such a cladding-on-core approach. The resulting fin-on-insulator structure is favorable, for instance, for good gate control while eliminating or otherwise reducing sub-channel source-to-drain (or drain-to-source) leakage current. In addition, parasitic capacitance from channel-to-substrate is significantly reduced.

Abstract: Techniques are disclosed for backside source/drain (S/D) replacement for semiconductor devices with metallization on both sides (MOBS). The techniques described herein provide methods to recover or otherwise facilitate low contact resistance, thereby reducing or eliminating parasitic external resistance that degrades transistor performance. In some cases, the techniques include forming sacrificial S/D material and a seed layer during frontside processing of a device layer including one or more transistor devices. The device layer can then be inverted and bonded to a host wafer. A backside reveal of the device layer can then be performed via grinding, etching, and/or CMP processes. The sacrificial S/D material can then be removed through backside S/D contact trenches using the seed layer as an etch stop, followed by the formation of relatively highly doped final S/D material grown from the seed layer, to provide enhanced ohmic contact properties. Other embodiments may be described and/or disclosed.

Abstract: Techniques are disclosed for forming nanowire transistors employing carbon-based layers. Carbon is added to the sacrificial layers and/or non-sacrificial layers of a multilayer stack forming one or more nanowires in the transistor channel region. Such carbon-based layers reduce or prevent diffusion and intermixing of the sacrificial and non-sacrificial portions of the multilayer stack. The reduction of diffusion/intermixing can allow for the originally formed layers to effectively maintain their original thicknesses, thereby enabling the formation of relatively more nanowires for a given channel region height because of the more accurate processing scheme. The techniques can be used to benefit group IV semiconductor material nanowire devices (e.g., devices including Si, Ge, and/or SiGe) and can also assist with the selective etch processing used to form the nanowires.

Abstract: Integrated circuit transistor structures are disclosed that include a single crystal buffer structure that is lattice matched to the underlying single crystal silicon substrate. The buffer structure may be used to reduce sub-fin leakage in non-planar transistors, but can also be used in planar configurations. In some embodiments, the buffer structure is a single continuous layer of high bandgap dielectric material that is lattice matched to silicon. The techniques below can be utilized on NMOS and PMOS transistors, including any number of group IV and III-V semiconductor channel materials.

Abstract: Techniques are disclosed for forming increasing channel region tensile strain in n-MOS devices. In some cases, increased channel region tensile strain can be achieved via S/D material engineering that deliberately introduces dislocations in one or both of the S/D regions to produce tensile strain in the adjacent channel region. In some such cases, the S/D material engineering to create desired dislocations may include using a lattice mismatched epitaxial S/D film adjacent to the channel region. Numerous material schemes for achieving multiple dislocations in one or both S/D regions will be apparent in light of this disclosure. In some cases, a cap layer can be formed on an S/D region to reduce contact resistance, such that the cap layer is an intervening layer between the S/D region and S/D contact. The cap layer includes different material than the underlying S/D region and/or a higher dopant concentration to reduce contact resistance.

Abstract: Integrated circuit transistor structures are disclosed that include a gate structure that is lattice matched to the underlying channel. In particular, the gate dielectric is lattice matched to the underlying semiconductor channel material, and in some embodiments, so is the gate electrode. In an example embodiment, single crystal semiconductor channel material and single crystal gate dielectric material that are sufficiently lattice matched to each other are epitaxially deposited. In some cases, the gate electrode material may also be a single crystal material that is lattice matched to the semiconductor channel material, thereby allowing the gate electrode to impart strain on the channel via the also lattice matched gate dielectric. A gate dielectric material that is lattice matched to the channel material can be used to reduce interface trap density (Dit). The techniques can be used in both planar and non-planar (e.g., finFET and nanowire) metal oxide semiconductor (MOS) transistor architectures.

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 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: A replacement fin layer is deposited on a sub-fin layer in trenches isolated by an insulating layer on a substrate. The replacement fin layer has first component rich side portions and a second component rich core portion. The second component rich core portion is etched to generate a double fin structure comprising the first component rich fins.

Abstract: A trench is formed in an insulating layer to expose a native fin on a substrate. A replacement fin is deposited on the native fin in the trench. The replacement fin is trimmed laterally.

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 forming transistor structures including tensile-strained germanium (Ge) channel material. The transistor structures may be used for either or both of n-type and p-type transistor devices, as tensile-strained Ge has very high carrier mobility properties suitable for both types. Thus, a simplified CMOS integration scheme may be achieved by forming n-MOS and p-MOS devices included in the CMOS device using the techniques described herein. In some cases, the tensile-strained Ge may be achieved by epitaxially growing the Ge material on a group III-V material having a lattice constant that is higher than that of Ge and/or by applying a macroscopic 3-point bending to the die on which the transistor is formed. The techniques may be used to form transistors having planar or non-planar configurations, such as finned configurations (e.g., finFET or tri-gate) or gate-all-around (GAA) configurations (including at least one nanowire).

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: 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.