Abstract: Semiconductor devices and systems with liner-last trench contacts, and methods of forming the same. The semiconductor device comprises a source region and a drain region, a source trench contact coupled to the source region, and a drain trench contact coupled to the drain region. Each trench contact resides in a contact trench and includes a contact plug, a contact metal layer below the contact plug, and a trench liner at the sidewalls of the contact trench. The uppermost surface of the contact metal layer is below the lowermost surface of the trench liner. A channel couples the source region to the drain region, and a gate couples to the channel. The trench liner includes silicon and at least one of oxygen and carbon. The device may correspond to a nanoribbon transistor, a gate-all-around (GAA) transistor, a fin field-effect transistor (FinFET), a planar transistor, or a two-dimensional transistor.

Abstract: Technologies for strain engineering in gate-all-around (GAA) field-effect transistors (FETs) are disclosed. In an illustrative embodiment, the source/drain contacts for N-type metal-oxide-semiconductor (NMOS) FETs extend deeper into the source/drain regions than the source/drain contacts for P-type metal-oxide-semiconductor (PMOS) FETs. The source/drain contacts for the NMOS FETs may cause a tensile strain in the channel of the NMOS FETs, while the source/drain region of the PMOS FETS may cause a compressive strain in the channel of the PMOS FETs. The tensile and compressive strains on the NMOS and PMOS channels, respectively, can increase the speed of the NMOS and PMOS transistors.

Abstract: Architectures and methods for differential CMOS contact profiles. Architectures include a CMOS isolation layer with a plurality of negative metal oxide semiconductor (NMOS) regions and a plurality of positive metal oxide semiconductor (PMOS) regions. The NMOS regions have a respective NMOS contact characterized by a first cavity formed in an upper surface of the isolation layer, extending orthogonally into the NMOS region to a first depth, and filled with a conductive material. The PMOS regions have a respective PMOS contact characterized by a second cavity formed in the upper surface of the isolation layer, extending orthogonally into the PMOS region to a second depth, and filled with the conductive material. The first depth is more than four times the second depth.

Abstract: Contacts to n-type source/drain regions comprise a phosphide or arsenide metal compound layer. The phosphide or arsenide metal compound layers can aid in forming thermally stable low resistance contacts. A phosphide or arsenide metal compound layer is positioned between the source/drain region and the contact metal layer of the contact. A phosphide or arsenic metal compound layer can be used in contacts contacting n-type source/drain regions comprising phosphorous or arsenic as the primary dopant, respectively. The phosphide or arsenide metal compound layers prevent diffusion of phosphorous or arsenic from the source/drain region into the metal contact layer and dopant deactivation in the source/drain region due to annealing and other high-temperature processing steps that occur after contact formation.

Abstract: Contact over active gate (COAG) structures with trench contact layers, and methods of fabricating contact over active gate (COAG) structures using trench contact layers, are described. In an example, an integrated circuit structure includes a gate structure. An epitaxial source or drain structure is adjacent to the gate structure. A conductive trench contact structure is on the epitaxial source or drain structure. The conductive trench contact structure includes a first planar layer on the epitaxial source or drain structure, a second planar layer on the first planar layer, and a conductive fill material on the second planar layer.

Abstract: An integrated circuit device comprising at least one first layer at a bottom of a trench, the at least one layer connecting to a source/drain region of a transistor, the at least one layer comprising metal; a second layer on the at least one first layer, the second layer comprising metal; and a third layer on the at least one first layer and within the trench, the third layer comprising a dielectric material.

Abstract: Contacts to n-type and p-type source/drain regions of field-effect transistors comprise a doped contact metal layer positioned between the fill metal and the source/drain regions. The doped contact metal layer comprises a metal and a semiconductor dopant and is formed by reactive sputtering. By varying the concentration of a reactive gas comprising the dopant in the sputtering environment, the atomic composition of the dopant in the doped contact metal layer can vary as the doped contact metal layer is formed. The presence of doped contact metal layers in source/drain contacts can provide for thermally stable low resistance source/drain contacts by inhibiting dopant diffusion from the source/drain regions to the contact metal. In some embodiments, a non-doped contact metal layer can be positioned between the fill metal and the doped contact metal layer.

Abstract: Contacts to n-type and p-type source/drain regions in complementary metal-oxide semiconductor (CMOS) technologies comprise a diffusion barrier layer positioned between the contact metal and the source/drain regions. The contact metal-diffusion barrier layer pairs used to contact n-type and p-type source/drain regions can comprise different materials. The contact metal layers used in n-type and p-type source/drain contacts can comprise the same or different materials. The presence of diffusion barrier layers can provide for thermally stable low resistance source/drain contacts by inhibiting dopant diffusion from the source/drain regions to the contact metal.

Abstract: Disclosed herein are integrated circuit (IC) devices with contacts using nitridized molybdenum. For example, a contact arrangement for an IC device may include a semiconductor material and a contact extending into a portion of the semiconductor material. The contact may include molybdenum. The molybdenum may be in a first layer and a second layer, where the second layer may further include nitrogen. The first layer may have a thickness between about 5 nanometers and 16 nanometers, and the second layer may have a thickness between about 0.5 nanometers to 2.5 nanometers. The contact may further include a fill material (e.g., an electrically conductive material) and the second layer may be in contact with the fill material. The molybdenum may have a low resistance, and thus may improve the electrical performance of the contact. The nitridized molybdenum may prevent oxidation during the fabrication of the contact.

Abstract: In one embodiment, layers comprising Carbon (e.g., Silicon Carbide) are on source/drain regions of a transistor, e.g., before gate formation and metallization, and the layers comprising Carbon are later removed in the manufacturing process to form electrical contacts on the source/drain regions.

Abstract: Semiconductor structures having a source and/or drain with a refractory metal cap, and methods of forming the same, are described herein. In one example, a semiconductor structure includes a channel, a gate, a source, and a drain. The source and drain contain silicon and germanium, and one or both of the source and drain are capped with a semiconductor cap and a refractory metal cap. The semiconductor cap is on the source and/or drain and contains germanium and boron. The refractory metal cap is on the semiconductor cap and contains a refractory metal.

Abstract: Contacts to p-type source/drain regions comprise a boride, indium, or gallium metal compound layer. The boride, indium, or gallium metal compound layers can aid in forming thermally stable low resistance contacts. A boride, indium, or gallium metal compound layer is positioned between the source/drain region and the contact metal layer. A boride, indium, or gallium metal compound layer can be used in contacts contacting p-type source/drain regions comprising boron, indium, or gallium as the primary dopant, respectively. The boride, indium, or gallium metal compound layers prevent diffusion of boron, indium, or gallium from the source/drain region into the metal contact layer and dopant deactivation in the source/drain region due to annealing and other high-temperature processing steps that occur after contact formation.

Abstract: Contacts to n-type source/drain regions comprise a phosphide or arsenide metal compound layer. The phosphide or arsenide metal compound layers can aid in forming thermally stable low resistance contacts. A phosphide or arsenide metal compound layer is positioned between the source/drain region and the contact metal layer of the contact. A phosphide or arsenic metal compound layer can be used in contacts contacting n-type source/drain regions comprising phosphorous or arsenic as the primary dopant, respectively. The phosphide or arsenide metal compound layers prevent diffusion of phosphorous or arsenic from the source/drain region into the metal contact layer and dopant deactivation in the source/drain region due to annealing and other high-temperature processing steps that occur after contact formation.

Abstract: Contact over active gate (COAG) structures with trench contact layers, and methods of fabricating contact over active gate (COAG) structures using trench contact layers, are described. In an example, an integrated circuit structure includes a gate structure. An epitaxial source or drain structure is adjacent to the gate structure. A conductive trench contact structure is on the epitaxial source or drain structure. The conductive trench contact structure includes a first planar layer on the epitaxial source or drain structure, a second planar layer on the first planar layer, and a conductive fill material on the second planar layer.

Abstract: A transistor includes a semiconductor fin with a subfin layer of a subfin material selected from a first group III-V compound a channel layer of a channel material directly on the subfin layer and extending upwardly therefrom, the channel material being a second group III-V compound different from the first group III-V compound. A gate structure is in direct contact with the channel layer of the semiconductor fin, where the gate structure is further in direct contact with one of (i) a top surface of the subfin layer, the top surface being exposed where the channel layer meets the subfin layer because the channel layer is narrower than the subfin layer, or (ii) a liner layer of liner material in direct contact with opposing sidewalls of the subfin layer, the liner material being distinct from the first and second group III-V compounds.

Abstract: A transistor includes a semiconductor fin with a subfin layer of a subfin material selected from a first group III-V compound a channel layer of a channel material directly on the subfin layer and extending upwardly therefrom, the channel material being a second group III-V compound different from the first group III-V compound. A gate structure is in direct contact with the channel layer of the semiconductor fin, where the gate structure is further in direct contact with one of (i) a top surface of the subfin layer, the top surface being exposed where the channel layer meets the subfin layer because the channel layer is narrower than the subfin layer, or (ii) a liner layer of liner material in direct contact with opposing sidewalls of the subfin layer, the liner material being distinct from the first and second group III-V compounds.

Abstract: Techniques are disclosed for enabling multi-sided condensation of semiconductor fins. The techniques can be employed, for instance, in fabricating fin-based transistors. In one example case, a strain layer is provided on a bulk substrate. The strain layer is associated with a critical thickness that is dependent on a component of the strain layer, and the strain layer has a thickness lower than or equal to the critical thickness. A fin is formed in the substrate and strain layer, such that the fin includes a substrate portion and a strain layer portion. The fin is oxidized to condense the strain layer portion of the fin, so that a concentration of the component in the strain layer changes from a pre-condensation concentration to a higher post-condensation concentration, thereby causing the critical thickness to be exceeded.

Abstract: An embodiment of the invention includes an epitaxial layer that directly contacts, for example, a nanowire, fin, or pillar in a manner that allows the layer to relax with two or three degrees of freedom. The epitaxial layer may be included in a channel region of a transistor. The nanowire, fin, or pillar may be removed to provide greater access to the epitaxial layer. Doing so may allow for a “all-around gate” structure where the gate surrounds the top, bottom, and sidewalls of the epitaxial layer. Other embodiments are described herein.

Abstract: Techniques are disclosed for enabling multi-sided condensation of semiconductor fins. The techniques can be employed, for instance, in fabricating fin-based transistors. In one example case, a strain layer is provided on a bulk substrate. The strain layer is associated with a critical thickness that is dependent on a component of the strain layer, and the strain layer has a thickness lower than or equal to the critical thickness. A fin is formed in the substrate and strain layer, such that the fin includes a substrate portion and a strain layer portion. The fin is oxidized to condense the strain layer portion of the fin, so that a concentration of the component in the strain layer changes from a pre-condensation concentration to a higher post-condensation concentration, thereby causing the critical thickness to be exceeded.

Abstract: Techniques are disclosed for enabling multi-sided condensation of semiconductor fins The techniques can be employed, for instance, in fabricating fin-based transistors. In one example case, a strain layer is provided on a bulk substrate. The strain layer is associated with a critical thickness that is dependent on a component of the strain layer, and the strain layer has a thickness lower than or equal to the critical thickness. A fin is formed in the substrate and strain layer, such that the fin includes a substrate portion and a strain layer portion. The fin is oxidized to condense the strain layer portion of the fin, so that a concentration of the component in the strain layer changes from a pre-condensation concentration to a higher post-condensation concentration, thereby causing the critical thickness to be exceeded.