Abstract: Embodiments of the disclosure are in the field of advanced integrated circuit structure fabrication and, in particular, integrated circuit structures having germanium-based channels are described. In an example, an integrated circuit structure includes a fin having a lower silicon portion, an intermediate germanium portion on the lower silicon portion, and a silicon germanium portion on the intermediate germanium portion. An isolation structure is along sidewalls of the lower silicon portion of the fin. A gate stack is over a top of and along sidewalls of an upper portion of the fin and on a top surface of the isolation structure. A first source or drain structure is at a first side of the gate stack. A second source or drain structure is at a second side of the gate stack.

Abstract: Techniques are disclosed for forming column IV transistor devices having source/drain regions with high concentrations of germanium, and exhibiting reduced parasitic resistance relative to conventional devices. In some example embodiments, the source/drain regions each includes a thin p-type silicon or germanium or SiGe deposition with the remainder of the source/drain material deposition being p-type germanium or a germanium alloy (e.g., germanium:tin or other suitable strain inducer, and having a germanium content of at least 80 atomic % and 20 atomic % or less other components). In some cases, evidence of strain relaxation may be observed in the germanium rich cap layer, including misfit dislocations and/or threading dislocations and/or twins. Numerous transistor configurations can be used, including both planar and non-planar transistor structures (e.g., FinFETs and nanowire transistors), as well as strained and unstrained channel structures.

Abstract: Monolithic FETs including a majority carrier channel in a first high carrier mobility semiconductor material disposed over a substrate. While a mask, such as a gate stack or sacrificial gate stack, is covering a lateral channel region, a spacer of a high carrier mobility semiconductor material is overgrown, for example wrapping around a dielectric lateral spacer, to increase effective spacing between the transistor source and drain without a concomitant increase in transistor footprint. Source/drain regions couple electrically to the lateral channel region through the high-mobility semiconductor spacer, which may be substantially undoped (i.e. intrinsic). With effective channel length for a given lateral gate dimension increased, the transistor footprint for a given off-state leakage may be reduced or off-state source/drain leakage for a given transistor footprint may be reduced, for example.

Abstract: Methods of forming a strained channel device utilizing dislocations disposed in source/drain structures are described. Those methods and structures may include forming a thin silicon germanium material in a source/drain opening of a device comprising silicon, wherein multiple dislocations are formed in the silicon germanium material. A source/drain material may be formed on the thin silicon germanium material, wherein the dislocations induce a tensile strain in a channel region of the device.

Abstract: Techniques are disclosed for forming diverse transistor channel materials enabled by a thin, inverse-graded, germanium (Ge)-based layer. The thin, inverse-graded, Ge-based layer (e.g., having a thickness of at most 500 nm) can then serve as a template for the growth of compressively strained PMOS channel material and tensile strained NMOS channel material to achieve gains in hole and electron mobility, respectively, in the channel regions of the devices. Such a relatively thin Ge-based layer can be formed with suitable surface quality/relaxation levels due to the inverse grading of the Ge concentration in the layer, where the Ge concentration is relatively greatest near the substrate and relatively lowest near the overlying channel material layer. In addition to the inverse-graded Ge concentration, the Ge-based layer may be characterized by the nucleation, and predominant containment, of defects at/near the interface between the substrate and the Ge-based layer.

Abstract: Methods of forming a strained channel device utilizing dislocations disposed in source/drain structures are described. Those methods and structures may include forming a thin silicon germanium material in a source/drain opening of a device comprising silicon, wherein multiple dislocations are formed in the silicon germanium material. A source/drain material may be formed on the thin silicon germanium material, wherein the dislocations induce a tensile strain in a channel region of the device.

Abstract: Techniques are disclosed for forming transistor devices having source and drain regions with high concentrations of boron doped germanium. In some embodiments, an in situ boron doped germanium, or alternatively, boron doped silicon germanium capped with a heavily boron doped germanium layer, are provided using selective epitaxial deposition in the source and drain regions and their corresponding tip regions. In some such cases, germanium concentration can be, for example, in excess of 50 atomic % and up to 100 atomic %, and the boron concentration can be, for instance, in excess of 1E20 cm?3. A buffer providing graded germanium and/or boron concentrations can be used to better interface disparate layers. The concentration of boron doped in the germanium at the epi-metal interface effectively lowers parasitic resistance without degrading tip abruptness. The techniques can be embodied, for instance, in planar or non-planar transistor devices.

Abstract: High-purity Ge channeled N-type transistors include a Si-based barrier material separating the channel from a Ge source and drain that is heavily doped with an N-type impurity. The barrier material may have nanometer thickness and may also be doped with N-type impurities. Because of the Si content, N-type impurities have lower diffusivity within the barrier material and can be prevented from entering high-purity Ge channel material. In addition to Si, a barrier material may also include C. With the barrier material, an N-type transistor may display higher channel mobility and reduced short-channel effects.

Abstract: A method including forming a fin of a nonplanar device on a substrate, the fin including a second layer between a first layer and a third layer; replacing the second layer with a dielectric material; and forming a gate stack on a channel region of the fin. An apparatus including a first multigate device on a substrate including a fin including a conducting layer on a dielectric layer, a gate stack disposed on the conducting layer in a channel region of the fin, and a source and a drain formed in the fin, and a second multigate device on the substrate including a fin including a first conducting layer and a second conducting layer separated by a dielectric layer, a gate stack disposed the first conducting layer and the second conducting layer in a channel region of the fin, and a source and a drain formed in the fin.

Abstract: Integrated circuit transistor structures are disclosed that reduce band-to-band tunneling between the channel region and the source/drain region of the transistor, without adversely increasing the extrinsic resistance of the device. In an example embodiment, the structure includes one or more spacer configured to separate the source and/or drain from the channel region. The spacer(s) regions comprise a semiconductor material that provides a relatively high conduction band offset (CBO) and a relatively low valence band offset (VBO) for PMOS devices, and a relatively high VBO and a relatively low CBO for NMOS devices. In some cases, the spacer includes silicon, germanium, and carbon (e.g., for devices having germanium channel). The proportions may be at least 10% silicon by atomic percentage, at least 85% germanium by atomic percentage, and at least 1% carbon by atomic percentage. Other embodiments are implemented with III-V materials.

Abstract: Techniques are disclosed for using compositionally different contact materials for p-type and n-type source/drain regions on a common substrate. The different contact materials may be within a common source/drain contact trench, or in type-dedicated trenches. A given contact trench may span one or more fins and include one or more source/drain regions on which a corresponding contact structure is to be made. In an embodiment, an isolation structure between p-type and n-type fins is selective to the trench etch and therefore remains intact within the trench after the target source/drain regions have been exposed. In such cases, the isolation structure physically separates n-type source/drain regions from p-type source/drain regions. The contact structures on the different type source/drain regions may be shorted proximate the top of the isolation structure. Numerous material systems can be used for the channel and source/drain regions, including germanium, group III-V materials, and 2-D materials.

Abstract: Techniques are disclosed for forming transistor devices having reduced parasitic contact resistance relative to conventional devices. The techniques can be implemented, for example, using a standard contact stack such as a series of metals on, for example, silicon or silicon germanium (SiGe) source/drain regions. In accordance with one example such embodiment, an intermediate boron doped germanium layer is provided between the source/drain and contact metals to significantly reduce contact resistance. Numerous transistor configurations and suitable fabrication processes will be apparent in light of this disclosure, including both planar and non-planar transistor structures (e.g., FinFETs), as well as strained and unstrained channel structures. Graded buffering can be used to reduce misfit dislocation. The techniques are particularly well-suited for implementing p-type devices, but can be used for n-type devices if so desired.

Abstract: Low resistance approaches for fabricating contacts, and semiconductor structures having low resistance metal contacts, are described. In an example, an integrated circuit structure includes a semiconductor structure above a substrate. A gate electrode is over the semiconductor structure, the gate electrode defining a channel region in the semiconductor structure. A first semiconductor source or drain structure is at a first end of the channel region at a first side of the gate electrode. A second semiconductor source or drain structure is at a second end of the channel region at a second side of the gate electrode, the second end opposite the first end. A source or drain contact is directly on the first or second semiconductor source or drain structure, the source or drain contact including a barrier layer and an inner conductive structure.

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.

Abstract: Self-aligned gate endcap (SAGE) architectures without fin end gaps, and methods of fabricating self-aligned gate endcap (SAGE) architectures without fin end gaps, are described. In an example, an integrated circuit structure includes a semiconductor fin having a cut along a length of the semiconductor fin. A gate endcap isolation structure is in a location of the cut of the semiconductor fin and in contact with the semiconductor fin.

Abstract: Co-integrated gallium nitride (GaN) complementary metal oxide semiconductor (CMOS) integrated circuit technology is described. In an example, a semiconductor structure includes a silicon (111) substrate having a first region and a second region. A structure including gallium and nitrogen is on the first region of the silicon (111) substrate, the structure including gallium and nitrogen having a top surface. A structure including germanium is on the second region of the silicon (111) substrate, the structure including germanium having a top surface co-planar with the top surface of the structure including gallium and nitrogen. A dielectric spacer is laterally between and in contact with the structure including gallium and nitrogen and the structure including germanium, the dielectric spacer on the silicon (111) substrate.

Abstract: Techniques and methods related to strained NMOS and PMOS devices without relaxed substrates, systems incorporating such semiconductor devices, and methods therefor may include a semiconductor device that may have both n-type and p-type semiconductor bodies. Both types of semiconductor bodies may be formed from an initially strained semiconductor material such as silicon germanium. A silicon cladding layer may then be provided at least over or on the n-type semiconductor body. In one example, a lower portion of the semiconductor bodies is formed by a Si extension of the wafer or substrate. By one approach, an upper portion of the semiconductor bodies, formed of the strained SiGe, may be formed by blanket depositing the strained SiGe layer on the Si wafer, and then etching through the SiGe layer and into the Si wafer to form the semiconductor bodies or fins with the lower and upper portions.

Abstract: Methods of forming a strained channel device utilizing dislocations disposed in source/drain structures are described. Those methods and structures may include forming a thin silicon germanium material in a source/drain opening of a device comprising silicon, wherein multiple dislocations are formed in the silicon germanium material. A source/drain material may be formed on the thin silicon germanium material, wherein the dislocations induce a tensile strain in a channel region of the device.

Abstract: Techniques are disclosed for forming transistor devices having reduced parasitic contact resistance relative to conventional devices. The techniques can be implemented, for example, using a standard contact stack such as a series of metals on, for example, silicon or silicon germanium (SiGe) source/drain regions. In accordance with one example such embodiment, an intermediate boron doped germanium layer is provided between the source/drain and contact metals to significantly reduce contact resistance. Numerous transistor configurations and suitable fabrication processes will be apparent in light of this disclosure, including both planar and non-planar transistor structures (e.g., FinFETs), as well as strained and unstrained channel structures. Graded buffering can be used to reduce misfit dislocation. The techniques are particularly well-suited for implementing p-type devices, but can be used for n-type devices if so desired.

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.