Abstract: Techniques are disclosed for forming transistor devices having reduced parasitic contact resistance relative to conventional devices. In some example embodiments, the techniques can be used to implement the contacts of MOS transistors of a CMOS device, where an intermediate III-V semiconductor material layer is provided between the p-type and n-type source/drain regions and their respective contact metals to significantly reduce contact resistance. The intermediate III-V semiconductor material layer may have a small bandgap (e.g., lower than 0.5 eV) and/or otherwise be doped to provide the desired conductivity. The techniques can be used on numerous transistor architectures (e.g., planar, finned, and nanowire transistors), including strained and unstrained channel structures.

Abstract: Common-substrate semiconductor devices having nanowires or semiconductor bodies with differing material orientation or composition and methods to form such common-substrate devices are described. For example, a semiconductor structure includes a first semiconductor device having a first nanowire or semiconductor body disposed above a crystalline substrate. The first nanowire or semiconductor body is composed of a semiconductor material having a first global crystal orientation. The semiconductor structure also includes a second semiconductor device having a second nanowire or semiconductor body disposed above the crystalline substrate. The second nanowire or semiconductor body is composed of a semiconductor material having a second global crystal orientation different from the first global orientation. The second nanowire or semiconductor body is isolated from the crystalline substrate by an isolation pedestal disposed between the second nanowire or semiconductor body and the crystalline substrate.

Abstract: An embodiment of the invention reduces the external resistance of a transistor by utilizing a silicon germanium alloy for the source and drain regions and a nickel silicon germanium self-aligned silicide (i.e., salicide) layer to form the contact surface of the source and drain regions. The interface of the silicon germanium and the nickel silicon germanium silicide has a lower specific contact resistivity based on a decreased metal-semiconductor work function between the silicon germanium and the silicide and the increased carrier mobility in silicon germanium versus silicon. The silicon germanium may be doped to further tune its electrical properties. A reduction of the external resistance of a transistor equates to increased transistor performance both in switching speed and power consumption.

Abstract: Techniques are disclosed for forming Ge/SiGe-channel and III-V-channel transistors on the same die. The techniques include depositing a pseudo-substrate of Ge/SiGe or III-V material on a Si or insulator substrate. The pseudo-substrate can then be patterned into fins and a subset of the fins can be replaced by the other of Ge/SiGe or III-V material. The Ge/SiGe fins can be used for p-MOS transistors and the III-V material fins can be used for n-MOS transistors, and both sets of fins can be used for CMOS devices, for example. In some instances, only the channel region of the subset of fins are replaced during, for example, a replacement gate process. In some instances, some or all of the fins may be formed into or replaced by one or more nanowires or nanoribbons.

Abstract: Techniques are disclosed for converting a strain-inducing semiconductor buffer layer into an electrical insulator at one or more locations of the buffer layer, thereby allowing an above device layer to have a number of benefits, which in some embodiments include those that arise from being grown on a strain-inducing buffer and having a buried electrical insulator layer. For instance, having a buried electrical insulator layer (initially used as a strain-inducing buffer during fabrication of the above active device layer) between the Fin and substrate of a non-planar integrated transistor circuit may simultaneously enable a low-doped Fin with high mobility, desirable device electrostatics and elimination or otherwise reduction of substrate junction leakage. Also, the presence of such an electrical insulator under the source and drain regions may further significantly reduce junction leakage. In some embodiments, substantially the entire buffer layer is converted to an electrical insulator.

Abstract: Transistor fin elements (e.g., fin or tri gate) may be modified by radio frequency (RF) plasma and/or thermal processing for purpose of dimensional sculpting. The etched, thinned fins may be formed by first forming wider single crystal fins, and after depositing trench oxide material between the wider fins, etching the wider fins using a second etch to form narrower single crystal fins having undamaged top and sidewalls for epitaxially growing active channel material. The second etch may remove a thickness of between a 1 nm and 15 nm of the top surfaces and the sidewalls of the wider fins. It may remove the thickness using (1) chlorine or fluorine based chemistry using low ion energy plasma processing, or (2) low temperature thermal processing that does not damage fins via energetic ion bombardment, oxidation or by leaving behind etch residue that could disrupt the epitaxial growth quality of the second material.

Abstract: Techniques are disclosed for achieving multiple fin dimensions on a single die or semiconductor substrate. In some cases, multiple fin dimensions are achieved by lithographically defining (e.g., hardmasking and patterning) areas to be trimmed using a trim etch process, leaving the remainder of the die unaffected. In some such cases, the trim etch is performed on only the channel regions of the fins, when such channel regions are re-exposed during a replacement gate process. The trim etch may narrow the width of the fins being trimmed (or just the channel region of such fins) by 2-6 nm, for example. Alternatively, or in addition, the trim may reduce the height of the fins. The techniques can include any number of patterning and trimming processes to enable a variety of fin dimensions and/or fin channel dimensions on a given die, which may be useful for integrated circuit and system-on-chip (SOC) applications.

Abstract: Techniques are disclosed for sculpting and cladding the channel region of fins on a semiconductor substrate during a replacement gate process (e.g., for transistor channel applications). The sculpting and cladding can be performed when the channel region of the fins are re-exposed after the dummy gate used in the replacement gate process is removed. The sculpting includes performing a trim etch on the re-exposed channel region of the fins to narrow a width of the fins (e.g., by 2-6 nm). A cladding layer, which may include germanium (Ge) or silicon germanium (SiGe), can then be deposited on the trimmed fins, leaving the source/drain regions of the fins unaffected. The sculpting and cladding may be performed in-situ or without air break to increase the quality of the trimmed fins (e.g., as compared to an ex-situ process).

Abstract: Complimentary metal-oxide-semiconductor nanowire structures are described. For example, a semiconductor structure includes a first semiconductor device. The first semiconductor device includes a first nanowire disposed above a substrate. The first nanowire has a mid-point a first distance above the substrate and includes a discrete channel region and source and drain regions on either side of the discrete channel region. A first gate electrode stack completely surrounds the discrete channel region of the first nanowire. The semiconductor structure also includes a second semiconductor device. The second semiconductor device includes a second nanowire disposed above the substrate. The second nanowire has a mid-point a second distance above the substrate and includes a discrete channel region and source and drain regions on either side of the discrete channel region. The first distance is different from the second distance.

Abstract: Techniques are disclosed for transistor fabrication including a sacrificial protective layer for source/drain (S/D) regions to minimize contact resistance. The sacrificial protective layer may be selectively deposited on S/D regions after such regions have been formed, but prior to the deposition of an insulator layer on the S/D regions. Subsequently, after contact trench etch is performed, an additional etch process may be performed to remove the sacrificial protective layer and expose a clean S/D surface. Thus, the sacrificial protective layer can protect the contact locations of the S/D regions from contamination (e.g., oxidation or nitridation) caused by insulator layer deposition. The sacrificial protective layer can also protect the S/D regions from undesired insulator material remaining on the S/D contact surface, particularly for non-planar transistor structures (e.g., finned or nanowire/nanoribbon transistor structures).

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: Techniques are disclosed for wafer bonding with an encapsulation layer. A first semiconductor substrate is provided. An encapsulation layer is then formed on top of the first semiconductor substrate. The encapsulation layer is formed of an encapsulation material that creates a stable oxide when exposed to an oxidizing agent. A first bonding layer is formed on top of the encapsulation layer. Next, a second semiconductor substrate is provided. A second bonding layer is formed on top of the second bonding layer. Thereafter, the first semiconductor substrate is bonded to the second semiconductor substrate by attaching the first bonding layer to the second bonding layer.

Abstract: Complimentary metal-oxide-semiconductor nanowire structures are described. For example, a semiconductor structure includes a first semiconductor device. The first semiconductor device includes a first nanowire disposed above a substrate. The first nanowire has a mid-point a first distance above the substrate and includes a discrete channel region and source and drain regions on either side of the discrete channel region. A first gate electrode stack completely surrounds the discrete channel region of the first nanowire. The semiconductor structure also includes a second semiconductor device. The second semiconductor device includes a second nanowire disposed above the substrate. The second nanowire has a mid-point a second distance above the substrate and includes a discrete channel region and source and drain regions on either side of the discrete channel region. The first distance is different from the second distance.

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: Techniques are disclosed for converting a strain-inducing semiconductor buffer layer into an electrical insulator at one or more locations of the buffer layer, thereby allowing an above device layer to have a number of benefits, which in some embodiments include those that arise from being grown on a strain-inducing buffer and having a buried electrical insulator layer. For instance, having a buried electrical insulator layer (initially used as a strain-inducing buffer during fabrication of the above active device layer) between the Fin and substrate of a non-planar integrated transistor circuit may simultaneously enable a low-doped Fin with high mobility, desirable device electrostatics and elimination or otherwise reduction of substrate junction leakage. Also, the presence of such an electrical insulator under the source and drain regions may further significantly reduce junction leakage. In some embodiments, substantially the entire buffer layer is converted to an electrical insulator.

Abstract: Common-substrate semiconductor devices having nanowires or semiconductor bodies with differing material orientation or composition and methods to form such common-substrate devices are described. For example, a semiconductor structure includes a first semiconductor device having a first nanowire or semiconductor body disposed above a crystalline substrate. The first nanowire or semiconductor body is composed of a semiconductor material having a first global crystal orientation. The semiconductor structure also includes a second semiconductor device having a second nanowire or semiconductor body disposed above the crystalline substrate. The second nanowire or semiconductor body is composed of a semiconductor material having a second global crystal orientation different from the first global orientation. The second nanowire or semiconductor body is isolated from the crystalline substrate by an isolation pedestal disposed between the second nanowire or semiconductor body and the crystalline substrate.

Abstract: Techniques are disclosed for improved integration of germanium (Ge)-rich p-MOS source/drain contacts to, for example, reduce contact resistance. The techniques include depositing the p-type Ge-rich layer directly on a silicon (Si) surface in the contact trench location, because Si surfaces are favorable for deposition of high quality conductive Ge-rich materials. In one example method, the Ge-rich layer is deposited on a surface of the Si substrate in the source/drain contact trench locations, after removing a sacrificial silicon germanium (SiGe) layer previously deposited in the source/drain locations. In another example method, the Ge-rich layer is deposited on a Si cladding layer in the contact trench locations, where the Si cladding layer is deposited on a functional p-type SiGe layer. In some cases, the Ge-rich layer comprises at least 50% Ge (and may contain tin (Sn) and/or Si) and is boron (B) doped at levels above 1E20 cm?3.

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: Techniques are disclosed for incorporating high mobility strained channels into fin-based NMOS transistors (e.g., FinFETs such as double-gate, trigate, etc), wherein a stress material is cladded onto the channel area of the fin. In one example embodiment, a germanium or silicon germanium film is cladded onto silicon fins in order to provide a desired tensile strain in the core of the fin, although other fin and cladding materials can be used. The techniques are compatible with typical process flows, and cladding deposition can occur at a plurality of locations within typical process flow. In various embodiments, fins may be formed with a minimum width (or later thinned) so as to improve transistor performance. In some embodiments, a thinned fin also increases tensile strain across the core of a cladded fin. In some cases, strain in the core may be further enhanced by adding an embedded silicon epitaxial source and drain.

Abstract: An embodiment of the invention reduces the external resistance of a transistor by utilizing a silicon germanium alloy for the source and drain regions and a nickel silicon germanium self-aligned silicide (i.e., salicide) layer to form the contact surface of the source and drain regions. The interface of the silicon germanium and the nickel silicon germanium silicide has a lower specific contact resistivity based on a decreased metal-semiconductor work function between the silicon germanium and the silicide and the increased carrier mobility in silicon germanium versus silicon. The silicon germanium may be doped to further tune its electrical properties. A reduction of the external resistance of a transistor equates to increased transistor performance both in switching speed and power consumption.