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. Sacrificial fins are removed via wet and/or dry etch chemistries configured to provide trench bottoms that are non-faceted and have no or otherwise low-ion damage. The trench is then filled with desired semiconductor material. A trench bottom having low-ion damage and non-faceted morphology encourages a defect-free or low defect interface between the substrate and the replacement material. In an embodiment, each of a first set of the sacrificial silicon fins is recessed and replaced with a p-type material, and each of a second set of the sacrificial fins is recessed and replaced with an n-type material. Another embodiment may include a combination of native fins (e.g., Si) and replacement fins (e.g., SiGe). Another embodiment may include replacement fins all of the same configuration.
Abstract:
Techniques are disclosed for resistance reduction in p-MOS transistors having epitaxially grown boron-doped silicon germanium (SiGe:B) S/D regions. The techniques can include growing one or more interface layers between a silicon (Si) channel region of the transistor and the SiGe:B replacement S/D regions. The one or more interface layers may include: a single layer of boron-doped Si (Si:B); a single layer of SiGe:B, where the Ge content in the interface layer is less than that in the resulting SiGe:B S/D regions; a graded layer of SiGe:B, where the Ge content in the alloy starts at a low percentage (or 0%) and is increased to a higher percentage; or multiple stepped layers of SiGe:B, where the Ge content in the alloy starts at a low percentage (or 0%) and is increased to a higher percentage at each step. Inclusion of the interface layer(s) reduces resistance for on-state current flow.
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 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:
A process is described for manufacturing an improved PMOS semiconductor transistor. Recesses are etched into a layer of epitaxial silicon. Source and drain films are deposited in the recesses. The source and drain films are made of an alloy of silicon and germanium. The alloy is epitaxially deposited on the layer of silicon. The alloy thus has a lattice having the same structure as the structure of the lattice of the layer of silicon. However, due to the inclusion of the germanium, the lattice of the alloy has a larger spacing than the spacing of the lattice of the layer of silicon. The larger spacing creates a stress in a channel of the transistor between the source and drain films. The stress increases IDSAT and IDLIN of the transistor. An NMOS transistor can be manufactured in a similar manner by including carbon instead of germanium, thereby creating a tensile stress.
Abstract:
Techniques are disclosed for forming contacts in silicon semiconductor devices. In some embodiments, a transition layer forms a non-reactive interface with the silicon semiconductor contact surface. In some such cases, a conductive material provides the contacts and the material forming a non-reactive interface with the silicon surface. In other cases, a thin semiconducting or insulating layer provides the non-reactive interface with the silicon surface and is coupled to conductive material of the contacts. The techniques can be embodied, for instance, in planar or non-planar (e.g., double-gate and tri-gate FinFETs) transistor devices.
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.