Abstract:
Semiconductor transistor devices and related fabrication methods are provided. An exemplary transistor device includes a layer of semiconductor material having a channel region defined therein and a gate structure overlying the channel region. Recesses are formed in the layer of semiconductor material adjacent to the channel region, such that the recesses extend asymmetrically toward the channel region. The transistor device also includes stress-inducing semiconductor material formed in the recesses. The asymmetric profile of the stress-inducing semiconductor material enhances carrier mobility in a manner that does not exacerbate the short channel effect.
Abstract:
Methods for protecting gate stacks during fabrication of semiconductor devices and semiconductor devices fabricated from such methods are provided. In an embodiment, a method for fabricating a semiconductor device comprises forming a gate stack comprising a first gate stack-forming layer overlying a semiconductor substrate and forming first sidewall spacers about sidewalls of the gate stack. After the step of forming the first sidewall spacers, a portion of the first gate stack-forming layer is exposed. The exposed portion is anisotropically etched using the gate stack and the first sidewall spacers as an etch mask. Second sidewall spacers are formed adjacent the first sidewall spacers after the step of anisotropically etching.
Abstract:
A low energy surface is formed by a high temperature anneal of the surfaces of trenches on each side of a gate stack. The material of the semiconductor layer reflows during the high temperature anneal such that the low energy surface is a crystallographic surface that is at a non-orthogonal angle with the surface normal of the semiconductor layer. A lattice mismatched semiconductor material is selectively grown on the semiconductor layer to fill the trenches, thereby forming embedded lattice mismatched semiconductor material portions in source and drain regions of a transistor. The embedded lattice mismatched semiconductor material portions can be in-situ doped without increasing punch-through. Alternately, a combination of intrinsic selective epitaxy and ion implantation can be employed to form deep source and drain regions.
Abstract:
A metal oxide semiconductor transistor device having a reduced gate height is provided. One embodiment of the device includes a substrate having a layer of semiconductor material, a gate structure overlying the layer of semiconductor material, and source/drain recesses formed in the semiconductor material adjacent to the gate structure, such that remaining semiconductor material is located below the source/drain recesses. The device also includes shallow source/drain implant regions formed in the remaining semiconductor material, and epitaxially grown, in situ doped, semiconductor material in the source/drain recesses.
Abstract:
Methods for protecting gate stacks during fabrication of semiconductor devices and semiconductor devices fabricated from such methods are provided. In an embodiment, a method for fabricating a semiconductor device comprises forming a gate stack comprising a first gate stack-forming layer overlying a semiconductor substrate and forming first sidewall spacers about sidewalls of the gate stack. After the step of forming the first sidewall spacers, a portion of the first gate stack-forming layer is exposed. The exposed portion is anisotropically etched using the gate stack and the first sidewall spacers as an etch mask. Second sidewall spacers are formed adjacent the first sidewall spacers after the step of anisotropically etching.
Abstract:
The present disclosure provides manufacturing techniques in which sophisticated high-k metal gate electrode structures may be formed in an early manufacturing stage on the basis of a selectively applied threshold voltage adjusting semiconductor alloy. In order to reduce the surface topography upon patterning the deposition mask while still allowing the usage of well-established epitaxial growth recipes developed for silicon dioxide-based hard mask materials, a silicon nitride base material may be used in combination with a surface treatment. In this manner, the surface of the silicon nitride material may exhibit a silicon dioxide-like behavior, while the patterning of the hard mask may be accomplished on the basis of highly selective etch techniques.
Abstract:
Improved semiconductor devices including metal gate electrodes are formed with reduced performance variability by reducing the initial high dopant concentration at the top portion of the silicon layer overlying the metal layer. Embodiments include reducing the dopant concentration in the upper portion of the silicon layer, by implanting a counter-dopant into the upper portion of the silicon layer, removing the high dopant concentration portion and replacing it with undoped or lightly doped silicon, and applying a gettering agent to the upper surface of the silicon layer to form a thin layer with the gettered dopant, which layer can be removed or retained.
Abstract:
A low energy surface is formed by a high temperature anneal of the surfaces of trenches on each side of a gate stack. The material of the semiconductor layer reflows during the high temperature anneal such that the low energy surface is a crystallographic surface that is at a non-orthogonal angle with the surface normal of the semiconductor layer. A lattice mismatched semiconductor material is selectively grown on the semiconductor layer to fill the trenches, thereby forming embedded lattice mismatched semiconductor material portions in source and drain regions of a transistor. The embedded lattice mismatched semiconductor material portions can be in-situ doped without increasing punch-through. Alternately, a combination of intrinsic selective epitaxy and ion implantation can be employed to form deep source and drain regions.
Abstract:
Semiconductor devices with high-K/metal gates are formed with spacers that are substantially resistant to subsequent etching to remove an overlying spacer, thereby avoiding replacement and increasing manufacturing throughput. Embodiments include forming a high-K/metal gate, having an upper surface and side surfaces, over a substrate, e.g., a SOI substrate, and sequentially forming, on the side surfaces of the high-K/metal gate, a first spacer of a non-oxide material, a second spacer, of a material different from that of the first spacer, and a third spacer, of a material different from that of the second spacer. After formation of source and drain regions, e.g., epitaxially grown silicon-germanium, the third spacer is etched with an etchant, such as hot phosphoric acid, to which the second spacer is substantially resistant, thereby avoiding replacement.
Abstract:
The disclosed subject matter relates to semiconductor transistor devices and associated fabrication techniques that can be utilized to form silicide contacts having an increased effective size, relative to conventional silicide contacts. A semiconductor device fabricated in accordance with the processes disclosed herein includes a layer of semiconductor material and a gate structure overlying the layer of semiconductor material. A channel region is formed in the layer of semiconductor material, the channel region underlying the gate structure. The semiconductor device also includes source and drain regions in the layer of semiconductor material, wherein the channel region is located between the source and drain regions. Moreover, the semiconductor device includes facet-shaped silicide contact areas overlying the source and drain regions.