Abstract:
When forming sophisticated semiconductor devices on the basis of high-k metal gate electrode structures, which are to be provided in an early manufacturing stage, the encapsulation of the sensitive gate materials may be improved by reducing the depth of or eliminating recessed areas that are obtained after forming sophisticated trench isolation regions. To this end, after completing the STI module, an additional fill material may be provided so as to obtain the desired surface topography and also preserve superior material characteristics of the trench isolation regions.
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:
Improved semiconductor devices comprising 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:
Methods for forming a semiconductor device comprising a silicon-comprising substrate are provided. One exemplary method comprises depositing a polysilicon layer overlying the silicon-comprising substrate, amorphizing the polysilicon layer, etching the amorphized polysilicon layer to form a gate electrode, etching recesses into the substrate using the gate electrode as an etch mask, depositing a stress-inducing layer overlying the gate electrode, annealing the silicon-comprising substrate to recrystallize the gate electrode, removing the stress-inducing layer, and epitaxially growing impurity-doped, silicon-comprising regions in the recesses.
Abstract:
Methods are provided for forming a semiconductor device comprising a semiconductor substrate. In accordance with an exemplary embodiment, a method comprises the steps of forming a high-k dielectric layer overlying the semiconductor substrate, forming a metal-comprising gate layer overlying the high-k dielectric layer, forming a doped silicon-comprising capping layer overlying the metal-comprising gate layer, and depositing a silicon-comprising gate layer overlying the doped silicon-comprising capping layer.
Abstract:
Methods for fabricating semiconductor devices are provided. The methods include providing a semiconductor substrate having pFET and nFET regions, each having active areas and shallow trench isolation. A hardmask layer is formed overlying the semiconductor substrate. A photoresist layer is provided over the hardmask layer. The phoresist layer is patterned. An exposed portion of the hardmask layer is removed from one of the pFET region and nFET region with the patterned photoresist acting as an etch mask to define a masked region and an unmasked region. An epitaxial silicon layer is formed on the active area in the unmasked region. A protective oxide layer is formed overlying the epitaxial silicon layer. The hardmask layer is removed from the masked region with the protective oxide layer protecting the epitaxial silicon layer during such removal step. The protective oxide layer is removed from the epitaxial silicon layer.
Abstract:
Improved semiconductor devices comprising 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:
Sophisticated gate electrode structures may be formed by providing a cap layer including a desired species that may diffuse into the gate dielectric material prior to performing a treatment for stabilizing the sensitive gate dielectric material. In this manner, complex high-k metal gate electrode structures may be formed on the basis of reduced temperatures and doses for a threshold adjusting species compared to conventional strategies.
Abstract:
Methods for forming a semiconductor device comprising a silicon-comprising substrate are provided. One exemplary method comprises depositing a polysilicon layer overlying the silicon-comprising substrate, amorphizing the polysilicon layer, etching the amorphized polysilicon layer to form a gate electrode, etching recesses into the substrate using the gate electrode as an etch mask, depositing a stress-inducing layer overlying the gate electrode, annealing the silicon-comprising substrate to recrystallize the gate electrode, removing the stress-inducing layer, and epitaxially growing impurity-doped, silicon-comprising regions in the recesses.
Abstract:
Methods are provided for forming a semiconductor device comprising a semiconductor substrate. In accordance with an exemplary embodiment, a method comprises the steps of forming a high-k dielectric layer overlying the semiconductor substrate, forming a metal-comprising gate layer overlying the high-k dielectric layer, forming a doped silicon-comprising capping layer overlying the metal-comprising gate layer, and depositing a silicon-comprising gate layer overlying the doped silicon-comprising capping layer.