Abstract: Multiple transistor types are formed in a common epitaxial layer by differential out-diffusion from a doped underlayer. Differential out-diffusion affects the thickness of a FET channel, the doping concentration in the FET channel, and distance between the gate dielectric layer and the doped underlayer. Differential out-diffusion may be achieved by differentially applying a dopant migration suppressor such as carbon; differentially doping the underlayer with two or more dopants having the same conductivity type but different diffusivities; and/or differentially applying thermal energy.

Abstract: A method for fabricating field effect transistors using carbon doped silicon layers to substantially reduce the diffusion of a doped screen layer formed below a substantially undoped channel layer includes forming an in-situ epitaxial carbon doped silicon substrate that is doped to form the screen layer in the carbon doped silicon substrate and forming the substantially undoped silicon layer above the carbon doped silicon substrate. The method may include implanting carbon below the screen layer and forming a thin layer of in-situ epitaxial carbon doped silicon above the screen layer. The screen layer may be formed either in a silicon substrate layer or the carbon doped silicon substrate.

Abstract: A semiconductor structure includes a first PMOS transistor element having a gate region with a first gate metal associated with a PMOS work function and a first NMOS transistor element having a gate region with a second metal associated with a NMOS work function. The first PMOS transistor element and the first NMOS transistor element form a first CMOS device. The semiconductor structure also includes a second PMOS transistor that is formed in part by concurrent deposition with the first NMOS transistor element of the second metal associated with a NMOS work function to form a second CMOS device with different operating characteristics than the first CMOS device.

Abstract: A semiconductor structure is formed with a NFET device and a PFET device. The NFET device is formed by masking the PFET device regions of a substrate, forming a screen layer through epitaxial growth and in-situ doping, and forming an undoped channel layer on the screen layer through epitaxial growth. The PFET device is similarly formed by masking the NFET regions of a substrate, forming a screen layer through epitaxial growth and in-situ doping, and forming an undoped channel layer on the screen layer through epitaxial growth. An isolation region is formed between the NFET and the PFET device areas to remove any facets occurring during the separate epitaxial growth phases. By forming the screen layer through in-situ doped epitaxial growth, a reduction in junction leakage is achieved versus forming the screen layer using ion, implantation.

Abstract: A planar transistor with improved performance has a source and a drain on a semiconductor substrate that includes a substantially undoped channel extending between the source and the drain. A gate is positioned over the substantially undoped channel on the substrate. Implanted source/drain extensions contact the source and the drain, with the implanted source/drain extensions having a dopant concentration of less than about 1×1019 atoms/cm3, or alternatively, less than one-quarter the dopant concentration of the source and the drain.

Abstract: Multiple transistor types are formed in a common epitaxial layer by differential out-diffusion from a doped underlayer. Differential out-diffusion affects the thickness of a FET channel, the doping concentration in the FET channel, and distance between the gate dielectric layer and the doped underlayer. Differential out-diffusion may be achieved by differentially applying a dopant migration suppressor such as carbon; differentially doping the underlayer with two or more dopants having the same conductivity type but different diffusivities; and/or differentially applying thermal energy.

Abstract: A semiconductor structure includes first, second, and third transistor elements each having a first screening region concurrently formed therein. A second screening region is formed in the second and third transistor elements such that there is at least one characteristic of the screening region in the second transistor element that is different than the second screening region in the third transistor element.

Abstract: Methods for fabricating semiconductor devices and devices therefrom are provided. A method includes providing a substrate having a semiconducting surface with first and second layers, where the semiconducting surface has a plurality of active regions comprising first and second active regions. In the first active region, the first layer is an undoped layer and the second layer is a highly doped screening layer. The method also includes removing a part of the first layer to reduce a thickness of the substantially undoped layer for at least a portion of the first active region without a corresponding thickness reduction of the first layer in the second active region. The method additionally includes forming semiconductor devices in the plurality of active regions. In the method, the part of the first layer removed is selected based on a threshold voltage adjustment required for the substrate in the portion of the first active region.

Abstract: A structure and method of fabrication thereof relate to a Deeply Depleted Channel (DDC) design, allowing CMOS based devices to have a reduced ?VT compared to conventional bulk CMOS and can allow the threshold voltage VT of FETs having dopants in the channel region to be set much more precisely. The DDC design also can have a strong body effect compared to conventional bulk CMOS transistors, which can allow for significant dynamic control of power consumption in DDC transistors. The semiconductor structure includes an analog device and a digital device each having an epitaxial channel layer where a single gate oxidation layer is on the epitaxial channel layer of NMOS and PMOS transistor elements of the digital device and one of a double and triple gate oxidation layer is on the epitaxial channel layer of NMOS and PMOS transistor elements of the analog device.

Abstract: A method for fabricating a semiconductor structure with a channel stack includes forming a screening layer under a gate of a PMOS transistor element and a NMOS transistor element, forming a threshold voltage control layer on the screening layer, and forming an epitaxial channel layer on the threshold control layer. At least a portion of the epitaxial channel layers for the PMOS transistor element and the NMOS transistor element are formed as a common blanket layer. The screening layer for the PMOS transistor element may include antimony as a dopant material that may be inserted into the structure prior to or after formation of the epitaxial channel layer.

Abstract: A method for fabricating field effect transistors using carbon doped silicon layers to substantially reduce the diffusion of a doped screen layer formed below a substantially undoped channel layer includes forming an in-situ epitaxial carbon doped silicon substrate that is doped to form the screen layer in the carbon doped silicon substrate and forming the substantially undoped silicon layer above the carbon doped silicon substrate. The method may include implanting carbon below the screen layer and forming a thin layer of in-situ epitaxial carbon doped silicon above the screen layer. The screen layer may be formed either in a silicon substrate layer or the carbon doped silicon substrate.

Abstract: A semiconductor structure includes a first PMOS transistor element having a gate region with a first gate metal associated with a PMOS work function and a first NMOS transistor element having a gate region with a second metal associated with a NMOS work function. The first PMOS transistor element and the first NMOS transistor element form a first CMOS device. The semiconductor structure also includes a second PMOS transistor that is formed in part by concurrent deposition with the first NMOS transistor element of the second metal associated with a NMOS work function to form a second CMOS device with different operating characteristics than the first CMOS device.

Abstract: A planar transistor with improved performance has a source and a drain on a semiconductor substrate that includes a substantially undoped channel extending between the source and the drain. A gate is positioned over the substantially undoped channel on the substrate. Implanted source/drain extensions contact the source and the drain, with the implanted source/drain extensions having a dopant concentration of less than about 1×1019 atoms/cm3?, or alternatively, less than one-quarter the dopant concentration of the source and the drain.

Abstract: A structure and method of fabrication thereof relate to a Deeply Depleted Channel (DDC) design, allowing CMOS based devices to have a reduced ?VT compared to conventional bulk CMOS and can allow the threshold voltage VT of FETs having dopants in the channel region to be set much more precisely. The DDC design also can have a strong body effect compared to conventional bulk CMOS transistors, which can allow for significant dynamic control of power consumption in DDC transistors. The semiconductor structure includes an analog device and a digital device each having an epitaxial channel layer where a single gate oxidation layer is on the epitaxial channel layer of NMOS and PMOS transistor elements of the digital device and one of a double and triple gate oxidation layer is on the epitaxial channel layer of NMOS and PMOS transistor elements of the analog device.

Abstract: A method for fabricating a semiconductor structure with a channel stack includes forming a screening layer under a gate of a PMOS transistor element and a NMOS transistor element, forming a threshold voltage control layer on the screening layer, and forming an epitaxial channel layer on the threshold control layer. At least a portion of the epitaxial channel layers for the PMOS transistor element and the NMOS transistor element are formed as a common blanket layer. The screening layer for the PMOS transistor element may include antimony as a dopant material that may be inserted into the structure prior to or after formation of the epitaxial channel layer.

Abstract: An advanced transistor with punch through suppression includes a gate with length Lg, a well doped to have a first concentration of a dopant, and a screening region positioned under the gate and having a second concentration of dopant. The second concentration of dopant may be greater than 5×1018 dopant atoms per cm3. At least one punch through suppression region is disposed under the gate between the screening region and the well. The punch through suppression region has a third concentration of a dopant intermediate between the first concentration and the second concentration of dopant. A bias voltage may be applied to the well region to adjust a threshold voltage of the transistor.

Abstract: A planar transistor with improved performance has a source and a drain on a semiconductor substrate that includes a substantially undoped channel extending between the source and the drain. A gate is positioned over the substantially undoped channel on the substrate. Implanted source/drain extensions contact the source and the drain, with the implanted source/drain extensions having a dopant concentration of less than about 1×1019 atoms/cm3?, or alternatively, less than one-quarter the dopant concentration of the source and the drain.

Abstract: An advanced transistor with punch through suppression includes a gate with length Lg, a well doped to have a first concentration of a dopant, and a screening region positioned under the gate and having a second concentration of dopant. The second concentration of dopant may be greater than 5×1018 dopant atoms per cm3. At least one punch through suppression region is disposed under the gate between the screening region and the well. The punch through suppression region has a third concentration of a dopant intermediate between the first concentration and the second concentration of dopant. A bias voltage may be applied to the well region to adjust a threshold voltage of the transistor.

Abstract: A planar transistor with improved performance has a source and a drain on a semiconductor substrate that includes a substantially undoped channel extending between the source and the drain. A gate is positioned over the substantially undoped channel on the substrate. Implanted source/drain extensions contact the source and the drain, with the implanted source/drain extensions having a dopant concentration of less than about 1×1019 atoms/cm3, or alternatively, less than one-quarter the dopant concentration of the source and the drain.

Abstract: The present invention discloses a method including: providing a substrate; forming recessed regions adjacent to both sides of a gate on the substrate; performing an angled co-implant of a species in two steps with two different energies and two different doses into the recessed regions; forming Silicon-Germanium in the recessed regions; forming source/drain extensions adjacent to both sides of the gate with a dopant; and performing an anneal to activate the dopant.