Abstract: A process for producing monocrystalline semiconductor layers. In an exemplary embodiment, a graded Si1−xGex (x increases from 0 to y) is deposited on a first silicon substrate, followed by deposition of a relaxed Si1−yGey layer, a thin strained Si1−zGez layer and another relaxed Si1−yGey layer. Hydrogen ions are then introduced into the strained SizGez layer. The relaxed Si1−yGey layer is bonded to a second oxidized substrate. An annealing treatment splits the bonded pair at the strained Si layer, such that the second relaxed Si1−yGey layer remains on the second substrate. In another exemplary embodiment, a graded Si1−xGex is deposited on a first silicon substrate, where the Ge concentration x is increased from 0 to 1. Then a relaxed GaAs layer is deposited on the relaxed Ge buffer. As the lattice constant of GaAs is close to that of Ge, GaAs has high quality with limited dislocation defects.

Abstract: A semiconductor structure including a first substrate, and an epitaxial layer bonded to the substrate. The epitaxial layer has a threading dislocation density of less than 107 cm−2 and an in-plane lattice constant that is different from that of the first substrate and a second substrate on which the epitaxial layer is fabricated. In another embodiment, there is provided a method of processing a semiconductor structure including providing a first substrate; providing a layered structure including a second substrate having an epitaxial layer provided thereon, the epitaxial layer having an in-plane lattice constant that is different from that of the first substrate and a threading dislocation density of less than 107 cm−2; bonding the first substrate to the layered structure; and removing the second substrate.

Abstract: A method of processing semiconductor materials and a corresponding semiconductor structure, including providing a virtual substrate of a GaAs epitaxial film on a Si substrate, and epitaxailly growing a relaxed graded layer of InxGal-xAs at a temperature ranging upwards from about 600° C. with a subsequent process for planarization of the InGaAs alloy.

Abstract: A method of fabricating a buried channel FET including providing a relaxed SiGe layer on a substrate, providing a channel layer on the relaxed SiGe layer, providing a SiGe cap layer on the channel layer, and ion implanting a dopant supply. The dopant supply can be ion implanted in either the SiGe cap layer or the relaxed SiGe layer. In another embodiment, there is provided a method of fabricating a circuit including providing at least one strained channel, enhancement mode FET, and at least one strained channel, depletion mode FET on a substrate, and ion implanting a dopant supply in the depletion mode FET.

Abstract: A method of processing semiconductor materials and a corresponding semiconductor structure, including providing a virtual substrate of a GaAs epitaxial film on a Si substrate, and epitaxially growing a relaxed graded layer of InxGa1−xAs at a temperature ranging upwards from about 600° C. with a subsequent process for planarization of the InGaAs alloy.

Abstract: A method of fabricating a semiconductor device including providing a semiconductor heterostructure, the heterostructure having a relaxed Si1−xGex layer on a substrate, a strained channel layer on the relaxed Si1−xGex layer, and a Si1−yGey layer; removing the Si1−yGey layer; and providing a dielectric layer. The dielectric layer includes a gate dielectric of a MISFET. In alternative embodiments, the heterostructure includes a SiGe spacer layer and a Si layer.

Abstract: A semiconductor structure and method of processing same including a substrate, a lattice-mismatched first layer deposited on the substrate and annealed at a temperature greater than 100° C. above the deposition temperature, and a second layer deposited on the first layer with a greater lattice mismatch to the substrate than the first semiconductor layer. In another embodiment there is provided a semiconductor graded composition layer structure on a semiconductor substrate and a method of processing same including a semiconductor substrate, a first semiconductor layer having a series of lattice-mismatched semiconductor layers deposited on the substrate and annealed at a temperature greater than 100° C. above the deposition temperature, a second semiconductor layer deposited on the first semiconductor layer with a greater lattice mismatch to the substrate than the first semiconductor layer, and annealed at a temperature greater than 100° C.

Abstract: A process for producing monocrystalline semiconductor layers. In an exemplary embodiment, a graded Si1−xGex (x increases from 0 to y) is deposited on a first silicon substrate, followed by deposition of a relaxed Si1−yGey layer, a thin strained Si1−zGez layer and another relaxed Si1−yGey layer. Hydrogen ions are then introduced into the strained SizGez layer. The relaxed Si1−yGey layer is bonded to a second oxidized substrate. An annealing treatment splits the bonded pair at the strained Si layer, such that the second relaxed Si1−yGey layer remains on the second substrate. In another exemplary embodiment, a graded Si1−xGex is deposited on a first silicon substrate, where the Ge concentration x is increased from 0 to 1. Then a relaxed GaAs layer is deposited on the relaxed Ge buffer. As the lattice constant of GaAs is close to that of Ge, GaAs has high quality with limited dislocation defects.

Abstract: Structures and methods for fabricating high speed digital, analog, and combined digital/analog systems using planarized relaxed SiGe as the materials platform. The relaxed SiGe allows for a plethora of strained Si layers that possess enhanced electronic properties. By allowing the MOSFET channel to be either at the surface or buried, one can create high-speed digital and/or analog circuits. The planarization before the device epitaxial layers are deposited ensures a flat surface for state-of-the-art lithography.

Abstract: A circuit including at least one strained channel, enhancement mode FET, and at least one strained channel, depletion mode FET. The depletion mode FET includes an ion implanted dopant supply. In exemplary embodiments, the FETs are surface channel or buried channel MOSFETS. In another exemplary embodiment, the FETs are interconnected to form an inverter.

Abstract: Semiconductor structures and devices including strained material layers having impurity-free zones, and methods for fabricating same. Certain regions of the strained material layers are kept free of impurities that can interdiffuse from adjacent portions of the semiconductor. When impurities are present in certain regions of the strained material layers, there is degradation in device performance. By employing semiconductor structures and devices (e.g., field effect transistors or “FETs”) that have the features described, or are fabricated in accordance with the steps described, device operation is enhanced.

Abstract: A semiconductor-based device includes a channel layer, which includes a distal layer and a proximal layer in contact with the distal layer. The distal layer supports at least a portion of hole conduction for at least one p-channel component, and the proximal layer supports at least a portion of electron conduction for at least one n-channel component. The proximal layer has a thickness that permits a hole wave function to effectively extend from the proximal layer into the distal layer to facilitate hole conduction by the distal layer. A method for fabricating a semiconductor-based device includes providing a distal portion of a channel layer and providing a proximal portion of the channel layer.

Abstract: Semiconductor-based devices, and methods for making the devices, involve a first device that includes a buried channel layer, a dielectric layer, and a compositionally graded spacer layer. The spacer layer includes a first material and a second material, and is located between the buried channel layer and the dielectric layer. A second device includes a buried channel layer, a relaxed surface layer, and a spacer layer located between the buried channel layer and the relaxed surface layer. The spacer layer has a composition that is different from a composition of the relaxed layer. The spacer layer and the relaxed surface layer each have bandgap offsets relative to the buried channel layer to reduce a parasitic channel conduction. A substrate for fabrication of devices, and methods for making the substrate, involves a substrate that includes a first layer, such as a silicon wafer, a substantially uniform second layer, and a graded-composition third layer.

Abstract: The invention provides semiconductor structure comprising a strained Ge channel layer, and a gate dielectric disposed over the strained Ge channel layer. In one aspect of the invention, a strained Ge channel MOSFET is provided. The strained Ge channel MOSFET includes a relaxed SiGe virtual substrate with a Ge content between 50-95%, and a strained Ge channel formed on the virtual substrate. A gate structure is formed upon the strained Ge channel, whereupon a MOSFET is formed with increased performance over bulk Si. In another embodiment of the invention, a semiconductor structure comprising a relaxed Ge channel layer and a virtual substrate, wherein the relaxed Ge channel layer is disposed above the virtual substrate. In a further aspect of the invention, a relaxed Ge channel MOSFET is provided. The method includes providing a relaxed virtual substrate with a Ge composition of approximately 100% and a relaxed Ge channel formed on the virtual substrate.

Abstract: A CMOS inverter having a heterostructure including a Si substrate, a relaxed Si1-xGex layer on the Si substrate, and a strained surface layer on said relaxed Si1-xGex layer; and a pMOSFET and an nMOSFET, wherein the channel of said pMOSFET and the channel of the nMOSFET are formed in the strained surface layer. Another embodiment provides an integrated circuit having a heterostructure including a Si substrate, a relaxed Si1-xGex layer on the Si substrate, and a strained layer on the relaxed Si1-xGex layer; and a p transistor and an n transistor formed in the heterostructure, wherein the strained layer comprises the channel of the n transistor and the p transistor, and the n transistor and the p transistor are interconnected in a CMOS circuit.

Abstract: A SiGe monocrystalline etch-stop material system on a monocrystalline silicon substrate. The etch-stop material system can vary in exact composition, but is a doped or undoped Si1−xGex alloy with x generally between 0.2 and 0.5. Across its thickness, the etch-stop material itself is uniform in composition. The etch stop is used for micromachining by aqueous anisotropic etchants of silicon such as potassium hydroxide, sodium hydroxide, lithium hydroxide, ethylenediamine/pyrocatechol/pyrazine (EDP), TMAH, and hydrazine. For example, a cantilever can be made of this etch-stop material system, then released from its substrate and surrounding material, i.e., “micromachined”, by exposure to one of these etchants. These solutions generally etch any silicon containing less than 7×1019 cm−3 of boron or undoped Si1−xGex alloys with x less than approximately 18. Alloying silicon with moderate concentrations of germanium leads to excellent etch selectivities, i.e.

Abstract: A semiconductor structure and method of processing same including a substrate, a lattice-mismatched first layer deposited on the substrate and annealed at a temperature greater than 100° C. above the deposition temperature, and a second layer deposited on the first layer with a greater lattice mismatch to the substrate than the first semiconductor layer. In another embodiment there is provided a semiconductor graded composition layer structure on a semiconductor substrate and a method of processing same including a semiconductor substrate, a first semiconductor layer having a series of lattice-mismatched semiconductor layers deposited on the substrate and annealed at a temperature greater than 100° C. above the deposition temperature, a second semiconductor layer deposited on the first semiconductor layer with a greater lattice mismatch to the substrate than the first semiconductor layer, and annealed at a temperature greater than 100° C.

Abstract: A structure and a method for forming the structure, the method including forming a compressively strained semiconductor layer, the compressively strained layer having a strain greater than or equal to 0.25%. A tensilely strained semiconductor layer is formed over the compressively strained layer. The compressively strained layer is substantially planar, having a surface roughness characterized in (i) having an average wavelength greater than an average wavelength of a carrier in the compressively strained layer or (ii) having an average height less than 10 nm.

Abstract: A semiconductor structure and method of processing same including a substrate, a lattice-mismatched first layer deposited on the substrate and annealed at a temperature greater than 100° C. above the deposition temperature, and a second layer deposited on the first layer with a greater lattice mismatch to the substrate than the first semiconductor layer. In another embodiment there is provided a semiconductor graded composition layer structure on a semiconductor substrate and a method of processing same including a semiconductor substrate, a first semiconductor layer having a series of lattice-mismatched semiconductor layers deposited on the substrate and annealed at a temperature greater than 100° C. above the deposition temperature, a second semiconductor layer deposited on the first semiconductor layer with a greater lattice mismatch to the substrate than the first semiconductor layer, and annealed at a temperature greater than 100° C.

Abstract: A structure includes a tensile strained layer disposed over a substrate, the tensile strained layer having a first thickness. A compressed layer is disposed between the tensile strained layer and the substrate, the compressed layer having a second thickness. The first and second thicknesses are selected to define a first carrier mobility in the tensile strained layer and a second carrier mobility in the compressed layer.