Abstract: Structures for a field-effect transistor and methods of forming a structure for a field-effect transistor. A first channel region containing a first semiconductor material and a second channel region containing a second semiconductor material are formed over a buried insulating layer of a silicon-on-insulator substrate. A first gate electrode of a first field-effect transistor is formed over the first channel region. A second gate electrode of a second field-effect transistor is formed over the second channel region. The first semiconductor material of the first channel region has a first germanium concentration. The second semiconductor material of the second channel region has a second germanium concentration that is greater than the first germanium concentration in the first semiconductor material of the first channel region.

Abstract: Structures for a field-effect transistor and methods of forming a structure for a field-effect transistor. A first channel region containing a first semiconductor material and a second channel region containing a second semiconductor material are formed over a buried insulating layer of a silicon-on-insulator substrate. A first gate electrode of a first field-effect transistor is formed over the first channel region. A second gate electrode of a second field-effect transistor is formed over the second channel region. The first semiconductor material of the first channel region has a first germanium concentration. The second semiconductor material of the second channel region has a second germanium concentration that is greater than the first germanium concentration in the first semiconductor material of the first channel region.

Abstract: A process for fabricating one transistor, comprising a semiconductor region, comprising a source region, a drain region, and a channel region covered with a gate, comprises: production of an primary etching mask on the surface of the semiconductor region, said mask containing at least one primary aperture; depositing in said primary aperture a block copolymer containing, in alternation, at least first polymer domains and second polymer domains; removing either a series of first polymer domains or a series of second polymer domains in order to create a secondary mask containing secondary apertures; etching said active region through said secondary apertures in order to define nanoscale self-aligned semiconductor features; producing said gate on the surface of said self-aligned semiconductor features.

Abstract: A method for stressing a pattern having a pattern surface, in a layer of semiconductive material that can be silicon on the surface of a stack of layers generated on the surface of a substrate, said stack comprising at least one stress layer of alloy SixGey with x and y being molar fractions, and a buried layer of silicon oxide, comprises: etching at the periphery of a surface of dimensions greater than said pattern surface, of the buried layer of silicon oxide and layer of alloy SixGey over a part of the depth of said layer of alloy; the buried layer of silicon oxide being situated between said layer of semiconductive material and said stress layer of alloy SixGey. In a transistor structure, etching at the periphery of said surface obtains a pattern thus defined having dimensions greater than the area of interest situated under the gate of the transistor.

Abstract: A process for fabricating one transistor, comprising a semiconductor region, comprising a source region, a drain region, and a channel region covered with a gate, comprises: production of an primary etching mask on the surface of the semiconductor region, said mask containing at least one primary aperture; depositing in said primary aperture a block copolymer containing, in alternation, at least first polymer domains and second polymer domains; removing either a series of first polymer domains or a series of second polymer domains in order to create a secondary mask containing secondary apertures; etching said active region through said secondary apertures in order to define nanoscale self-aligned semiconductor features; producing said gate on the surface of said self-aligned semiconductor features.