Abstract: A semiconductor device according to an embodiment includes: a substrate; a first semiconductor layer formed on the substrate and having a strain; a second and a third semiconductor layers formed at a distance from each other on the first semiconductor layer, and having a different lattice constant from a lattice constant of the first semiconductor layer; a gate insulating film formed on a first portion of the first semiconductor layer, the first portion being located between the second semiconductor layer and the third semiconductor layer; and a gate electrode formed on the gate insulating film.

Abstract: A semiconductor device includes an NMISFET region. The NMISFET region includes a Ge nano wire having a triangular cross section along a direction perpendicular to a channel current direction, wherein two of surfaces that define the triangular cross section of the Ge nano wire are (111) planes, and the other surface that define the triangular cross section of the Ge nano wire is a (100) plane; and an Si layer or an Si1-xGex layer (0<x<0.5) on the (100) plane of the Ge nano wire.

Abstract: According to one embodiment, a semiconductor device including a tunnel FET, includes a gate electrode, which is formed on a first semiconductor layer formed of Si1-XGeX (0<x?1) through a gate insulating film, a source electrode, which is formed of a compound of a second semiconductor formed mainly using Ge and a metal, a drain electrode, which is formed of a compound of the first semiconductor layer and the metal, and a silicon (Si) thin film, which is formed between the source electrode and the first semiconductor layer. An edge portion of the source electrode and an edge portion of the drain electrode have a positional relationship of Asymmetrical to the gate electrode. The edge portion of the drain electrode is far away from an edge portion of the gate electrode toward a gate external direction compared with the edge portion of the source electrode.

Abstract: According to one embodiment, a semiconductor device having a Ge- or SiGe-fin structure includes a convex-shaped active area formed along one direction on the surface region of a Si substrate, a buffer layer of Si1-xGex (0<x<1) formed on the active area, and a fin structure of Si1-yGey (x<y?1) formed on the buffer layer. The fin structure has a side surface of a (110) plane perpendicular to the surface of the Si substrate and the width thereof in a direction perpendicular to the one direction of the fin structure is narrower than that of the buffer layer.

Abstract: A semiconductor device includes a Si substrate, an insulating film formed on one part of the Si substrate, a bulk Si region grown on other part of the Si substrate other than the insulating film, Si1-xGex(0<x?1) thin film formed on the insulating film in direct contact with the insulating film, and substantially flush with top of the bulk Si region, a first field effect transistor fabricated in the bulk Si region, and a second field effect transistor fabricated in the Si1-xGex thin film.

Abstract: A method for manufacturing a field effect transistor, includes: forming a mask of an insulating film on a semiconductor layer containing Si formed on a semiconductor substrate; forming the semiconductor layer into a mesa structure by performing etching with the use of the mask, the mesa structure extending in a direction parallel to an upper face of the semiconductor substrate; narrowing a distance between two sidewalls of the mesa structure and flattening the sidewalls by performing a heat treatment in a hydrogen atmosphere, the two sidewalls extending in the direction and facing each other; forming a gate insulating film covering the mesa structure having the sidewalls flattened; forming a gate electrode covering the gate insulating film; and forming source and drain regions at portions of the mesa structure, the portions being located on two sides of the gate electrode.

Abstract: A method for manufacturing a field effect transistor, includes: forming a mask of an insulating film on a semiconductor layer containing Si formed on a semiconductor substrate; forming the semiconductor layer into a mesa structure by performing etching with the use of the mask, the mesa structure extending in a direction parallel to an upper face of the semiconductor substrate; narrowing a distance between two sidewalls of the mesa structure and flattening the sidewalls by performing a heat treatment in a hydrogen atmosphere, the two sidewalls extending in the direction and facing each other; forming a gate insulating film covering the mesa structure having the sidewalls flattened; forming a gate electrode covering the gate insulating film; and forming source and drain regions at portions of the mesa structure, the portions being located on two sides of the gate electrode.

Abstract: A method for manufacturing a field effect transistor, includes: forming a mask of an insulating film on a semiconductor layer containing Si formed on a semiconductor substrate; forming the semiconductor layer into a mesa structure by performing etching with the use of the mask, the mesa structure extending in a direction parallel to an upper face of the semiconductor substrate; narrowing a distance between two sidewalls of the mesa structure and flattening the sidewalls by performing a heat treatment in a hydrogen atmosphere, the two sidewalls extending in the direction and facing each other; forming a gate insulating film covering the mesa structure having the sidewalls flattened; forming a gate electrode covering the gate insulating film; and forming source and drain regions at portions of the mesa structure, the portions being located on two sides of the gate electrode.

Abstract: A field effect transistor of an embodiment of the present invention includes, a semiconductor substrate containing Si atoms; a protruding structure formed on the semiconductor substrate; a channel region formed in the protruding structure and containing Ge atoms; an under channel region formed under the channel region in the protruding structure and containing Si and Ge atoms, the Ge composition ratio among Si and Ge atoms contained in the under channel region continuously changing from the channel region side to the semiconductor substrate side; a gate insulating film formed on the channel region; and a gate electrode formed on the gate insulating film on the channel region.

Abstract: A semiconductor device includes an NMISFET region. The NMISFET region includes a Ge nano wire having a triangular cross section along a direction perpendicular to a channel current direction, wherein two of surfaces that define the triangular cross section of the Ge nano wire are (111) planes, and the other surface that define the triangular cross section of the Ge nano wire is a (100) plane; and an Si layer or an Si1-xGex layer (0<x<0.5) on the (100) plane of the Ge nano wire.

Abstract: A method of manufacturing a semiconductor device. In the method, a substrate is prepared, which includes a buried oxide film and a SiGe layer formed on the buried oxide film. Then, heat treatment is performed on the substrate at a temperature equal to or lower than a first temperature, to form a protective oxide film on a surface of the SiGe layer. Next, the substrate having the protective oxide film is heated in a non-oxidizing atmosphere to a second temperature higher than the first temperature. Further, heat treatment is performed on the substrate thus heated, in an oxidizing atmosphere at a temperature equal to or higher than the second temperature, to form oxide the SiGe layer, make the SiGe layer thinner and increasing Ge concentration in the SiGe layer, thus forming a SiGe layer having the increased Ge concentration.

Abstract: A semiconductor device includes a Si substrate, an insulating film formed on one part of the Si substrate, a bulk Si region grown on other part of the Si substrate other than the insulating film, Si1-xGex (0<x?1) thin film formed on the insulating film in direct contact with the insulating film, and substantially flush with top of the bulk Si region, a first field effect transistor fabricated in the bulk Si region, and a second field effect transistor fabricated in the Si1-xGex thin film.

Abstract: A field effect transistor of an embodiment of the present invention includes, a semiconductor substrate containing Si atoms; a protruding structure formed on the semiconductor substrate; a channel region formed in the protruding structure and containing Ge atoms; an under channel region formed under the channel region in the protruding structure and containing Si and Ge atoms, the Ge composition ratio among Si and Ge atoms contained in the under channel region continuously changing from the channel region side to the semiconductor substrate side; a gate insulating film formed on the channel region; and a gate electrode formed on the gate insulating film on the channel region.

Abstract: A semiconductor device includes a Si substrate, an insulating film formed on onepart of the Si substrate, a bulk Si region grown on other part of the Si substrate other than the insulating film, Si1-xGex (0<x?1) thin film formed on the insulating film in direct contact with the insulating film, and substantially flush with top of the bulk Si region, a first field effect transistor fabricated in the bulk Si region, and a second field effect transistor fabricated in the Si1-xGex thin film.

Abstract: A field effect transistor comprises a source and a drain, and a channel layer of Si1-x-yGexCy crystal (1>x>0, 1>y?0). Ge composition increases toward a drain end, in a vicinity of a source end of the channel layer.

Abstract: A semiconductor device includes an n-channel MIS transistor and a p-channel MIS transistor on a semiconductor layer formed on an insulating layer, in which the channel of the n-channel MIS transistor is formed of a strained Si layer having biaxial tensile strain and the channel of the p-channel MIS transistor is formed of a strained SiGe layer having uniaxial compression strain in the channel length direction.

Abstract: A substrate used for fabricating devices thereon includes an insulating film, and a monocrystal Ge thin layer formed on the insulating film in contact therewith, the monocrystal Ge thin layer having a thickness not more than 6 nm. The monocrystal Ge thin layer has a thickness not less than 2 nm and a compressive strain.

Abstract: A method for manufacturing a field effect transistor, includes: forming a mask of an insulating film on a semiconductor layer containing Si formed on a semiconductor substrate; forming the semiconductor layer into a mesa structure by performing etching with the use of the mask, the mesa structure extending in a direction parallel to an upper face of the semiconductor substrate; narrowing a distance between two sidewalls of the mesa structure and flattening the sidewalls by performing a heat treatment in a hydrogen atmosphere, the two sidewalls extending in the direction and facing each other; forming a gate insulating film covering the mesa structure having the sidewalls flattened; forming a gate electrode covering the gate insulating film; and forming source and drain regions at portions of the mesa structure, the portions being located on two sides of the gate electrode.

Abstract: A field effect transistor of an embodiment of the present invention includes, a semiconductor substrate containing Si atoms; a protruding structure formed on the semiconductor substrate; a channel region formed in the protruding structure and containing Ge atoms; an under channel region formed under the channel region in the protruding structure and containing Si and Ge atoms, the Ge composition ratio among Si and Ge atoms contained in the under channel region continuously changing from the channel region side to the semiconductor substrate side; a gate insulating film formed on the channel region; and a gate electrode formed on the gate insulating film on the channel region.

Abstract: A field effect transistor fabricated in a device isolation region includes a Si1-xGex layer (0<x?1) that a lattice strain is relaxed, a strained Si layer formed on the Si1-xGex, a gate electrode insulatively disposed over a part of the strained Si layer, source and drain regions formed in the strained Si layer with the gate electrode being arranged between the source and drain regions; and a Si film covering side walls of the Si1-xGex layer on ends of the device isolation region.