Abstract: A semiconductor device manufacturing method of an embodiment includes the steps of: forming a first insulating layer on a semiconductor substrate; forming on the first insulating layer an amorphous or polycrystalline semiconductor layer having a narrow portion; forming on the semiconductor layer a second insulating layer having a thermal expansion coefficient larger than that of the semiconductor layer; performing thermal treatment; removing the second insulating layer; forming a gate insulating film on the side faces of the narrow portion; forming a gate electrode on the gate insulating film; and forming a source-drain region in the semiconductor layer.

Abstract: A semiconductor device according to an embodiment includes: a polycrystalline semiconductor layer formed on an insulating film, the polycrystalline semiconductor layer including a first region and second and third regions each having a greater width than the first region, one of the second and third regions being connected to the first region; a gate insulating film formed at least on side faces of the first region of the polycrystalline semiconductor layer; a gate electrode formed on the gate insulating film; and gate sidewalls made of an insulating material, the gate sidewalls being formed on side faces of the gate electrode on sides of the second and third regions. Content of an impurity per unit volume in the first region is larger than content of the impurity per unit volume in the second and third regions.

Abstract: According to one embodiment, a semiconductor device includes a substrate and a first transistor. The substrate has a major surface. The first transistor is provided on the major surface. The first transistor includes a first stacked body, first and second conductive sections, a first gate electrode, and a first gate insulating film. The first stacked body includes first semiconductor layers and first insulating layers alternately stacked. The first semiconductor layers have a side surface. The first conductive section is electrically connected to one of the first semiconductor layers. The second conductive section is apart from the first conductive section and electrically connected to the one of the first semiconductor layers. The first gate electrode is provided between the first and second conductive sections and opposed to the side surface. The first gate insulating film is provided between the first gate electrode and the first semiconductor layers.

Abstract: A semiconductor device manufacturing method of an embodiment includes the steps of: forming a first insulating layer on a semiconductor substrate; forming on the first insulating layer an amorphous or polycrystalline semiconductor layer having a narrow portion; forming on the semiconductor layer a second insulating layer having a thermal expansion coefficient larger than that of the semiconductor layer; performing thermal treatment; removing the second insulating layer; forming a gate insulating film on the side faces of the narrow portion; forming a gate electrode on the gate insulating film; and forming a source-drain region in the semiconductor layer.

Abstract: A semiconductor device according to embodiments includes a semiconductor substrate, a buried insulating layer which is formed on the semiconductor substrate, a semiconductor layer which is formed on the buried insulating layer and includes a narrow portion and two wide portions which are larger than the narrow portion in width and are respectively connected to one end and the other end of the narrow portion, a gate insulating film which is formed on a side surface of the narrow portion, and a gate electrode formed on the gate insulating film. The impurity concentration of the semiconductor substrate directly below the narrow portion is higher than the impurity concentration of the narrow portion, and the impurity concentration of the semiconductor substrate directly below the narrow portion is higher than the impurity concentration of the semiconductor substrate directly below the wide portion.

Abstract: A semiconductor device according to an embodiment includes: first and second semiconductor regions each having a protruded shape provided on a substrate, the first semiconductor region including a first source, a first drain, and a first channel provided between the first source and the first drain and extending in a first direction from the first source to the first drain, the first channel having a first width in a second direction perpendicular to the first direction, and the second semiconductor region including a second source, a second drain, and a second channel provided between the second source and the second drain and extending in a third direction from the second source to the second drain, the second channel having a second width in a fourth direction perpendicular to the third direction that is wider than the first width of the first channel.

Abstract: A semiconductor device of an embodiment includes: a first transistor having a first source region and a first drain region arranged in a first protruded semiconductor region, a first channel region having a first corner portion in its upper portion in a section perpendicular to a first direction, the first corner portion having a first radius of curvature; a second transistor having a second source region and a second drain region arranged in a second protruded semiconductor region, and a second channel region having a second corner portion in its upper portion in a section that is perpendicular to a second direction, the second corner portion having a second radius of curvature greater than the first radius of curvature.

Abstract: According to one embodiment, a semiconductor device includes a fin type stacked layer structure which has first to third semiconductor layers, and first to third layer select transistors to select one of the first to third semiconductor layers. The second layer select transistor is normally on in the second semiconductor layer, and is controlled to be on or off in the first and third semiconductor layers. A channel region of the second semiconductor layer which is covered with a gate electrode of the second layer select transistor has a metal silicide.

Abstract: A method of manufacturing a semiconductor device according to an embodiment includes: forming a plurality of semiconductor layers located at a distance from one another on a first insulating film; forming a gate insulating film that covers both side faces and an upper face of each of the semiconductor layers; forming a gate electrode of a polysilicon film to cover the gate insulating film of each of the semiconductor layers; forming a second insulating film on an entire surface; exposing an upper face of the gate electrode by performing selective etching on a portion of the second insulating film; siliciding the gate electrode; and forming a stress applying film that applies a stress in a direction perpendicular to the extending direction of each of the semiconductor layers and parallel to an upper face of the first insulating film.

Abstract: A semiconductor device of an embodiment includes: an insulating film including: a first region extending in a first direction; second and third regions arranged at a distance from each other; and fourth and fifth regions each having a concave shape, the fourth and fifth regions each having a smaller film thickness than a film thickness of each of the first through third regions; a semiconductor layer formed in a direction from the fourth region toward the fifth region, the semiconductor layer having a smaller width than a width of each of source and drain regions, the semiconductor layer being connected to the source and drain regions; a gate electrode placed on the opposite side of a gate insulating film from the semiconductor layer on the first region; and a gate sidewall formed on a side face of the gate electrode.

Abstract: A semiconductor device according to embodiments includes a semiconductor substrate, a buried insulating layer which is formed on the semiconductor substrate, a semiconductor layer which is formed on the buried insulating layer and includes a narrow portion and two wide portions which are larger than the narrow portion in width and are respectively connected to one end and the other end of the narrow portion, a gate insulating film which is formed on a side surface of the narrow portion, and a gate electrode formed on the gate insulating film. The impurity concentration of the semiconductor substrate directly below the narrow portion is higher than the impurity concentration of the narrow portion, and the impurity concentration of the semiconductor substrate directly below the narrow portion is higher than the impurity concentration of the semiconductor substrate directly below the wide portion.

Abstract: A semiconductor device of an embodiment includes: an insulating film including: a first region extending in a first direction; second and third regions arranged at a distance from each other; and fourth and fifth regions each having a concave shape, the fourth and fifth regions each having a smaller film thickness than a film thickness of each of the first through third regions; a semiconductor layer formed in a direction from the fourth region toward the fifth region, the semiconductor layer having a smaller width than a width of each of source and drain regions, the semiconductor layer being connected to the source and drain regions; a gate electrode placed on the opposite side of a gate insulating film from the semiconductor layer on the first region; and a gate sidewall formed on a side face of the gate electrode.

Abstract: In a semiconductor device manufacturing method, a first semiconductor region which includes a narrow portion and a wide portion is formed in an upper portion of a semiconductor substrate, a gate insulating film is formed on at least side surfaces of the narrow portion, a gate electrode is formed on the gate insulating film, a mask pattern that covers the wide portion is formed, ion implantation of an impurity is performed with the mask pattern as a mask to form an extension impurity region in the narrow portion, the mask pattern is removed, a heat treatment is performed to activate the impurity, a gate sidewall is formed on a side surface of the gate electrode, epitaxial growth of a semiconductor film is performed on the narrow portion and the wide portion after the formation of the gate sidewall, and source-drain regions is formed on both sides of the gate electrode.

Abstract: A semiconductor device of an embodiment includes: an insulating film including: a first region extending in a first direction; second and third regions arranged at a distance from each other; and fourth and fifth regions each having a concave shape, the fourth and fifth regions each having a smaller film thickness than a film thickness of each of the first through third regions; a semiconductor layer formed in a direction from the fourth region toward the fifth region, the semiconductor layer having a smaller width than a width of each of source and drain regions, the semiconductor layer being connected to the source and drain regions; a gate electrode placed on the opposite side of a gate insulating film from the semiconductor layer on the first region; and a gate sidewall formed on a side face of the gate electrode.

Abstract: In a semiconductor device manufacturing method, a first semiconductor region which includes a narrow portion and a wide portion is formed in an upper portion of a semiconductor substrate, a gate insulating film is formed on at least side surfaces of the narrow portion, a gate electrode is formed on the gate insulating film, a mask pattern that covers the wide portion is formed, ion implantation of an impurity is performed with the mask pattern as a mask to form an extension impurity region in the narrow portion, the mask pattern is removed, a heat treatment is performed to activate the impurity, a gate sidewall is formed on a side surface of the gate electrode, epitaxial growth of a semiconductor film is performed on the narrow portion and the wide portion after the formation of the gate sidewall, and source-drain regions is formed on both sides of the gate electrode.

Abstract: According to one embodiment, a semiconductor device includes a fin type stacked layer structure which has first to third semiconductor layers, and first to third layer select transistors to select one of the first to third semiconductor layers. The second layer select transistor is normally on in the second semiconductor layer, and is controlled to be on or off in the first and third semiconductor layers. A channel region of the second semiconductor layer which is covered with a gate electrode of the second layer select transistor has a metal silicide.

Abstract: A field effect transistor according to an embodiment includes: a semiconductor layer; a source region and a drain region formed at a distance from each other in the semiconductor layer; a gate insulating film formed on a portion of the semiconductor layer, the portion being located between the source region and the drain region; a gate electrode formed on the gate insulating film; and a gate sidewall formed on at least one of side faces of the gate electrode, the side faces being located on a side of the source region and on a side of the drain region, the gate sidewall being made of a high dielectric material. The source region and the drain region are separately-placed from the corresponding side faces of the gate electrode.

Abstract: A semiconductor device according to an embodiment includes: a polycrystalline semiconductor layer formed on an insulating film, the polycrystalline semiconductor layer including a first region and second and third regions each having a greater width than the first region, one of the second and third regions being connected to the first region; a gate insulating film formed at least on side faces of the first region of the polycrystalline semiconductor layer; a gate electrode formed on the gate insulating film; and gate sidewalls made of an insulating material, the gate sidewalls being formed on side faces of the gate electrode on sides of the second and third regions. Content of an impurity per unit volume in the first region is larger than content of the impurity per unit volume in the second and third regions.

Abstract: A semiconductor device according to an embodiment includes a semiconductor substrate, a gate insulating film formed on the semiconductor substrate, a gate electrode formed on the gate insulating film, first gate sidewalls formed on both sides of the gate electrode, and a source/drain semiconductor layer formed on the semiconductor substrate to sandwich the first gate sidewalls with the gate electrode. Further, second gate sidewalls are provided on the first gate sidewalls and the source/drain semiconductor layer at both sides of the gate electrode, wherein the boundary of each of the second gate sidewalls with each of the first gate sidewalls is terminated at the side surface of the gate electrode, and each of the second gate sidewalls has a smaller Young's modulus and a lower dielectric constant than each of the first gate sidewalls.

Abstract: A method of manufacturing a semiconductor device according to an embodiment includes: forming a plurality of semiconductor layers located at a distance from one another on a first insulating film; forming a gate insulating film that covers both side faces and an upper face of each of the semiconductor layers; forming a gate electrode of a polysilicon film to cover the gate insulating film of each of the semiconductor layers; forming a second insulating film on an entire surface; exposing an upper face of the gate electrode by performing selective etching on a portion of the second insulating film; siliciding the gate electrode; and forming a stress applying film that applies a stress in a direction perpendicular to the extending direction of each of the semiconductor layers and parallel to an upper face of the first insulating film.