Abstract: A semiconductor device includes first and second second-conductivity-type region groups containing multiple second-conductivity-type regions that are disposed on a first silicon carbide semiconductor layer of a first conductivity type, arrayed in parallel following one direction with a space between each other, and first and second electrodes disposed on the first silicon carbide semiconductor layer and forming a Schottky junction with the first silicon carbide semiconductor layer. The first electrode covers a position where a distance from adjacent first and second second-conductivity-type regions included in a first second-conductivity-type region group, and a distance from a third second-conductivity-type region included in a second second-conductivity-type region group and adjacent to the first and second second-conductivity-type regions, are equal.

Abstract: A semiconductor device includes a silicon carbide semiconductor substrate, a silicon carbide layer, a switching element section, and an overvoltage detection element section whose area is smaller than that of the switching element section. The switching element section includes a first electrode pad, a first terminal section surrounding the first electrode pad and provided in the silicon carbide layer, and a first insulating film covering the first terminal section. The overvoltage detection element section includes a second electrode pad, a second terminal section surrounding the second electrode pad and provided in the silicon carbide layer, and a second insulating film covering the second terminal section and being in contact with the silicon carbide layer. A breakdown field strength of at least part of a portion of the second insulating film being in contact with the silicon carbide layer is lower than that of the first insulating film.

Abstract: A semiconductor device includes a first cell and a second cell. Each of the first cell and the second cell includes a first silicon carbide semiconductor layer including a first region and a second region provided in the first region, a second silicon carbide semiconductor layer provided on and in contact with the first silicon carbide semiconductor layer, a first ohmic electrode in ohmic contact with the second region, and an insulating film provided on the second silicon carbide semiconductor layer. The first cell includes a gate electrode, and the second cell includes no electrode configured to control the electric potential of the second silicon carbide semiconductor layer independently of the electric potential of the first ohmic electrode.

Abstract: This semiconductor device includes a silicon carbide layer of a first conductivity type having first and second principal surfaces and including an element region and a terminal region surrounding the element region on the first principal surface. The silicon carbide layer includes a first dopant layer of the first conductivity type contacting with the first principal surface and a second dopant layer of the first conductivity type located closer to the second principal surface than the first dopant layer is. The terminal region has, in its surface portion with a predetermined depth under the first principal surface, a terminal structure including respective portions of the first and second dopant layers and a ring region of a second conductivity type running through the first dopant layer to reach the second dopant layer. The dopant concentration of the first dopant layer is twice to five times as high as that of the second dopant layer 22.

Abstract: A semiconductor element including an MISFET exhibits diode characteristics in a reverse direction through an epitaxial channel layer. The semiconductor element includes: a silicon carbide semiconductor substrate of a first conductivity type, semiconductor layer of the first conductivity type, body region of a second conductivity type, source region of the first conductivity type, epitaxial channel layer in contact with the body region, source electrode, gate insulating film, gate electrode and drain electrode. If the voltage applied to the gate electrode is smaller than a threshold voltage, the semiconductor element functions as a diode wherein current flows from the source electrode to the drain electrode through the epitaxial channel layer. The absolute value of the turn-on voltage of this diode is smaller than the turn-on voltage of a body diode that is formed of the body region and the first silicon carbide semiconductor layer.

Abstract: In a semiconductor element, a body region of a second conductivity type includes a first body region in contact with a surface of a first silicon carbide semiconductor layer, and a second body region in contact with a bottom surface of the body region of the second conductivity type. The impurity concentration of the first body region is twice or more the impurity concentration of the second body region. A second silicon carbide semiconductor layer of a first conductivity type, which is a channel layer, has an impurity concentration distribution in a direction perpendicular to a semiconductor substrate, and an impurity concentration on a side in contact with the gate insulating film is lower than an impurity concentration on a side in contact with the first body region.

Abstract: This semiconductor device includes a silicon carbide layer of a first conductivity type having first and second principal surfaces and including an element region and a terminal region surrounding the element region on the first principal surface. The silicon carbide layer includes a first dopant layer of the first conductivity type contacting with the first principal surface and a second dopant layer of the first conductivity type located closer to the second principal surface than the first dopant layer is. The terminal region has, in its surface portion with a predetermined depth under the first principal surface, a terminal structure including respective portions of the first and second dopant layers and a ring region of a second conductivity type running through the first dopant layer to reach the second dopant layer. The dopant concentration of the first dopant layer is twice to five times as high as that of the second dopant layer 22.

Abstract: A method for fabricating a semiconductor element according to the present disclosure includes the steps of: (A) forming a first silicon carbide semiconductor layer of a first conductivity type on a semiconductor substrate; (B) forming a first mask to define a body region on the first silicon carbide semiconductor layer; (C) forming a body implanted region of a second conductivity type in the first silicon carbide semiconductor layer using the first mask; (D) forming a sidewall on side surfaces of the first mask; (E) defining a dopant implanted region of the first conductivity type and a first body implanted region of the second conductivity type in the first silicon carbide semiconductor layer using the first mask and the sidewall; and (F) thermally treating the first silicon carbide semiconductor layer.

Abstract: A semiconductor layer 102 having a drift region 132, a body region 103, and a source region 104 provided at a position next to the body region 103; an epitaxial layer 106 in contact with the body region; and a gate insulating film 107 provided on the epitaxial layer are formed on a principal surface of a semiconductor substrate 101. The epitaxial layer includes an interface epitaxial layer 106i in contact with the body region, a first epitaxial layer 106a on the interface epitaxial layer 106i, and a second epitaxial layer 106b on the first epitaxial layer 106a. An impurity concentration of the interface epitaxial layer is higher than an impurity concentration of the first epitaxial layer, and lower than an impurity concentration of the second epitaxial layer.

Abstract: In a semiconductor element, a body region of a second conductivity type includes a first body region in contact with a surface of a first silicon carbide semiconductor layer, and a second body region in contact with a bottom surface of the body region of the second conductivity type. The impurity concentration of the first body region is twice or more the impurity concentration of the second body region. A second silicon carbide semiconductor layer of a first conductivity type, which is a channel layer, has an impurity concentration distribution in a direction perpendicular to a semiconductor substrate, and an impurity concentration on a side in contact with the gate insulating film is lower than an impurity concentration on a side in contact with the first body region.

Abstract: A semiconductor device includes a first cell and a second cell. Each of the first cell and the second cell includes a first silicon carbide semiconductor layer including a first region and a second region provided in the first region, a second silicon carbide semiconductor layer provided on and in contact with the first silicon carbide semiconductor layer, a first ohmic electrode in ohmic contact with the second region, and an insulating film provided on the second silicon carbide semiconductor layer. The first cell includes a gate electrode, and the second cell includes no electrode configured to control the electric potential of the second silicon carbide semiconductor layer independently of the electric potential of the first ohmic electrode.

Abstract: A semiconductor element according to the present invention includes: a semiconductor substrate of a first conductivity type; a first silicon carbide semiconductor layer of the first conductivity type on the semiconductor substrate; a body region of a second conductivity type defined in the first silicon carbide semiconductor layer; an impurity region of the first conductivity type defined in the body region; a second silicon carbide semiconductor layer of the first conductivity type on the first silicon carbide semiconductor layer; a gate insulating film on the second silicon carbide semiconductor layer; a gate electrode on the gate insulating film; a first ohmic electrode connected to the impurity region; and a second ohmic electrode on the back surface of the semiconductor substrate. The body region includes first and second body regions. The average impurity concentration of the first body region is twice or more as high as that of the second body region.

Abstract: A semiconductor device disclosed in the present application includes: a semiconductor substrate; a first silicon carbide semiconductor layer located on a principal surface of the semiconductor substrate, the first silicon carbide semiconductor layer including a drift region of a first conductivity type, a body region of a second conductivity type, and an impurity region of a first conductivity type; a trench provided in the first silicon carbide semiconductor layer so as to reach inside of the drift region; a second silicon carbide semiconductor layer of the first conductivity type located at least on a side surface of the trench so as to be in contact with the impurity region and the drift region; a gate insulating film; a gate electrode; a first ohmic electrode; and a second ohmic electrode.

Abstract: A semiconductor layer 102 having a drift region 132, a body region 103, and a source region 104 provided at a position next to the body region 103; an epitaxial layer 106 in contact with the body region; and a gate insulating film 107 provided on the epitaxial layer are formed on a principal surface of a semiconductor substrate 101. The epitaxial layer includes an interface epitaxial layer 106i in contact with the body region, a first epitaxial layer 106a on the interface epitaxial layer 106i, and a second epitaxial layer 106b on the first epitaxial layer 106a. An impurity concentration of the interface epitaxial layer is higher than an impurity concentration of the first epitaxial layer, and lower than an impurity concentration of the second epitaxial layer.

Abstract: This silicon carbide semiconductor element includes: a body region of a second conductivity type which is located on a drift layer of a first conductivity type; an impurity region of the first conductivity type which is located on the body region; a trench which runs through the body region and the impurity region to reach the drift layer; a gate insulating film which is arranged on surfaces of the trench; and a gate electrode which is arranged on the gate insulating film. The surfaces of the trench include a first side surface and a second side surface which is opposed to the first side surface. The concentration of a dopant of the second conductivity type is higher at least locally in a portion of the body region which is located beside the first side surface than in another portion of the body region which is located beside the second side surface.

Abstract: This silicon carbide semiconductor element includes: a body region of a second conductivity type which is located on a drift layer of a first conductivity type; an impurity region of the first conductivity type which is located on the body region; a trench which runs through the body region and the impurity region to reach the drift layer; a gate insulating film which is arranged on surfaces of the trench; and a gate electrode which is arranged on the gate insulating film. The surfaces of the trench include a first side surface and a second side surface which is opposed to the first side surface. The concentration of a dopant of the second conductivity type is higher at least locally in a portion of the body region which is located beside the first side surface than in another portion of the body region which is located beside the second side surface.

Abstract: A semiconductor element including an MISFET exhibits diode characteristics in a reverse direction through an epitaxial channel layer. The semiconductor element includes: a silicon carbide semiconductor substrate of a first conductivity type, semiconductor layer of the first conductivity type, body region of a second conductivity type, source region of the first conductivity type, epitaxial channel layer in contact with the body region, source electrode, gate insulating film, gate electrode and drain electrode. If the voltage applied to the gate electrode is smaller than a threshold voltage, the semiconductor element functions as a diode wherein current flows from the source electrode to the drain electrode through the epitaxial channel layer. The absolute value of the turn-on voltage of this diode is smaller than the turn-on voltage of a body diode that is formed of the body region and the first silicon carbide semiconductor layer.

Abstract: A semiconductor element according to the present invention can perform both a transistor operation and a diode operation via its channel layer. If the potential Vgs of its gate electrode 165 with respect to that of its source electrode 150 is 0 volts, then a depletion layer with a thickness Dc, which has been depleted entirely in the thickness direction, is formed in at least a part of the channel layer 150 due to the presence of a pn junction between a portion of its body region 130 and the channel layer 150, and another depletion layer that has a thickness Db as measured from the junction surface of the pn junction is formed in that portion of the body region 130.

Abstract: A semiconductor device disclosed in the present application includes: a semiconductor substrate; a first silicon carbide semiconductor layer located on a principal surface of the semiconductor substrate, the first silicon carbide semiconductor layer including a drift region of a first conductivity type, a body region of a second conductivity type, and an impurity region of a first conductivity type; a trench provided in the first silicon carbide semiconductor layer so as to reach inside of the drift region; a second silicon carbide semiconductor layer of the first conductivity type located at least on a side surface of the trench so as to be in contact with the impurity region and the drift region; a gate insulating film; a gate electrode; a first ohmic electrode; and a second ohmic electrode.

Abstract: This silicon carbide semiconductor element includes: a body region of a second conductivity type which is located on a drift layer of a first conductivity type; an impurity region of the first conductivity type which is located on the body region; a trench which runs through the body region and the impurity region to reach the drift layer; a gate insulating film which is arranged on surfaces of the trench; and a gate electrode which is arranged on the gate insulating film. The surfaces of the trench include a first side surface and a second side surface which is opposed to the first side surface. The concentration of a dopant of the second conductivity type is higher at least locally in a portion of the body region which is located beside the first side surface than in another portion of the body region which is located beside the second side surface.