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: The semiconductor chip (18) of the present invention is a semiconductor chip (18) on which a power semiconductor device (10) is formed, and which includes a semiconductor substrate made from a hexagonal semiconductor, in which the semiconductor substrate has a shape of a rectangle on a principal surface, in which the rectangle is defined by two sides having lengths a and b equal to each other, and in which linear expansion coefficients in directions parallel to the two sides of the semiconductor substrate are equal to each other.

Abstract: As viewed along a normal to the principal surface of a substrate 101, this semiconductor element 100 has a unit cell region 100ul and a terminal region 100f located between the unit cell region and an edge of the semiconductor element. The terminal region 100f includes a ring region 103f of a second conductivity type which is arranged in a first silicon carbide semiconductor layer 102 so as to contact with a drift region 102d. The ring region includes a high concentration ring region 103af which contacts with the surface of the first silicon carbide semiconductor layer and a low concentration ring region 103bf which contains an impurity of the second conductivity type at a lower concentration than in the high concentration ring region and of which the bottom contacts with the first silicon carbide semiconductor layer. A side surface of the high concentration ring region 103af contacts with the drift region 102d.

Abstract: As viewed along a normal to the principal surface of a substrate 101, this semiconductor element 100 has a unit cell region 100ul and a terminal region 100f located between the unit cell region and an edge of the semiconductor element. The terminal region 100f includes a ring region 103f of a second conductivity type which is arranged in a first silicon carbide semiconductor layer 102 so as to contact with a drift region 102d. The ring region includes a high concentration ring region 103af which contacts with the surface of the first silicon carbide semiconductor layer and a low concentration ring region 103bf which contains an impurity of the second conductivity type at a lower concentration than in the high concentration ring region and of which the bottom contacts with the first silicon carbide semiconductor layer. A side surface of the high concentration ring region 103af contacts with the drift region 102d.

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 100 including an MISFET according to the present invention is characterized by having diode characteristics in a reverse direction through an epitaxial channel layer 50. The semiconductor element 100 includes a silicon carbide semiconductor substrate 10 of a first conductivity type, a semiconductor layer 20 of the first conductivity type, a body region 30 of a second conductivity type, a source region 40 of the first conductivity type, an epitaxial channel layer 50 in contact with the body region, a source electrode 45, a gate insulating film 60, a gate electrode 65 and a drain electrode 70. If the voltage applied to the gate electrode of the MISFET is smaller than a threshold voltage, the semiconductor element 100 functions as a diode in which current flows from the source electrode 45 to the drain electrode 70 through the epitaxial channel layer 50.

Abstract: A semiconductor chip of the present invention is a semiconductor device that includes a hexagonal semiconductor layer having anisotropic mechanical properties. A semiconductor chip (21), when viewed from a direction perpendicular to the semiconductor chip (21), has a rectangular shape that has a first side (1A) and a second side (1B) orthogonal to the first side (1A). The amount of thermal deformation along a direction in which the first side (1A) extends and the amount of thermal deformation along a direction in which the second side (1B) extends are substantially equal to each other.

Abstract: The semiconductor chip (18) of the present invention is a semiconductor chip (18) on which a power semiconductor device (10) is formed, and which includes a semiconductor substrate made from a hexagonal semiconductor, in which the semiconductor substrate has a shape of a rectangle on a principal surface, in which the rectangle is defined by two sides having lengths a and b equal to each other, and in which linear expansion coefficients in directions parallel to the two sides of the semiconductor substrate are equal to each other.

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 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 element 100 including an MISFET according to the present invention is characterized by having diode characteristics in a reverse direction through an epitaxial channel layer 50. The semiconductor element 100 includes a semiconductor layer 20 of a first conductivity type, a body region 30 of a second conductivity type, source and drain regions 40 and 75 of the first conductivity type, an epitaxial channel layer 50 in contact with the body region, source and drain electrodes 45 and 70, a gate insulating film 60, and a gate electrode 65. If the voltage applied to the gate electrode of the MISFET is smaller than a threshold voltage, the semiconductor element 100 functions as a diode in which current flows from the source electrode 45 to the drain electrode 70 through the epitaxial channel layer 50. The absolute value of the turn-on voltage of this diode is smaller than that of 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 device according to the present invention includes: a silicon carbide substrate (11) that has a principal surface and a back surface; a semiconductor layer (12), which has been formed on the principal surface of the silicon carbide substrate; and a back surface ohmic electrode layer (1d), which has been formed on the back surface of the silicon carbide substrate. The back surface ohmic electrode layer (1d) includes: a reaction layer (1da), which is located closer to the back surface of the silicon carbide substrate and which includes titanium, silicon and carbon; and a titanium nitride layer (1db), which is located more distant from the back surface of the silicon carbide substrate.

Abstract: A method of producing a semiconductor device according to the present invention includes: a step of implanting an impurity into a semiconductor layer 2 by using a first implantation mask layer 30, thereby forming a body region 6; a step of implanting an impurity by using the first implantation mask layer 30 and a second implantation mask layer 31, thereby forming a contact region 7 within the body region 6; a step of forming a third implantation mask layer 32, and thereafter selectively removing the second implantation mask layer 31; a step of forming a side wall 34 on a side face of the first implantation mask layer 30; and a step of implanting an impurity to form a source region 8 within the body region 6.

Abstract: A semiconductor device 100 includes: a silicon carbide layer 102; a source region 104 of a first conductivity type disposed in the silicon carbide layer; a body region 103 of a second conductivity type disposed at a position in contact with the source region 104 in the silicon carbide layer; a contact region 105 of the second conductivity type formed in the body region; a drift region 102d of the first conductivity type disposed in the silicon carbide layer; and a source electrode 109 in ohmic contact with the source region 104 and the contact region 105, wherein: a side wall of the source electrode 109 is in contact with the source region 104; a lower surface of the source electrode 109 is in contact with the contact region 105 and is not in contact with the source region 104; and at least a portion of the source region 104 overlaps the contact region 105 as viewed from a direction perpendicular to a principle surface of a substrate 101.

Abstract: A semiconductor chip of the present invention is a semiconductor device that includes a hexagonal semiconductor layer having anisotropic mechanical properties. A semiconductor chip (21), when viewed from a direction perpendicular to the semiconductor chip (21), has a rectangular shape that has a first side (1A) and a second side (1B) orthogonal to the first side (1A). The amount of thermal deformation along a direction in which the first side (1A) extends and the amount of thermal deformation along a direction in which the second side (1B) extends are substantially equal to each other.

Abstract: A semiconductor element 100 including an MISFET according to the present invention is characterized by having diode characteristics in a reverse direction through an epitaxial channel layer 50. The semiconductor element 100 includes a semiconductor layer 20 of a first conductivity type, a body region 30 of a second conductivity type, source and drain regions 40 and 75 of the first conductivity type, an epitaxial channel layer 50 in contact with the body region, source and drain electrodes 45 and 70, a gate insulating film 60, and a gate electrode 65. If the voltage applied to the gate electrode of the MISFET is smaller than a threshold voltage, the semiconductor element 100 functions as a diode in which current flows from the source electrode 45 to the drain electrode 70 through the epitaxial channel layer 50. The absolute value of the turn-on voltage of this diode is smaller than that of 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 100 including an MISFET according to the present invention is characterized by having diode characteristics in a reverse direction through an epitaxial channel layer 50. The semiconductor element 100 includes a silicon carbide semiconductor substrate 10 of a first conductivity type, a semiconductor layer 20 of the first conductivity type, a body region 30 of a second conductivity type, a source region 40 of the first conductivity type, an epitaxial channel layer 50 in contact with the body region, a source electrode 45, a gate insulating film 60, a gate electrode 65 and a drain electrode 70. If the voltage applied to the gate electrode of the MISFET is smaller than a threshold voltage, the semiconductor element 100 functions as a diode in which current flows from the source electrode 45 to the drain electrode 70 through the epitaxial channel layer 50.

Abstract: A semiconductor device includes: a semiconductor layer including silicon carbide, which has been formed on a substrate; a semiconductor region 15 of a first conductivity type defined on the surface of the semiconductor layer 10; a semiconductor region 14 of a second conductivity type, which is defined on the surface 10s of the semiconductor layer so as to surround the semiconductor region 15 of the first conductivity type; and a conductor 19 with a conductive surface 19s that contacts with the semiconductor regions 15 and 14 of the first and second conductivity types. On the surface 10s of the semiconductor layer, the semiconductor region 15 of the first conductivity type has at least one first strip portion 60 that runs along a first axis i. The width C1 of the semiconductor region 15 of the first conductivity type as measured along the first axis i is greater than the width A1 of the conductive surface 19s as measured along the first axis i.

Abstract: A semiconductor device is fabricated on an off-cut semiconductor substrate 11. Each unit cell 10 thereof includes: a first semiconductor layer 12 on the surface of the substrate 11; a second semiconductor layer 16 stacked on the first semiconductor layer 12 to have an opening 16e that exposes first and second conductive regions 15 and 14 at least partially; a first conductor 19 located inside the opening 16e of the second semiconductor layer 16 and having a conductive surface 19s that contacts with the first and second conductive regions 15 and 14; and a second conductor 17 arranged on the second semiconductor layer 16 and having an opening 18e corresponding to the opening 16s of the second semiconductor layer 16.

Abstract: A semiconductor device includes: a semiconductor layer 10; a semiconductor region 15s of a first conductivity type defined on the surface 10s of the semiconductor layer; a semiconductor region 14s of a second conductivity type defined on the surface 10s of the semiconductor layer to surround the semiconductor region 15s; and a conductor 19 with a conductive surface 19s to contact with the semiconductor regions 15s and 14s. The semiconductor layer 10 includes silicon carbide. At least one of the semiconductor region 15s and the conductive surface 19s is not circular. The semiconductor region 15s and the conductive surface 19s are shaped such that as the degree of misalignment between the conductive surface 19s and the semiconductor region 15s increases from zero through one-third of the width of the conductive surface 19s, a portion of the profile of the conductive surface 19s that crosses the semiconductor region 15s has smoothly changing lengths.