A semiconductor device includes an IGBT region with a bottom-body region on a front surface side of an IGBT drift region, an IGBT barrier region on a front surface side of the bottom-body region, and a top-body region on a front surface side of the IGBT barrier region. A diode region is include with a bottom-anode region on a front surface side of the diode drift region, a diode barrier region on a front surface side of the bottom-anode region, a top-anode region on a front surface side of the diode barrier region, and a pillar region extending from the front surface of the semiconductor substrate, piercing the top-anode region, and reaching the diode barrier region, and connected to the front surface electrode and the diode barrier region. An impurity concentration of the top-body region is lower than an impurity concentration of the bottom-anode region.

There is provided a high withstand voltage LDMOS field-effect transistor that enables the compatibility of an increase of its withstand voltage and a decrease of its ON resistance. The high withstand voltage LDMOS is characterizing in including: a first electroconductive type body region formed on a main surface of a semiconductor substrate; a second electroconductive type source region formed on a surface of the body region; a second electroconductive type drift region formed so as to have contact with the body region; a second electroconductive type drain region formed on the drift region; a first electroconductive type buried region having contact with the body region and formed below the drift region; a gate electrode formed above the body region between the source region and the drift region and above the drift region nearer to the source region via a gate insulating film; a first field plate that extends from the gate electrode toward the drain region and that is formed above the drift region via a first insulating film; and a second field plate that has contact with the source region or the gate electrode and that is formed above the first field plate via a second insulating film, in which a distance between the buried region and the drain region is smaller than a distance between the first field plate and the drain region and larger than a distance between the second field plate and the drain region.

An integrated circuit device includes: a substrate including a first surface and a second surface that is opposite to the first surface; and a diode structure including: an upper semiconductor layer disposed on the first surface of the substrate and including a first dopant of a first conductivity type; a lower semiconductor layer disposed on the second surface of the substrate and including a second dopant of a second conductivity type that is different from the first conductivity type; and a first well region provided in a portion of the substrate that is between the upper semiconductor layer and the lower semiconductor layer, wherein the first well region is in contact with the upper semiconductor layer or the lower semiconductor layer.

The invention provides a semiconductor device, including a buried oxide layer disposed on a substrate. A semiconductor layer is disposed on the buried oxide layer. A first well is disposed in the semiconductor layer. A second well and a third well are disposed to opposite sides of the first well and separated from the first well. An isolation feature covers the first well and the third well. A poly field plate is disposed on the isolation feature and over the semiconductor layer between the first well and the third well. A first anode doped region is disposed on the second well. A second anode doped region and a third anode doped region are disposed on the second well. The second anode doped region is positioned directly on the third anode doped region. A first cathode doped region is coupled to the third well.

A power semiconductor device includes: a substrate; an anode electrode and a cathode electrode disposed on the substrate; a well region disposed inside the substrate in a lower portion of the anode electrode, and having p-type conductivity; an NISO region disposed in a lower portion of the well region inside the substrate, and having a first n-type impurity concentration; and an n-type buried layer disposed in a lower portion of the NISO region, and having a second impurity concentration greater than the first n-type impurity concentration, inside the substrate.

Impurity elements are doped at a high concentration exceeding a thermodynamic equilibrium concentration into a solid material having an extremely small diffusion coefficient of the impurity element. A method for doping impurities includes steps for depositing source film made of material containing impurity elements with a film thickness on a surface of a solid target object (semiconductor substrate) made from the solid material. The film thickness is determined in consideration of irradiation time per light pulse and the energy density of the light pulse. The method also includes a step for irradiating the source film by the light pulse with the irradiation time and the energy density so as to dope the impurity elements into the target object at a concentration exceeding a thermodynamic equilibrium concentration.

An influence of a gate interference is suppressed and a reverse recovery property of a diode is improved. A diode includes a diode region located between the first boundary trench and the second boundary trench and a first and second IGBT regions. An emitter region and a body region are provided in each of the first and second IGBT regions. Each body region includes a body contact portion. An anode region is provided in the diode region. The anode region includes an anode contact portion. An interval between the first and second boundary trenches is equal to or longer than 200 m. An area ratio of the anode contact portion in the diode region is lower than each of an area ratio of the body contact portion in the first IGBT region and an area ratio of the body contact portion in the second IGBT region.

A semiconductor device is disclosed. In a surface layer of a front surface of an n-type semiconductor substrate, an anode layer is provided in an element activation portion and an annular p-type guard ring and an n-type high-concentration surface region are provided in an annular termination breakdown voltage region which surrounds the outer circumference of the anode layer. The impurity concentration of the n-type high-concentration surface region is higher than that of the semiconductor substrate and is lower than that of the p-type guard ring. The depth of the n-type high-concentration surface region is less than that of the guard ring. The anode layer and the guard ring are formed while the oxygen concentration of the semiconductor substrate is set to be equal to or more than 110.sup.16/cm.sup.3 and equal to or less than 110.sup.18/cm.sup.3.

The invention provides a semiconductor device. The semiconductor device includes a buried oxide layer disposed on a substrate. A semiconductor layer having a first conduction type is disposed on the buried oxide layer. A first well doped region having a second conduction type is disposed in the semiconductor layer. A cathode doped region having the second conduction type is disposed in the first well doped region. A first anode doped region having the first conduction type is disposed in the first well doped region, separated from the cathode doped region. A first distance from a bottom boundary of the first anode doped region to a top surface of the semiconductor layer is greater than a second distance from the bottom boundary to an interface between the semiconductor layer and the buried oxide layer.

A diode includes a semiconductor substrate having a surface; a first contact region disposed at the surface of the semiconductor substrate and having a first conductivity type; and a second contact region disposed at the surface, laterally spaced from the first contact region, and having a second conductivity type. The diode also includes a buried region disposed in the semiconductor substrate vertically adjacent to the first contact region, having the second conductivity type, and electrically connected with the second contact region; and an isolation region disposed at the surface between the first and second contact regions. The diode also includes a separation region disposed at the surface between the first contact region and the isolation region, the separation region formed from a portion of a first well region disposed in the semiconductor substrate that extends to the surface.