Toyota Jidosha Kabushiki Kaisha

Kabushiki Kaisha Toyota Chuo Kenkyusho

Satoru Machida

Yusuke Yamashita

Jun Saito

Masaru Senoo

Yasuhiro Hirabayashi

Jun Okawara

Akitaka Soeno

Hiroshi Hosokawa

Takahide Sugiyama

Yoshifumi Yasuda

Koichi Nishikawa

Takashi Kuno

Disclosed is a technique capable of reducing loss at the time of switching in a diode. A diode disclosed in the present specification includes a cathode electrode, a cathode region made of a first conductivity type semiconductor, a drift region made of a low concentration first conductivity type semiconductor, an anode region made of a second conductivity type semiconductor, an anode electrode made of metal, a barrier region formed between the drift region and the anode region and made of a first conductivity type semiconductor having a concentration higher than that of the drift region, and a pillar region formed so as to connect the barrier region to the anode electrode and made of a first conductivity type semiconductor having a concentration higher than that of the barrier region. The pillar region and the anode are connected through a Schottky junction.

Diode, semiconductor device, and MOSFET

A semiconductor device includes a diode region and an IGBT region. The diode region includes a front side anode region, an n-type diode barrier region, an n-type diode pillar region reaching the diode barrier region through the front side anode region, and a p-type back side anode region separated from the front side anode region by the diode barrier region. The IGBT region includes a front side body region, an n-type IGBT barrier region, and a back side body region separated from the front side body region by the IGBT barrier region. When a gate-off voltage is applied to a gate electrode, a resistance between the IGBT barrier region and the emitter electrode is higher than a resistance between the diode barrier region and the anode electrode.

Semiconductor device

In a plan view of a semiconductor substrate, the semiconductor substrate includes a pillar exposing area in which the pillar region is exposed on the front surface of the semiconductor substrate, a pillar contacting area in which the pillar region is in contact with a deeper side of the anode contact region, and an anode contacting area in which the anode region is in contact with the deeper side of the anode contact region. In a direction along which the pillar contacting area and the anode contacting area are aligned, a width of the pillar contacting area is smaller than a width of the anode contacting area.

A semiconductor device for restraining snapback is provided. The semiconductor device includes IGBT and diode regions. In a view of n-type impurity concentration distribution along a direction from a front surface to a rear surface, a local minimum value of an n-type impurity concentration is located at a border between cathode and buffer regions. A local maximum value of n-type impurity concentration is located in the buffer region. At least one of the buffer and cathode regions includes a crystal defect region having crystal defects in a higher concentration than a region therearound. A peak of a crystal defect concentration in a view of crystal defect concentration distribution along the direction from the front surface to the rear surface is located in a region on the rear surface side with respect to a specific position having the n-type impurity concentration which is a half of the local maximum value.

Semiconductor device and method of manufacturing the semiconductor device

A semiconductor device includes: a semiconductor substrate, an upper electrode, a lower electrode and a gate electrode. In the semiconductor substrate, a body region, a pillar region, and a barrier region are formed. The pillar region has an n-type impurity, is formed on a lateral side of the body region, and extends along a depth from a top surface of the semiconductor substrate to a lower end of the body region. The barrier region has an n-type impurity and is formed on a lower side of the body region and the pillar region. The barrier region is formed on the lower side of the pillar region. An n-type impurity concentration distribution in a depth direction in the pillar region and the barrier region has a maximum value in the pillar region. The n-type impurity concentration distribution has a folding point on a side deeper than the maximum value.

A semiconductor device includes a semiconductor layer and a trench gate portion that extends toward a deep portion from a front surface of the semiconductor layer. The semiconductor layer includes an island region surrounded by the trench gate portion. A first side surface of the trench gate portion and a second side surface of the trench gate portion are in contact with the island region. A first conductivity type contact region that includes a first contact region that is in contact with the first side surface and a second contact region that is in contact with the second side surface is provided in the island region. Moreover, a second conductivity type contact region that is in contact with the trench gate portion at a position between the first contact region and the second contact region is provided in the island region.

A semiconductor layer of a reverse conducting insulated gate bipolar transistor is provided with a drift region of a first conductive type, a body region of a second conductive type that is disposed above the drift region, and a barrier region of the first conductive type that is disposed in the body region and electrically connects to the emitter electrode via a pillar member which extends from the one of main surfaces of the semiconductor layer. The barrier region is not contact with a side surface of the insulated trench gate.

Reverse conducting insulated gate bipolar transistor

A semiconductor layer of a reverse conducting insulated gate bipolar transistor is provided with a barrier region of the first conductive type, wherein the barrier region is disposed in the body region and electrically connects to the emitter electrode via a pillar member which extends from the one of main surfaces of the semiconductor layer. The barrier region includes a first barrier partial region, wherein a distance between the first barrier partial region and the drift region is a first distance, and a second barrier partial region, wherein a distance between the second barrier partial region and the drift region is a second distance which is longer than the first distance. The second barrier partial region is in contact with a side surface of an insulated trench gate.

A technology capable of suppressing a fluctuation in voltage in a diode region is provided. A resistance value between the emitter electrode and the lower body region is lower than a resistance value between the anode electrode and the lower anode region when the semiconductor device operates as a diode. A quantity of holes between the emitter electrode and the second barrier region is smaller than a quantity of holes between the anode electrode and the first barrier region.

A semiconductor device is provided with a silicon layer, an upper surface side aluminum layer containing silicon and an insulation film. The upper surface side aluminum layer contacts and is layered on a part of a surface of the silicon layer. The insulation film contacts and is layered on another part of the surface of the silicon layer. The insulation film is adjacent to and contacts the upper surface side aluminum layer. The insulation film includes an insulation film body and a plurality of first nodule segregated portions projecting from the insulation film body toward the upper surface side aluminum layer as seen along a vertical direction relative to the surface of the silicon layer. A corner is formed by a side surface of the insulation film body and a side surface of each of the first nodule segregated portions as seen along the vertical direction.

In an IGBT, a trench extending in a bent shape to have a corner is formed in an upper surface of a semiconductor substrate. The inside of the trench is covered with an insulating film. A gate is placed inside the trench. An emitter and a collector are formed on an upper surface and a lower surface of the semiconductor substrate, respectively. An emitter region, a body region, a drift region, and a collector region are formed in the semiconductor substrate. The emitter region is formed of an n-type semiconductor, is in contact with the insulating film, and is in ohmic contact with the emitter electrode. The body region is formed of a p-type semiconductor, is in contact with the insulating film below the emitter region, is in contact with the insulating film of an inner corner portion of the trench, and is in ohmic contact with the emitter electrode.

Insulated-gate bipolar transistor

When an IGBT has a barrier layerthat separates an upper body regionfrom a lower body region, conductivity modulation is enhanced and on-resistance decreases. When the IGBT also has a Schottky contact regionthat extends to reach the barrier layer, a diode structure can be obtained. In this case, however, a saturation current increases as well as short circuit resistance decreases. The Schottky contact regionis separated from the emitter regionby the upper body region. By selecting an impurity concentration in the region, an increase in a saturation current can be avoided. Alternatively, a block structure that prevents a depletion layer extending from the regioninto the regionfrom joining a depletion layer extending from the regioninto the regionmay be provided in an area separating the regionfrom the region

IGBT with a built-in-diode

A diode is provided with a pillar region formed so as to extend between a barrier region and an anode electrode, contact the barrier region, and made of a first conductivity type semiconductor having a concentration higher than that of the barrier region; and a barrier height adjusting region formed so as to be located between the pillar region and the anode electrode, and contact the pillar region and the anode electrode. The barrier height adjusting region includes at least one component selected from the group consisting of a second conductivity type semiconductor having a concentration lower than that of an anode region, the first conductivity type semiconductor having a concentration lower than that of the pillar region, and an i-type semiconductor. The barrier height adjusting region and the anode electrode are connected through a Schottky junction.

Growing community of inventors

Nagakute, Japan

Satoru Machida