Mitsubishi Electric Corporation

Renesas Electronics Corporation

Yasuhiro Kagawa

Rina Tanaka

Yutaka Fukui

Masayuki Imaizumi

Naruhisa Miura

Katsutoshi Sugawara

Akihiko Furukawa

Shiro Hino

Yuji Abe

Hiroshi Watanabe

Kensuke Taguchi

Atsushi Narazaki

Shuhei Nakata

Tsuyoshi Kawakami

Nobuo Fujiwara

Yuji Ebiike

Tomohide Terashima

Takeharu Kuroiwa

Satoshi Yamakawa

Yoshiyuki Nakaki

Kenichi Ohtsuka

Kohei Ebihara

Kazuyasu Nishikawa

Kenji Hamada

Shoyu Watanabe

Kazuya Ishibashi

An object of the present disclosure is to suppress decrease in withstand voltage and increase in ON voltage and to increase body diode current. An SiC-MOSFET includes: a source region formed on a surface layer of a base region; a gate electrode facing a channel region which is a region of the base region sandwiched between a drift layer and the source region via a gate insulating film; a source electrode having electrically contact with the source region; and a plurality of first embedded regions of a second conductivity type formed adjacent to a lower surface of the base region. The plurality of first embedded regions are formed immediately below at least both end portions of the base region, and three or more first embedded regions are formed to be separated from each other.

SiC-mosfet

A drift layer has a first conductivity type and is provided on a silicon carbide substrate. A well region has a second conductivity type and is provided on the drift layer. A source region has the first conductivity type and is provided on the well region. A gate trench has an inner surface with a bottom located at a deeper position than the well region and a lateral part continuous with the bottom. An electric field relaxation region has the second conductivity type and has at least a part located below the bottom of the gate trench. A surge relaxation region has the first conductivity type, contacts at least a part of the bottom of the gate trench, and is separated from the drift layer by the electric field relaxation region.

Silicon carbide semiconductor device, power converter, and method of manufacturing silicon carbide semiconductor device

A semiconductor device includes a trench-type switching element formed in an active region and a trench-type current sense element formed in a current sense region. Below a trench in which a gate electrode of the switching element is embedded, a trench in which a gate electrode of the current sense element is embedded, and a trench formed at the boundary portion between the active region and the current sense region, protective layers are formed, respectively. The protective layer at the boundary portion between the active region and the current sense region has a divided portion that is divided in a direction from the active region to the current sense region.

Semiconductor device

There is provided a technique for suppressing the operation of a parasitic transistor in a semiconductor device having a voltage sense structure. The semiconductor device includes: a semiconductor layer; a first impurity region; a second impurity region; a first semiconductor region; a second semiconductor region; a first electrode; a second electrode; and a third electrode. The second impurity region includes a low lifetime region at least under the second semiconductor region. The low lifetime region is a region having a defect density higher than that in a surface layer of the second impurity region or a region in which a heavy metal is diffused.

Semiconductor device and method of manufacturing same

A drift layer contains first conductivity type impurities. A well region contains second conductivity type impurities. A source region is provided on the well region and contains the first conductivity type impurities. A well contact region is in contact with the well region, contains the second conductivity type impurities, and has an impurity concentration on the second surface higher than the impurity concentration on the second surface in the well region. A gate electrode is provided on a gate insulating film. A Schottky electrode is in contact with the drift layer. A source ohmic electrode is in contact with the source region. A resistor is in contact with the well contact region and has higher resistance per unit area than the source ohmic electrode.

Silicon carbide semiconductor device and power conversion apparatus

A first semiconductor layer of a first conductivity type, a first semiconductor region of a second conductivity type provided in an upper layer part thereof, a second semiconductor region of the first conductivity type provided in the upper layer part thereof, a gate trench penetrating through the first and second semiconductor regions in a thickness direction and a bottom surface thereof reaching inside of the first semiconductor layer, a gate insulating film in the gate trench, a gate electrode embedded in the gate trench, a second semiconductor layer of the second conductivity type provided so as to extend, from the bottom surface of the gate trench, a third semiconductor layer of the second conductivity type extending to a position deeper than the bottom surface of the gate trench, and a fourth semiconductor layer of the first conductivity type interposed between the second semiconductor layer and the third semiconductor layer in the position deeper than the bottom surface of the gate trench.

Semiconductor device and method of manufacturing thereof, and power conversion apparatus

An insulated gate silicon carbide semiconductor device includes: a drift layer of a first conductivity type on a silicon carbide substrate of 4H type with a {0001} plane having an off-angle of more than 0&#xb0; as a main surface; a first base region; a source region; a trench; a gate insulating film; a protective diffusion layer; and a second base region. The trench sidewall surface in contact with the second base region is a surface having a trench off-angle of more than 0&#xb0; in a &#x3c;0001&#x3e; direction with respect to a plane parallel to the &#x3c;0001&#x3e; direction. The insulated gate silicon carbide semiconductor device can relieve an electric field of a gate insulating film and suppress an increase in on-resistance and provide a method for manufacturing the same.

Insulated gate silicon carbide semiconductor device and method for manufacturing same

A trench-gate semiconductor device including an outside trench, increases reliability of an insulating film at a corner of an open end of the outside trench. The semiconductor device includes: a gate trench reaching an inner part of an n-type drift layer in a cell region; an outside trench outside the cell region; a gate electrode formed inside the gate trench through a gate insulating film; a gate line formed inside the outside trench through an insulating film; and a gate line leading portion formed through the insulating film to cover a corner of an open end of the outside trench closer to the cell region, and electrically connecting the gate electrode to the gate line, and the surface layer of the drift layer in contact with the corner has a second impurity region of p-type that is a part of the well region.

Semiconductor device having a gate trench and an outside trench

A gate trench and a protective trench are provided on a top surface of the silicon carbide semiconductor layer of a first conductivity type. A protective diffusion layer of a second conductivity type is provided at a position deeper than the gate electrode in the silicon carbide semiconductor layer. An inter-layer insulating film covers a surface of the gate electrode and includes a cell opening. A source electrode is electrically connected to the source region via the cell opening and electrically connected to the protective diffusion layer via the protective trench. A plated film is provided on the source electrode. A concave part is provided on a top surface of the source electrode above the protective trench. A depth in a vertical direction of the concave part is equal to or less than half of a width in a horizontal direction of the concave part.

Silicon carbide semiconductor device, manufacturing method therefor and power conversion apparatus

A gate insulating film covers a trench penetrating through a source region and a body region and reaching a drift layer in each of a first cell region and a second cell region. The gate electrode is provided in the trench. A high-concentration layer of the first conductivity type is provided between the drift layer and the body region in the first cell region and has a second impurity concentration higher than the first impurity concentration. A current restriction layer is provided between the drift layer and the body region in the second cell region and has the first conductivity type and a third impurity concentration higher than the first impurity concentration and lower than the second impurity concentration.

Silicon carbide semiconductor device

A semiconductor device includes a base region of second conductivity type formed on a drift layer of first conductivity type, a source region of first conductivity type located in the base region, a trench passing through the base region and the source region and dividing cell regions in plan view, a protective diffusion layer of second conductivity type disposed on a bottom of the trench, a gate electrode embedded in the trench with a gate insulating film therebetween, a source electrode electrically connected to the source region, and a protective contact region disposed at each of positions of three or more cell regions and connecting the protective diffusion layer and the source electrode to each other. The protective contact regions are disposed such that a triangle whose vertices are centers of three protective contact regions located closest to one another is an acute triangle.

A protective diffusion region includes a first protective diffusion region at a location closest to a termination region, and a second protective diffusion region located away from the first protective diffusion region with a first space therebetween. A second space that is a distance between a termination diffusion region and the first protective diffusion region is greater than the first space. A current diffusion layer of a first conductivity type includes a first current diffusion layer located between the first protective diffusion region and the second protective diffusion region and having a higher impurity concentration than a drift layer, and a second current diffusion layer located between the first protective diffusion region and the termination diffusion region. The second current diffusion layer includes a region having a lower impurity concentration than the current diffusion layer.

Power semiconductor device

A silicon carbide semiconductor device includes a silicon carbide drift layer formed on an upper surface of a silicon carbide semiconductor substrate having an off angle, a body region, a source region, a plurality of trenches, a gate insulating film, a gate electrode, a source electrode, a drain electrode, and a depletion suppressing layer. The depletion suppressing layer is positioned to be sandwiched between the plurality of trenches in a plan view, and in a direction with the off angle of the silicon carbide semiconductor substrate, a distance between the depletion suppressing layer and one of the trenches adjacent to the depletion suppressing layer is different from another distance between the depletion suppressing layer and the other one of the trenches adjacent to the depletion suppressing layer.

A drift layer of a first conductivity type is made of silicon carbide. A body region of a second conductivity type is provided on the drift layer. A source region of the first conductivity type is provided on the body region. A source electrode is connected to the source region. A gate insulating film is provided on side and bottom surfaces of a trench which penetrates the body region and the source region. A gate electrode is provided in the trench with the gate insulating film interposed therebetween. A trench-bottom-surface protective layer of the second conductivity type provided below the bottom surface of the trench in the drift layer is electrically connected to the source electrode. The trench-bottom-surface protective layer has a high-concentration protective layer, and a first low-concentration protective layer provided below the high-concentration protective layer and having an impurity concentration lower than that of the high-concentration protective layer.

Silicon carbide semiconductor device and method for manufacturing same

There is provided a trench-gate type semiconductor device that can prevent breakdown of a gate insulating film caused by a displacement current flowing into a protective diffusion layer at a portion of a trench underlying a gate electrode at a turn-off time and simultaneously improves a current density by narrowing a cell pitch. The semiconductor device has a gate electrodeembedded into a trenchpenetrating a base region. The gate electrodeis disposed into a lattice shape in a planar view, and a protective diffusion layeris formed in a drift layerat the portion underlying thereof. At least one of blocks divided by the gate electrodeis a protective contact regionon which the trenchis entirely formed. A protective contactfor connecting the protective diffusion layerat a bottom portion of the trenchand a source electrodeis disposed on the protective contact region

Growing community of inventors

Tokyo, Japan

Yasuhiro Kagawa