Hitachi, Ltd.

Renesas Technology Corp.

Naoki Tega

Digh Hisamoto

Naoki Watanabe

Takeru Suto

Yasuhiro Shimamoto

Yuki Mori

Hiroshi Miki

Ryuta Tsuchiya

Keisuke Kobayashi

Takashi Takahama

Hirotaka Hamamura

Mieko Matsumura

Shintaroh Sato

Hiroyuki Matsushima

Satoru Akiyama

Tetsuya Ishimaru

Junichi Sakano

Daisuke Matsumoto

Hiroyuki Yoshimoto

Koji Fujisaki

Haruka Shimizu

Toshiyuki Ohno

Kumiko Konishi

Yuan Bu

Hiroyuki Okino

Tadao Morimoto

In a SiC power MISFET having a lateral surface of a trench formed in an upper surface of a SiC epitaxial substrate as a channel region, a silicon carbide semiconductor device having low resistance, high performance, and high reliability is realized. As a means therefor, a SiC power MISFET is formed as an island-shaped unit cell on an upper surface of an n-type SiC epitaxial substrate that is provided with a drain region on a bottom surface thereof, the SiC power MISFET including: an n-type current diffusion region that surrounds a p-type body layer contact region and an n-type source region in the indicated order in a plan view; a p-type body layer and an n-type JFET region; a trench that is formed on the body layer so as to span between the source region and the current diffusion region adjacent each other in a first direction and extends in the first direction; and a gate electrode embedded in the trench with a gate insulating film therebetween.

Silicon carbide semiconductor device, power conversion device, three-phase motor system, automobile, and railway vehicle

Abnormal generation of heat of a power MOSFET is detected to improve the reliability of a semiconductor device. As its means, in a power MOSFET having a drain electrode on the side of a back surface of a semiconductor substrate and a source pad on the side of a main surface of the semiconductor substrate, two gate pads electrically connected to a gate pad connected to a gate electrode of the power MOSFET are formed on the side of the main surface of the semiconductor substrate. Further, there is provided a voltmeter connected in parallel with each of two current paths which connect the two gate pads and a gate driver.

Semiconductor device

Provided is a semiconductor device whose performance is improved. A p type body region is formed in an n type semiconductor layer containing silicon carbide, and a gate electrode is formed on the body region with a gate insulating film interposed therebetween. An n type source region is formed in the body region on a side surface side of the gate electrode, and the body region and a source region are electrically connected to a source electrode. A p type field relaxation layer FRL is formed in the semiconductor layer on the side surface side of the gate electrode, and the source electrode is electrically connected to the field relaxation layer FRL. The field relaxation layer FRL constitutes a part of the JFET 2Q which is a rectifying element, and a depth of the field relaxation layer FRL is shallower than a depth of the body region.

A plurality of trench gate electrodes are formed from an upper surface to reach an intermediate depth of an n-type SiC epitaxial substrate including an n-type drain region on a lower surface and an n-type source region on an upper surface in contact with the source region to be arranged in a direction along the upper surface. Here, at least three side surfaces among four side surfaces of each of the trench gate electrodes having a rectangular planar shape are in contact with a p-type body layer below the source region. In addition, a JFET region in the SiC epitaxial substrate and a source electrode connected to the source region immediately above the JFET region extend along a direction in which the plurality of trench gate electrodes are arranged.

Silicon carbide semiconductor device

A silicon carbide semiconductor device includes an n-type silicon carbide semiconductor substrate, a drain electrode electrically connected to a rear face, an n-type semiconductor layer having a second impurity concentration lower than the first impurity concentration, a p-type first semiconductor region, an n-type second semiconductor region, and an n-type third semiconductor region. A trench is formed having a gate electrode therein in which the bottom face of the trench contacts the p-type semiconductor region. A metal layer is electrically connected to the third semiconductor region, and a source electrode electrically connects the second semiconductor region and the metal layer to each other.

Silicon carbide semiconductor device with horizontal and vertical current flow

An object of the present invention is to provide high-performance highly-reliable power semiconductor device. The semiconductor device according to the present invention is provided with a first conductive type semiconductor substrate, a drain electrode formed on a back side of the semiconductor substrate, a drift layer of the first conductive type formed on a surface side of the semiconductor substrate, a source area of the first conductive type, a current diffused layer of the first conductive type, a body layer of a second conductive type reverse to the first conductive type in contact with the source area and the current diffused layer, a trench which pierces the source area, the body layer and the current diffused layer, which is shallower than the body layer, and the bottom of which is in contact with the body layer, a high-concentration JFET layer of the first conductive type formed up to a deeper position than a boundary between the current diffused layer and the body layer, electrically connecting the drift layer and the current diffused layer, and having higher impurity concentration than the drift layer, a gate insulating film formed on an inner wall of the trench, and a gate electrode formed on the gate insulating film.

Semiconductor device and method for manufacturing same, power conversion device, three-phase motor system, automobile, and railway carriage

To solve a problem of realizing a large current and highly reliable power semiconductor device while shrinking a unit cell. A semiconductor device according to the present invention includes a plurality of p-type body regions extending in a first direction. The semiconductor device further includes: a JFET region formed to extend in the first direction between p-type body regions which are adjacent to each other in a second direction orthogonal to the first direction; an n-type source region formed to extend in the first direction within a p-type body region and separate from an end side surface of the p-type body; and a channel region formed to extend in the first direction and in a top layer portion of a p-type body region between an end side surface of the p-type body region and an end side surface of an n-type source region.

Semiconductor device and power conversion device

A MOSFET using a SiC substrate has a problem that a carbon-excess layer is formed on a surface by the application of mechanical stress due to thermal oxidation and the carbon-excess layer degrades mobility of channel carriers. In the invention, (1) a layer containing carbon-carbon bonds is removed; (2) a gate insulating film is formed by a deposition method; and (3) an interface between a crystal surface and the insulating film is subjected to an interface treatment at a low temperature for a short time. Due to this, the carbon-excess layer causing characteristic degradation is effectively eliminated, and at the same time, dangling bonds can be effectively eliminated by subjecting an oxide film and an oxynitride film to an interface treatment.

Silicon carbide semiconductor device and method for manufacturing same

An object of the present invention is to provide high-performance highly-reliable power semiconductor device. The semiconductor device according to the present invention is provided with a semiconductor substrate of a first conductive type, a drain electrode formed on a back side of the semiconductor substrate, a drift layer of the first conductive type formed on a semiconductor substrate, a source area of the first conductive type, a current-diffused layer of the first conductive type electrically connected to the drift layer, a body layer of a second conductive type reverse to the first conductive type in contact with the source area and the current-diffused layer, a trench which pierces the source area, the body layer and the current-diffused layer, which is shallower than the body layer, and the bottom of which is in contact with the body layer, a gate insulating film formed on an inner wall of the trench, a gate electrode formed on the gate insulating film, and a gate insulating film protective layer formed between the current-diffused layer and the gate electrode.

Semiconductor device, method for manufacturing same, power conversion device, three-phase motor system, automobile, and railway carriage

Disclosed herein is a technique for realizing a high-performance and high-reliability silicon carbide semiconductor device. A trenched MISFET with a trench formed into the drift through a p-type body layerincludes an n-type resistance relaxation layercovering the bottom portion of the trench, and a p-type field relaxation layer. The p-type field relaxation layeris separated from the trench bottom portion via the resistance relaxation layer, and is wider than the resistance relaxation layer. This achieves a low ON resistance, high reliability, and high voltage resistance at the same time. By forming the field relaxation layer beneath the trench, feedback capacitance can be controlled to achieve a high switching rate and high reliability.

Silicon carbide semiconductor device and method for producing same

In order to provide a high-performance and reliable silicon carbide semiconductor device, in a silicon carbide semiconductor device including an n-type SiC epitaxial substrate, a p-type body layer, a p-type body layer potential fixing region and a nitrogen-introduced n-type first source region formed in the p-type body layer, an n-type second source region to which phosphorus which has a solid-solubility limit higher than that of nitrogen and is easily diffused is introduced is formed inside the nitrogen-introduced n-type first source region so as to be separated from both of the p-type body layer and the p-type body layer potential fixing region.

Silicon carbide semiconductor device and manufacturing method of the same

A technique for improving characteristics of a semiconductor device (DMOSFET) is provided. A semiconductor device is configured so as to include: an n-type source layer () disposed on an upper portion of a first surface side of an SiC substrate (); a p body layer () which surrounds the source layer and has a channel region; an n-type drift layer () which is in contact with the p body layer (); a gate electrode () which is disposed on an upper portion of the channel region via a gate insulating film; and a first player () which is disposed in the p body layer (), extends to a portion below the nsource layer (), and serves as a buried semiconductor region having an impurity concentration higher than that of the p body layer (). In this manner, since the first player () is formed in the middle of the p body layer (), it is possible to reduce the diffusion resistance of the p body layer (). Thus, it is possible to make a parasitic bipolar transistor harder to turn on.

Semiconductor device and manufacturing method of semiconductor device

When a gate length is reduced for the purpose of reducing on-resistance in a SiC DOMSFET, it is difficult to achieve both of the reduction of on-resistance by the reduction of gate length and the high element withstand voltage at the same time. In the present invention, a body layer is formed after the source diffusion layer region is formed and then a portion of the source diffusion layer region is recessed. Because of the presence of the body layer, the distances between the source diffusion region and respective end portions can be increased, a depletion layer is effectively expanded, and electric field concentration at the end portions can be suppressed, thereby improving withstand voltage characteristics. Consequently, the present invention can provide a silicon carbide semiconductor device that achieves both of the reduction of channel resistance by the reduction of gate length and the high element withstand voltage at the same time.

Silicon carbide semiconductor device and manufacturing method thereof

A SiC MOSFET has a subject that resistance in the source region is increased when annealing for metal silicidation is performed to a source region before forming the gate insulating film, the metal silicide layer of the source region is oxidized by an oxidizing treatment (including oxynitriding treatment) when the gate insulating film is formed. When a metal silicide layer to be formed on the surface of a SiC epitaxial substrate is formed before forming a gate insulating film interface layer (oxide film), and an anti-oxidation film for the metal silicide is formed on the metal silicide layer, it is possible to suppress oxidation of the metal silicide layer by the oxidizing treatment upon forming the gate insulating film interface layer and the resistance of the source region can be decreased without lowering the channel mobility.

In a MOSFET using a SiC substrate, a source region having low resistance and high injection efficiency is formed without performing a high-temperature heat treatment. A vertical Schottky barrier transistor in which a source region SR on a SiC epitaxial substrate is constituted by a metal material is formed. The source region SR composed of a metal material can be brought into a low resistance state without performing a high-temperature activation treatment. Further, by segregating a conductive impurity DP at an interface between the source region SR composed of a metal material and the SiC epitaxial substrate, the Schottky barrier height can be reduced, and the carrier injection efficiency from the source region SR can be improved.

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Tokyo, Japan

Naoki Tega