Mitsubishi Electric Corporation

Mitsubishi Denki Kabushiki Kaisha

Akihito Ohno

Nobuyuki Tomita

Kenichi Hamano

Yoichiro Mitani

Masayoshi Takemi

Takahiro Yamamoto

Zempei Kawazu

Takanori Tanaka

Yasuhiro Kimura

Takashi Kanazawa

Takuma Mizobe

Masashi Sakai

Atsushi Era

Kimio Shigihara

Kyosuke Kuramoto

Takuto Maruyama

A SiC substrate () has an off angle &#x3b8;&#xb0;. A SiC epitaxial layer () having a film thickness of Tm &#x3bc;m is provided on the SiC substrate (). Triangular defects () are formed on a surface of the SiC epitaxial layer (). A density of triangular defects () having a length of Tm/Tan &#x3b8;&#xd7;0.9 or more in a substrate off direction is denoted by A. A density of triangular () defects having a length smaller than Tm/Tan &#x3b8;&#xd7;0.9 in the substrate off direction is denoted by B. B/A&#x2264;0.5 is satisfied.

SiC epitaxial wafer, method for manufacturing SiC epitaxial wafer, SiC device, and power conversion apparatus

A silicon carbide substrate () is positioned such that a principal surface of the silicon carbide substrate () is parallel to a plurality of injection holes () of a horizontal CVD apparatus arranged in a row. Source gas is fed from the plurality of injection holes () to epitaxially grow a silicon carbide epitaxial growth layer () on the principal surface of the silicon carbide substrate (). The source gas fed from the plurality of injection holes () is divided into a plurality of system lines and controlled individually by separate mass flow controllers. A flow rate of the source gas on the principal surface of the silicon carbide substrate () is greater than 1 m/sec.

Manufacturing method for silicon carbide epitaxial wafer and manufacturing method for silicon carbide semiconductor device

A silicon carbide epitaxial wafer manufacturing method includes: a stabilization step of nitriding, oxidizing or oxynitriding and stabilizing silicon carbide attached to an inner wall surface of a growth furnace; after the stabilization step, a bringing step of bringing a substrate in the growth furnace; and after the bringing step, a growth step of epitaxially growing a silicon carbide epitaxial layer on the substrate by supplying a process gas into the growth furnace to manufacture a silicon carbide epitaxial wafer.

Silicon carbide epitaxial wafer manufacturing method, silicon carbide semiconductor device manufacturing method and silicon carbide epitaxial wafer manufacturing apparatus

A semiconductor wafer includes a silicon carbide substrate having a first carrier concentration, a carrier concentration transition layer, and an epitaxial layer provided on the carrier concentration transition layer, the epitaxial layer having a second carrier concentration, and the second carrier concentration being lower than the first carrier concentration. The carrier concentration transition layer has a concentration gradient in the thickness direction. The carrier concentration decreases as the film thickness increases from an interface between a layer directly below the carrier concentration transition layer and the carrier concentration transition layer, and the carrier concentration decreases at a lower rate of decrease as the film thickness of the carrier concentration transition layer increases. The carrier concentration of the carrier concentration transition layer has the concentration gradient that falls within a predetermined concentration range lying between a first concentration gradient condition and a second concentration gradient condition.

Semiconductor wafer, semiconductor device, and method for producing semiconductor device

A method for manufacturing a silicon carbide semiconductor device includes: preparing a silicon carbide single crystal substrate having a flatness with an average roughness of 0.2 nm or less; gas-etching a surface of the silicon carbide single crystal substrate under an atmosphere of a reducing gas; and forming a silicon carbide layer on the gas-etched surface of the silicon carbide single crystal substrate, wherein an etching rate of the gas etching is made in a range of 0.5 &#x3bc;m/hour or faster to 2.0 &#x3bc;m/hour or slower.

Method for manufacturing silicon carbide semiconductor device

A single-crystal 4H-SiC substrate includes a 4H-SiC bulk single-crystal substrate; and an epitaxial first single-crystal 4H-SiC layer on the 4H-SiC bulk single-crystal substrate and having recesses. The recesses have a diameter no smaller than 2 &#x3bc;m and no larger than 20 &#x3bc;m. The recesses have a depth no smaller than 0.01 &#x3bc;m and no larger than 0.1 &#x3bc;m. A single-crystal 4H-SiC substrate also includes a 4H-SiC bulk single-crystal substrate; and an epitaxial first single-crystal 4H-SiC layer on the 4H-SiC bulk single-crystal substrate and having recesses. The density of the recesses in the epitaxial first single-crystal 4H-SiC layer is at least 10/cm, and the epitaxial first single-crystal 4H-SiC layer has a defect density no larger than 2/cm.

Single-crystal 4H-SiC substrate

A substrate support for supporting a substrate when forming a film on a surface of the substrate by chemical vapor deposition. The substrate support includes a graphite material having a recessed portion for accommodating the substrate, a multilayer film on the recessed portion and consisting of a first degassing prevention film of SiC and a sublimation prevention film of TaC or HfC stacked together, and a second degassing prevention film of SiC located on portions of the graphite material other than the recessed portion.

Substrate support and semiconductor manufacturing apparatus

A method for manufacturing a single-crystal 4H&#x2014;SiC substrate includes preparing a 4H&#x2014;SiC bulk single-crystal substrate having a flat surface, and growing an epitaxial first single-crystal 4H&#x2014;SiC layer having recesses on the 4H&#x2014;SiC bulk single-crystal substrate to a thickness X, measured in micrometers (&#x3bc;m). The recesses have a diameter Y, measured in micrometers, no smaller than 0.2*X and no larger than 2*X. In addition, the recesses have a depth Z, when measured in micrometers, no smaller than (0.95*X+0.5*10), and no larger than 10*X*10.

Method for manufacturing a single-crystal 4H&#x2014;SiC substrate

A manufacturing method for manufacturing a silicon carbide epitaxial wafer includes: introducing a cleaning gas into a growth furnace to remove dendrite-like polycrystal of silicon carbide attached to an inner wall of the growth furnace; after introducing the cleaning gas, bringing a silicon carbide substrate in the growth furnace; and growing a silicon carbide epitaxial layer on the silicon carbide substrate by introducing a processing gas into the growth furnace to manufacture a silicon carbide epitaxial wafer, wherein the cleaning gas having fluid energy of 1.6E-4 [J] or higher is introduced into the growth furnace.

Manufacturing method and apparatus for manufacturing silicon carbide epitaxial wafer

A method of manufacturing a semiconductor element includes a first step of epitaxially growing an AlN layer on a substrate, a second step of forming a buffer layer on the AlN layer by epitaxially growing AlGaInN where x, y, and z satisfy x+y+z=1 and y is not zero without adding Fe, a third step of forming a resistance layer on the buffer layer by epitaxially growing AlGaInN where x, y, and z satisfy x+y+z=1 and y is not zero while adding Fe, a step of epitaxially growing a channel layer on the resistance layer, a step of epitaxially growing an electron supply layer above the channel layer, and a step of forming an electrode above the electron supply layer.

Method of manufacturing semiconductor element

A method for manufacturing a single-crystal 4H-SiC substrate includes: preparing a flat 4H-SiC bulk single-crystal substrate; and epitaxially growing a first single-crystal 4H-SiC layer having recesses on the 4H-SiC bulk single-crystal substrate, wherein the first single-crystal 4H-SiC layer has a thickness of X (&#x3bc;m), the recesses have a diameter Y (&#x3bc;m) no smaller than 0.2*X (&#x3bc;m) and no larger than 2*X (&#x3bc;m), and a depth of Z (nm) no smaller than (0.95*X (&#x3bc;m)+0.5 (nm)) and no larger than 10*X (&#x3bc;m).

A manufacturing method of a high electron mobility transistor includes: forming a GaN channel layer on a semi-insulating substrate in a first growth condition; forming a transition layer on the GaN channel layer while the first growth condition is changed to a second growth condition; and forming an AlGaN electron supply layer on the transition layer in the second growth condition, wherein the GaN channel layer, the transition layer, and the AlGaN electron supply layer are continuously formed without interrupting growth.

Manufacturing method of high electron mobility transistor

A semiconductor laser includes: a DBR (Distributed Bragg Reflector) region having a diffraction grating; a FP (Fabry-Perot) region having no diffraction grating; and an optical waveguide section placed between the DBR region and an outputting end surface. A length of the optical waveguide section is longer than a length of the DBR region in a resonator length direction.

Semiconductor laser

A nitride semiconductor light-emitting device includes a p-type contact layer, a p-type intermediate layer below the p-type contact layer, and a p-type cladding layer below the p-type intermediate layer. Band gap energy differences between the p-type contact layer and the p-type intermediate layer and also between the p-type intermediate layer and the p-type cladding layer are, respectively, 200 meV or below.

Growing community of inventors

Tokyo, Japan

Akihito Ohno