Mitsubishi Denki Kabushiki Kaisha

Mitsubishi Electric Corporation

Hiroaki Sumitani

Hiroshi Watanabe

Kenichi Ohtsuka

Kenichi Hamano

Sunao Aya

Hideki Yabe

Koji Kise

Kenji Marumoto

Takashi Hifumi

Yuji Abe

Takeharu Kuroiwa

Masayuki Imaizumi

Masayoshi Tarutani

Naoki Yutani

Nobuyuki Tomita

Toshimasa Tomoda

Kenichi Kuroda

Yoichiro Mitani

Takao Sawada

Tomoaki Furusho

Yoshihiko Ozaki

Kenji Kusano

Fumihide Sato

A substrate mounting member according to the present invention is a member for mounting a SiC substrate for epitaxial growth, which includes a wafer plate including a SiC polycrystal, and a supporting plate configured to be placed on the wafer plate, include no SiC polycrystal and have a surface serving as a SiC substrate placing surface, the surface being on the side opposite to a surface in contact with the wafer plate, and in which a thickness h [mm] of the supporting plate satisfies an expression h&#x2264;3 pa(1&#x2212;v){(5+v)/(1+v)}/16E when a force applied to a unit area of the supporting plate by a self-weight of the supporting plate and by the SiC substrate is represented as p [N/mm], a radius of the supporting plate as a [mm], a Poisson's ratio as v and a Young's modulus as E [MPa].

Substrate mounting member, wafer plate, and SiC epitaxial substrate manufacturing method

A silicon carbide semiconductor element, including: i) an n-type silicon carbide substrate doped with a dopant, such as nitrogen, at a concentration C, wherein the substrate has a lattice constant that decreases with doping; ii) an n-type silicon carbide epitaxially-grown layer doped with the dopant, but at a smaller concentration than the substrate; and iii) an n-type buffer layer doped with the dopant, and arranged between the substrate and the epitaxially-grown layer, wherein the buffer layer has a multilayer structure in which two or more layers having the same thickness are laminated, and is configured such that, based on a number of layers (N) in the multilayer structure, a doping concentration of a K-th layer from a silicon carbide epitaxially-grown layer side is C&#xb7;K/(N+1).

Epitaxial wafer and semiconductor element

A method is provided in order to manufacture a silicon carbide epitaxial wafer whose surface flatness is very good and has a very low density of carrot defects and triangular defects arising after epitaxial growth. The silicon carbide epitaxial wafer is manufactured by a first step of annealing a silicon carbide bulk substrate that is tilted less than 5 degrees from &#x3c;0001&#x3e; face, in a reducing gas atmosphere at a first temperature Tfor a treatment time t, a second step of reducing the temperature of the substrate in the reducing gas atmosphere, and a third step of performing epitaxial growth at a second temperature Tbelow the annealing temperature Tin the first step, while supplying at least a gas including silicon atoms and a gas including carbon atoms.

Method of manufacturing silicon carbide epitaxial wafer

The X-ray mask manufactured according to the present invention can solve a problem that the thin film stress of the X-ray absorber cannot be made to be zero although the mean thin film stress throughout the X-ray absorber can be made to be zero. The thin film stress distribution over the X-ray absorber 4 after the X-ray absorber 4 has been formed on a silicon substrate 1 is measured, and then inputs of electric power to heaters 9a, 9b and 9c of a hot plate 8 are changed so as to heat the X-ray absorber 4 to temperatures according to a specified temperature distribution with which the thin film stress throughout the X-ray absorber can be made to be zero.

Method of manufacturing X-ray mask and heating apparatus

A method of imaging an object by the ultrasonic or electromagnetic wave by mechanically or electronically scanning the ultrasonic or electromagnetic wave transmitting/receiving system to transmit the ultrasonic or electromagnetic wave beam spreading in space of the object and using the trace (TOF locus) from the transmission to the reception while receiving the reflected wave from the object, and sequentially reproducing the line image at the central line of the synthetic aperture range using the received signal group from the scanning points in the synthetic aperture range to sequentially image the area to be imaged while scanning the ultrasonic or electromagnetic wave transmitting/receiving system. An imaging apparatus applied with the method has a relatively simple hardware structure for reproducing the image and is also able to perform the operation in real time.

Method of imaging an object by ultrasonic or electromagnetic waves

Growing community of inventors

Tokyo, Japan

Hiroaki Sumitani