Shin-etsu Handotai Co., Ltd.

Toru Takahashi

Hitoshi Ikeda

Yuichi Matsumoto

Tetsuro Aoyama

Kiyoshi Mitani

Tsuyoshi Ohtsuki

Susumu Higuchi

Wei Feig Qu

Yutaka Shiga

Hisao Muraki

A method for evaluating crystal defects in a silicon carbide single crystal wafer, the method including steps of: etching a silicon carbide single crystal wafer with melted KOH so that a size of an etch pit due to a threading edge dislocation is 10 to 50 μm; obtaining microscopic images by automatic photographing at a plurality of positions on a surface of the silicon carbide single crystal wafer after the etching; determining presence or absence of a defect dense part in each of all the obtained microscopic images based on a continued length of the etch pit formed by the etching; and classifying all the obtained microscopic images into microscopic images having the defect dense part and microscopic images not having the defect dense part to evaluate a dense state of crystal defects in the silicon carbide single crystal wafer.

Method for evaluating crystal defects in silicon carbide single crystal wafer

A method for manufacturing a SiC single crystal reducing crystallinity degradation at a wafer central portion wherein a growth container surrounds a heat-insulating material with a top temperature measurement hole, a seed crystal substrate at an upper portion inside the container, and a silicon carbide raw material at a lower portion of the container and sublimated to grow a SiC single crystal on the seed crystal substrate. A center position hole deviates from a center position of the seed crystal substrate and moves to the periphery side of the center of the seed crystal substrate. A SiC single crystal substrate surface is tilted by a {0001} plane and used as the seed crystal substrate. The SiC single crystal grows with the seed crystal substrate directed to a normal vector of the seed crystal substrate basal plane parallel to the main surface and identical to the hole in a cross-sectional view.

Method for manufacturing a silicon carbide single crystal by adjusting the position of a hole in a top of the growth container relative to the off angle of the silicon carbide substrate

A method for manufacturing a SiC single crystal having a growth container surrounded by a heat-insulating material, a seed crystal substrate disposed inside a top at a center of the container, a silicon carbide raw material disposed at a bottom of the container to sublimate and grow a SiC crystal to allow a center of the hole to deviate from a center position of the seed substrate to a position on a periphery side, a SiC substrate having a main surface tilted from a {0001} plane wherein a basal plane is used and grown with the seed substrate so that a direction of a component of a normal vector of the basal plane of the seed substrate parallel to the main surface and an eccentric direction of the hole are opposite directions in a cross-sectional view including the center of the seed substrate and the center of the hole.

A method for producing a semiconductor wafer having a multilayer film, in production of a semiconductor device by the steps of forming a porous layer on a surface of a semiconductor wafer by changing a surface portion into the porous layer, forming a semiconductor film on a surface of the porous layer to produce a semiconductor wafer having a multilayer film, fabricating a device on the semiconductor film, and producing the semiconductor device by delaminating the semiconductor film along the porous layer, the semiconductor film having the device formed thereon, including flattening the semiconductor wafer after delaminating and reusing the flattened semiconductor wafer, the method further including a thickness adjusting step of adjusting a whole thickness of the semiconductor wafer having a multilayer film to be produced by reusing the semiconductor wafer so as to satisfy a predetermined standard.

Semiconductor substrate having multilayer film and method to reuse the substrate by delaminating a porous layer

An epitaxial wafer comprises epitaxial layers formed on a main surface of a compound semiconductor single crystal substrate , wherein the epitaxial layer on the main surface is exposed in a back surface of the compound semiconductor single crystal substrate , and an exposed portion of the epitaxial layer has a carrier concentration of 1&times;10 cm to 2&times;10 cm . The epitaxial wafer provides for an ultra thin type light emitting diode where generation of ohmic electrode failure is suppressed.

Epitaxial wafer and light emitting diode

The invention provides a method of high productivity for the preparation of a substantially dislocation-free single crystal of a compound semiconductor such as gallium arsenide by the liquid-encapsulated Czochralski method. The improvement provided by the invention comprises admixing the melt in the crucible with an additive having an equilibrium segregation coefficient K.sub.O smaller than 1.0, which is indium in the preparation of gallium arsenide single crystals, in a concentration of at least 1.0.times.10.sup.21 atoms/cm.sup.3 of the melt and rotating the crucible at an unusually high velocity of at least 40 rpm.

Growing community of inventors

Annaka, Japan

Toru Takahashi