Nippon Pillar Packing Co., Ltd.

Shimadzu Corporation

Nissin Electric Co., Ltd.

Nippon Packing Co., Ltd.

Kichiya Tanino

Masanobu Hiramoto

Yasuhiro Akune

Masaru Koeda

Tetsuya Nagano

Kazuo Sano

Yoshimitsu Yamada

Nobuhiro Munetomo

Eiji Ishiguro

Toshihisa Maeda

In a single crystal SiC composite material for producing a semiconductor device, and a method of producing the same according to the invention, a single crystal SiC film which is produced on an Si substrate by the heteroepitaxial growth method and obtained by removing the Si substrate, is stacked and bonded via a film-like SiO layer onto the surface of a polycrystalline plate consisting of Si and C atoms in a closely contacted manner forming thereby a stacked composite member. The stacked composite member is then heat-treated, whereby single crystal SiC in which the crystal is transformed in the same orientation as the single crystal of the single crystal SiC film is integrally grown on the polycrystalline plate. The thickness and the strength which are requested for producing a semiconductor device can be ensured, and lattice defects and micropipe defects seldom occur, so that an accurate and high-quality semiconductor device can be produced.

Single crystal SiC composite material for producing a semiconductor device, and a method of producing the same

According to the invention, a complex (M or M&prime;) formed by stacking in a closely contacted state a single crystal &agr;-SiC base material ( ) and a polycrystalline plate ( ) which is produced into a plate-like shape by the CVD method with interposing an intermediate layer ( or &prime;) containing Si and O as fundamental components, such as silicon rubber between opposing faces of the two members ( ) and ( ) in a laminated manner is heat-treated at a temperature of 2,200&deg; C. or higher, and under a saturated SiC vapor pressure, thereby causing polycrystal members of the polycrystalline plate ( ) to be transformed in a same direction as single crystal of the single crystal &agr;-SiC base material ( ) to integrally grow single crystal. Therefore, single crystal SiC of a high quality in which crystal defects and distortion are prevented from occurring and micropipe defects hardly occur can be produced easily and efficiently.

Material for raising single crystal SiC and method of preparing single crystal SiC

In single crystal SiC , growing single crystal SiC is integrally formed on a surface of a single crystal hexagonal (6H type) &agr;-SiC substrate used as a seed crystal. The number of micropipes A of the growing single crystal SiC is less than that of the micropipes B of the single crystal &agr;-SiC substrate , and the thickness t thereof is less than the thickness t of the single crystal &agr;-SiC substrate , thereby making it possible to obtain the high quality-single crystal SiC wherein the number of the micropipes per unit area is less, thereby decreasing the distortion in the neighborhood of the micropipes. This can provide the high-quality single crystal SiC which can be practically used as a substrate wafer for fabricating a semiconductor device.

Single crystal SiC

An object constructed of silicon carbide is made up of a plurality of sintered silicon carbide component parts in simple solid forms. This approach allows the production of objects having configurations that are obtainable only with difficulty or not at all by prior art approaches. The component parts are inseparably connected together by means of a silicon carbide film integrally formed on said component parts by chemical vapor deposition. In order to provide substantially improved joint strength and overall structural strength, the silicon carbide film preferably has a crystal structure in which the X-ray diffraction intensity ratio of each crystal face to the (111) face is 0.1 to 10 and/or in which the aspect ratio of crystal grains is 1 to 30.

Objects constructed of silicon carbide

According to the present invention, a complex (M) which is formed by growing a polycrystalline &bgr;-SiC plate 2 having a thickness of 10 &mgr;m or more on the surface of a single crystal &agr;-SiC base material 1 by the PVD method or the thermal CVD method is heat-treated at a temperature of the range of 1,650 to 2,400&deg; C., whereby polycrystals of the polycrystalline cubic &bgr;-SiC plate 2 are transformed into a single crystal, and the single crystal oriented in the same direction as the crystal axis of the single crystal &agr;-SiC base material 1 is grown. As a result, single crystal SiC of high quality which is substantially free from micropipe defects and defects affected by the micropipe defects can be produced easily and efficiently.

Single crystal SIC and method of producing the same

The single crystal SiC according to the present invention is produced in the following manner. Two complexes M in each of which a polycrystalline film,of &bgr;-SiC (or &agr;-SiC) is grown on the surface of a single crystal &agr;-SiC substrate,by thermochemical deposition, and the surface,of the polycrystalline film,is ground so that the smoothness has a surface roughness of 200 angstroms RMS or smaller, preferably 100 to 50 angstroms RMS are subjected to a heat treatment under a state where the complexes are closely fixed to each other via their ground surfaces,at a temperature of 2,000&deg; C. or higher and in an atmosphere of a saturated SiC vapor pressure, whereby the polycrystalline films,of the complexes M are recrystallized to grow a single crystal which is integrated with the single crystal &agr;-SiC substrates,Large-size single crystal SiC in which impurities, micropipe defects, and the like do not remain, and which has high quality can be produced with high productivity.

Single crystal SiC and a method of producing the same

In single crystal SiC according to the present invention, a single crystal &agr;-SiC substrate and a polycrystalline &bgr;-SiC plate are laminated to each other for fixation, the single crystal &agr;-Sic substrate and the polycrystalline &bgr;-SiC plate are subjected to heat treatment under an inert gas atmosphere and a saturated SiC vapor atmosphere, whereby the single crystallization owing to solid-phase transformation of the polycrystalline &bgr;-SiC plate and a progress of the single crystallization to a surface direction wherein a contact point is regarded as a starting point make a whole surface of layer of the polycrystalline &bgr;-SiC plate grow efficiently into a single crystal integrated with the single crystal &agr;-SiC substrate, whereby it is possible to produce single crystal SiC having high quality with high productivity, which is substantially free from lattice defects and micropipe defects.

Single crystal SIC and a method of producing the same

Single crystal and method of producing the same

A specular-surface body (1) which has a sufficient resistance against irradiation of high energy beams--such as X-rays, SOR beams, laser beams, etc.--can be suitably used as reflecting mirrors, diffraction gratings, etc. for such high energy beams. The specular-surface body is formed by a silicon carbide film (3) being formed by chemical vapor deposition on a surface of a substrate (2) of silicon carbide sintered material, the film surface then being processed to be a specular surface (3a). There is a defect-free crystal layer (3b) at a depth d of 300 .ANG. from the specular surface (3a) of the silicon carbide film 3. The silicon carbide film (3) has a crystal structure strongly oriented to one crystal plane (for example, the (220) plane) specified by Miller indices in such a manner that its X-ray diffraction intensity ratio becomes 90% or more at a peak intensity.

Specular-surface body

The surface 1a of a single crystal .alpha.-SiC substrate 1 is adjusted so as to have a surface roughness equal to or lower than 2,000 angstroms RMS, and preferably equal to or lower than 1,000 angstroms RMS. On the surface 1a of the single crystal .alpha.-SiC substrate 1, a polycrystalline .alpha.-SiC film 2 is grown by thermal CVD to form a complex is placed in a porous carbon container and the carbon container is covered with .alpha.-SiC powder. The complex is subjected to a heat treatment at a temperature equal to or higher than a film growing temperature, i.e., in the range of 1,900 to 2,400.degree. C. in an argon gas flow, whereby single crystal .alpha.-SiC is integrally grown on the single crystal .alpha.-SiC substrate 1 by crystal growth and recrystallization of the polycrystalline .alpha.-SiC film 2. It is possible to stably and efficiently produce single crystal SiC of a large size which has a high quality and in which any crystal nucleus is not generated.

The present invention discloses diffraction gratings which do not generate any thermal strain and can perform extremely high-precision and high-efficiency diffraction nearly free from scattered beams. The diffraction gratings are built by allowing the chemically deposited film of silicon carbide whose crystal planes are strongly oriented to the (220) planes in terms of Miller indices to form on the substrate comprising sintered silicon carbide, polishing the surface of the deposited film to 5 .ANG. RMS or less, and directly etched laminar-type grating grooves on that surface by using ion-beam etching.

Diffraction grating

A composite material for use as a construction material for high energy density beam reflectors and for other purposes, comprising a substrate and a chemically vapor deposited layer of silicon carbide formed thereon, wherein the crystal faces in said chemically vapor deposited layer of silicon carbide are oriented to the (220) plane as indicated by Miller indices.

Growing community of inventors

Sanda, Japan

Kichiya Tanino