Patent classifications
C30B35/007
METHOD OF GROWING SEMI-INSULATING SILICON CARBIDE SINGLE CRYSTAL INGOT AND APPARATUS FOR GROWING SILICON CARBIDE SINGLE CRYSTAL INGOT
A method of growing a semi-insulating SiC single crystal ingot, the method comprising the steps of: (1) placing a dopant coated with silicon carbide (SiC) and a carbon-based material into a reaction vessel containing a seed crystal fixed thereto; and (2) growing a SiC single crystal on the seed crystal, thereby yielding a high-quality semi-insulating SiC single crystal ingot with a uniform thickness-based doping concentration. In addition, another embodiment relates to a method of growing a semi-insulating silicon carbide single crystal ingot, the method comprising the steps of: (a) placing in a reaction vessel, a composition comprising a carbon-containing polymer resin, a solvent, a dopant, and silicon carbide (SiC); (b) solidifying the composition; and (c) growing a SiC single crystal ingot on a seed crystal fixed to the reaction vessel, thereby yielding a high-quality semi-insulating SiC single crystal ingot with a uniform thickness-based doping concentration.
POLYCRYSTALLINE SILICON ROD, PROCESSING METHOD FOR POLYCRYSTALLINE SILICON ROD, METHOD FOR EVALUATING POLYCRYSTALLINE SILICON ROD, AND METHOD FOR PRODUCING FZ SINGLE CRYSTAL SILICON
For evaluating a polycrystalline silicon rod to be used as a raw material for production of FZ Si single crystals, novel evaluation values (values of characteristics×amount of crystals) including the amount of crystals grown in the growth direction (radial direction) are defined and the homogeneity in crystal characteristics in the growth direction (radial direction) is evaluated. Specifically, the homogeneity of the polycrystalline rod is evaluated by sampling a plurality of specimen plates each having, as a principal plane thereof, a cross-section perpendicular to a radial direction of the polycrystalline rod grown by a Siemens method at equal intervals in the radial direction, determining values of characteristics of the crystals of the specimen plates by measurements, and by using evaluation values obtained by multiplying amounts of the crystals (relative amounts of the crystals) at sites where the specimen plates have been sampled by the values of the crystal characteristics.
METHOD FOR MANUFACTURING SILICON CARBIDE SINGLE CRYSTAL
A method for manufacturing a silicon carbide single crystal includes: packing a silicon carbide source material into a crucible, the silicon carbide source material having a flowability index of not less than 70 and not more than 100; and sublimating the silicon carbide source material by heating the silicon carbide source material.
MANUFACTURING METHOD OF MODIFIED ALUMINUM NITRIDE RAW MATERIAL, MODIFIED ALUMINUM NITRIDE RAW MATERIAL, MANUFACTURING METHOD OF ALUMINUM NITRIDE CRYSTALS, AND DOWNFALL DEFECT PREVENTION METHOD
The purpose of the present is to provide a modified AlN source for suppressing downfall defects. This manufacturing method of a modified aluminum nitride source involves a heat treatment step for heat treating an aluminum nitride source and generating an aluminum nitride sintered body.
Shielding member and apparatus for single crystal growth
A shielding member placed between a SiC source loading portion and a crystal installation portion in an apparatus for single crystal growth, including a crystal growth container including the loading portion which accommodates a SiC source in an inner bottom portion; a crystal installation portion facing the loading portion, and a heating unit configured to heat the crystal growth container. The device grows a single crystal of the SiC source on a crystal installed on the crystal installation portion by sublimating the SiC source from the loading portion. The shielding member includes a plurality of shielding plates, wherein each area of the plurality of shielding plates is 40% or less of a base area of the crystal growth container. When the SiC source loading portion is filled with a SiC source, a shielding ratio provided by a projection surface of the plurality of shielding plates is 0.5 or more.
ACTIVE CLEANING VACUUM SYSTEM AND METHOD
A vacuum system for silicon crystal growth includes a silicon crystal growth chamber, a first vacuum pipe, a second vacuum pipe, and an oxides container. The first vacuum pipe is coupled to the chamber and has within a first brush that is movable in a first direction for removing internal oxides. The second vacuum pipe is coupled to the first vacuum pipe for receiving the internal oxides via the first brush and has within a second brush that is movable in a second direction different from the first direction. The second brush transports the received internal oxides away from the first vacuum pipe. The oxides container is coupled to the second vacuum pipe for receiving the internal oxides via the second brush.
MANUFACTURING METHOD AND MANUFACTURING SYSTEM FOR SILICON SINGLE CRYSTAL
Spatial coordinates of multiple points on an inner surface of a vitreous silica crucible are measured prior to filling raw material in the vitreous silica crucible, and a three-dimensional shape of the inner surface of the vitreous silica crucible using a combination of polygons having vertex coordinates constituted by the respective measured points is specified (S11); a predictive value of an initial liquid surface level of the silicon melt in the vitreous silica crucible is preset (S12); a volume of the silicon melt satisfying the predictive value of the initial liquid surface level is obtained based on the three-dimensional shape of the inner surface of the vitreous silica crucible (S13); a weight of the silicon melt having the volume is obtained (S14); raw material having the weight is filled in the vitreous silica crucible (S15); a dipping control of the seed crystal is performed based on the predictive value of the initial liquid surface level (S17).
Process for Producing Silicon Single Crystal
In a process for producing a silicon single crystal in which carbon is incorporated in order to inhibit crystal defects, provided is a process which easily allows carbon to be mixed and dissolved into a silicon melt. The process for producing a silicon single crystal, which involves allowing a silicon single crystal to grow during its pulling-up from the silicon melt held in a crucible, uses as at least part of a silicon raw material, crushed materials of a polycrystalline silicon rod produced by Siemens process that are obtained by crushing an end of the rod in the vicinity contacting a carbon core wire holding member.
POLYCRYSTALLINE SILICON, FZ SINGLE CRYSTAL SILICON, AND METHOD FOR PRODUCING THE SAME
When FZ single crystal silicon is produced from polycrystalline silicon, which is synthesized by the Siemens method followed by being subjected to thermal treatment and includes crystal grains having a Miller index plane <111> or <220> as a principal plane and grown by the thermal treatment, and in which the X-ray diffraction intensity from either of the Miller index planes <111> and <220> after the thermal treatment is 1.5 times or less the X-ray diffraction intensity before the thermal treatment, as raw material, disappearance of crystal lines in the step of forming an FZ single crystal is markedly prevented.
Silicon carbide substrate and method of manufacturing the same
A silicon carbide substrate capable of stably forming a device of excellent performance, and a method of manufacturing the same are provided. A silicon carbide substrate is made of a single crystal of silicon carbide, and has a width of not less than 100 mm, a micropipe density of not more than 7 cm.sup.−2, a threading screw dislocation density of not more than 1×10.sup.4 cm.sup.−2, a threading edge dislocation density of not more than 1×10.sup.4 cm.sup.−2, a basal plane dislocation density of not more than 1×10.sup.4 cm.sup.−2, a stacking fault density of not more than 0.1 cm.sup.−1, a conductive impurity concentration of not less than 1×10.sup.18 cm.sup.−3, a residual impurity concentration of not more than 1×10.sup.16 cm.sup.−3, and a secondary phase inclusion density of not more than 1 cm.sup.−3.