A vapor conduit for use in an apparatus for bulk vapor phase crystal growth, an apparatus for bulk vapor phase crystal growth, and a process for bulk vapor phase crystal growth are described. The vapor conduit is a flow conduit defining a passage means adapted for transport of vapor from a source volume to a growth volume, wherein a flow restrictor is provided in the passage means between the source volume and the growth volume and wherein the flow conduit further comprises a flow director structured to direct vapor flow downstream of the flow restrictor away from a longitudinal center line of the conduit and for example towards an edge of the conduit.

There is provided a semiconductor manufacturing device, including: a processing vessel; a partition wall that divides at least a part of a space in the processing vessel into a growth section and a cleaning section; a substrate holding member disposed in the growth section; a source gas supply system that supplies a source gas into the growth section; a cleaning gas supply system that supplies a cleaning gas into the cleaning section; and a heater that heats the growth section and the cleaning section.

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.

Roll forming is used for re-shaping an iridium crucible. The crucible is placed on a platen. The platen rotates the crucible while heat is applied by a plurality of torches. A plurality of rollers press on the rotating, heated crucible to re-shape. The roll forming allows for a greater number of repetitions of the re-shaping, increasing the number of uses per expensive re-fabrication of the crucible. The roll forming may provide more exact re-shaping.

To provide polycrystalline silicon suitable as a raw material for production of single-crystalline silicon. A D/L value is set within the range of less than 0.40 when multiple pairs of silicon cores are placed in a reaction furnace in production of a polycrystalline silicon rod having a diameter of 150 mm or more by deposition according to a chemical vapor deposition process and it is assumed that the average value of the final diameter of the polycrystalline silicon rod is defined as D (mm) and the mutual interval between the multiple pairs of silicon cores is defined as L (mm).

The invention provides a growth method for preparing high-yield crystals, belongs to the technical field of single crystal growth. Auxiliary crucibles are arranged on a crucible according to different crystal types and according to the crystal orientation of crystal growth in the main crucible, the relationship between the crystal growth direction and twin crystal orientation. By controlling the angle between the auxiliary crucibles and the main crucible, the relative position between the auxiliary crucibles each other, the auxiliary crucibles realize correction on the crystal orientation of twins generated in the main crucible crystal growth process. The growth method for preparing the high-yield crystals provided by the invention has the following advantages: the crystal orientation change caused by twins is corrected through auxiliary crucibles additionally arranged on the main crucible, and the overall yield is improved for the growth process of the dislocation crystal with large probability; the crucible position can be customized according to the influence of twins on the crystal growth direction, suitable for various crystal preparation processes, improving the yield obviously, reducing the crystal processing difficulty, and improving the material utilization rate.

Dust that is accumulated in an exhaust passage provided in a chamber, the exhaust passage for discharging gas in the chamber of a semiconductor crystal manufacturing device, is removed by being sucked from the outside of the chamber. Moreover, an opening and closing valve for cleaning that is detachably attached to an opening of the exhaust passage, the opening facing the chamber, is opened and closed intermittently in a suction state. Furthermore, the opening and closing valve for cleaning is driven by a valve driving unit. The dust accumulated in the exhaust passage is removed efficiently, whereby the time required to clean the exhaust passage is shortened and fluctuations of the pressure inside the chamber when a semiconductor crystal is manufactured are suppressed.

Dust that is accumulated in an exhaust passage provided in a chamber, the exhaust passage for discharging gas in the chamber of a semiconductor crystal manufacturing device, is removed by being sucked from the outside of the chamber. Moreover, an opening and closing valve for cleaning that is detachably attached to an opening of the exhaust passage, the opening facing the chamber, is opened and closed intermittently in a suction state. Furthermore, the opening and closing valve for cleaning is driven by a valve driving unit. The dust accumulated in the exhaust passage is removed efficiently, whereby the time required to clean the exhaust passage is shortened and fluctuations of the pressure inside the chamber when a semiconductor crystal is manufactured are suppressed.

Methods for purifying reaction precursors used in the synthesis of inorganic compounds and methods for synthesizing inorganic compounds from the purified precursors are provided. Also provided are methods for purifying the inorganic compounds and methods for crystallizing the inorganic compounds from a melt. γ and X-ray detectors incorporating the crystals of the inorganic compounds are also provided.

A cleaning method includes a first removal step of causing an inert gas to which a pulsation is applied to flow into an exhaust pipe after a silicon single crystal doped with an n-type dopant is produced, to peel and remove a deposit; and a second removal step of causing an atmospheric air to which no pulsation is applied to flow into the exhaust pipe through a chamber to burn a part of the deposit with the atmospheric air, the part being not removable in the first removal step, and peel and remove a burned substance of the deposit.