Mitsubishi Materials Corporation

Mitsubishi Materials Silicon Corporation

Mitsubishi Kinzoku Kabushiki Kaisha

Other

Mitsubishi Metal Corporation

Yoshiaki Arai

Kensho Sahira

Michio Kida

Keisei Abe

Norihisa Machida

Naoki Ono

Hisashi Furuya

Yasunari Ikeda

A system for growing high-quality, low-carbon-concentration single crystals which have an excellent gas-flow guiding function near the melt, containing 1) an inverted conical, flow-guide cover placed above and coaxially with a double-walled crucible, with its lower end located immediately above the surface of the melt and in the space between the outer surface of the single crystal to be grown and the inner surface of the sidewall of the inner crucible; 2) a short passage comprising a hole passing through the sidewall of the inner crucible at a position higher than the level of the melt; and 3) a flow guide cylinder placed above and coaxially with the double-walled crucible, with its lower end located immediately above the surface of the melt and in the space between the outer surface of the sidewall of the inner crucible and the inner surface of the sidewall of the outer crucible, all arranged in a furnace.

Semiconductor single-crystal growth system

A method for recycling a heat exchanger includes spreading the outer periphery of a metal pipe of a heat exchanger in a predetermined direction, and placing the heat exchanger in the rotary space of a crushing roll which rotates around the axis thereof while slanting at a predetermined angle in order to separate the heat exchanger to the metal pipe and radiating metal fins. The crushing apparatus is provided with a crushing assembly which incorporates a processing space extending at a downward slant at a predetermined angle, an inlet, and a crushing roll applied to the heat exchanger which is rotated about the axis thereof in the processing space and moving down the same.

Heat exchanger recycling method and crushing apparatus used for the same

Method for growing a semiconductor single-crystal

There is provided a double crucible for growing a silicon single crystal in which the partition wall 17 in the shape of ring is concentric with the main crucible 6 in the shape of bottomed cylinder and the lower end of the partition wall 17 is fixed on the inner bottom of the main crucible, and thus the outer crucible 18 and the inner crucible 19 are formed inside the main crucible. The partition wall 17 is uniform in thickness and has introducing holes 20 in its lower part which link the outer crucible with the inner crucible. The partition wall is made so that the inner diameter of its lower part may be smaller than the inner diameter of its upper part. Supposing that A is the diameter of the partition wall at a level of molten silicon, h is a depth from the surface of the molten silicon to the introducing holes, V(out) is an amount of molten silicon stored in the outer crucible, and V(in) is an amount of molten stored in the inner crucible, the relation of D/A=1.5 to 3, 2h/A&gt;1, and V(out)/V(in)=0.4 to 0.9, is satisfied. The invention reduces the number of coarse COPs of 0.3 .mu.m or greater in diameter generated after Sc-1 cleaning on the surface of a silicon wafer made of a single crystal bar grown without making larger in size the furnace of a silicon single crystal continuously growing apparatus.

Double crucible for growing a silicon single crystal

An apparatus for growing a single crystal is disclosed which includes a double crucible assembly. The double crucible assembly has an outer crucible and an inner crucible disposed in the outer crucible. A support member is provided for supporting the inner crucible, and the support member is formed of an inorganic oxide non-reactive with silicon oxide. The upper end portion of the inner crucible may be formed of the same inorganic oxide. Alumina or mullite is suitable as the inorganic oxide. With the above construction, silicon single crystals obtained by the crystal growing apparatus will be free of contamination by carbon or heavy metals, and will exhibit excellent quality.

Apparatus for growing single crystals

In apparatuses for melting semiconductor material and growing single crystals of semiconductor material, the apparatus comprising:

Apparatus for process for growing crystals of semiconductor materials

A crystal growing apparatus includes a crucible, a feed pipe and a pulling mechanism. The crucible serves to melt a crystalline material. The feed pipe serves to cause the crystalline material to fall into the crucible to charge the crucible with the crystalline material. The pulling mechanism serves to pull a single-crystal from the molten material in the crucible. The feed pipe has a lower end positioned slightly above the surface of the molten material in the crucible and including a plurality of baffle plates mounted on an inner peripheral wall thereof in longitudinally spaced relation to one another. The baffle plates are arranged so that a pitch defined between adjacent two baffle plates decreases toward the lower end of the feed pipe.

Apparatus for growing crystals

An apparatus for melting a semiconductor material and growing a semiconductor crystal from the melted material includes a susceptor having a peripheral rim, a quartz crucible assembly for receiving the semiconductor material therein. The crucible assembly includes an outer crucible housed in and supported by the susceptor and an inner crucible adapted to be so placed within the outer crucible as to define a multi-wall structure. The apparatus also includes at least one fluid passage for permitting the melted material to flow between the inner and outer crucibles when the multi-wall structure is defined by the inner and outer crucibles, a holder for holding the inner crucible, a heater disposed so as to surround the susceptor for heating the material in the crucible assembly, and a drive mechanism operable to move at least one of the holder and the susceptor vertically between a coupled position where the holder is supported by the susceptor in such a manner that the inner crucible is so placed within the outer crucible as to define the multi-wall structure and a released position where the holder is disengaged from the susceptor in such a manner that the inner crucible is released from the outer crucible. There is also provided a process which may be conveniently carried out in the apparatus described above.

Apparatus and process for growing crystals of semiconductor materials

In a method for pulling a single crystal, employing a double crucible assembly, the dopant concentration of the molten raw material in an inner crucible prior to the pulling, is raised to a value higher than the dopant concentration C of the molten raw material in the inner crucible at the steady state. Furthermore, at the initial stage of the pulling, the raw material having a dopant content ratio of no greater than kC is introduced into the outer crucible at a rate greater than the rate of decrease of the molten raw material within the inner crucible during the pulling, to achieve a concentration ratio of dopant between the inner and outer crucibles at a target value. Subsequently, the raw material having kC as the dopant content ratio is introduced into the outer crucible, at a rate equal to the rate of decrease of the molten raw material during the pulling.

Growing community of inventors

Omiya, Japan

Yoshiaki Arai