Komatsu Electronic Metals Co., Ltd.

Sumco Techxiv Corporation

Sumco Techxiv Kabushiki Kaisha

Tetsuhiro Iida

Junsuke Tomioka

Yutaka Shiraishi

Toshimichi Kubota

Toshiaki Saishoji

Toshiro Kotooka

Toshiaki Saishouji

Kouzou Nakamura

Ryota Suewaka

Shin Matsukuma

An upper side heateris configured so that a current passage width becomes larger at a heater lower part than at a heater upper part. Thus, the upper side heaterhas a current-carrying cross-sectional area which becomes larger at the heater lower part than at the heater upper part, a resistance value becomes accordingly smaller at the heater lower part than at the heater upper part, and a heat generation amount becomes relatively smaller at the heater lower part than at the heater upper part. Meanwhile, a lower side heateris configured so that the current passage width becomes larger at the heater upper part than at the heater lower part. Thus, the current-carrying cross-sectional area of the lower side heaterbecomes larger at the heater upper part than at the heater lower part, a resistance value becomes accordingly smaller at the heater upper part than at the heater lower part, and a heat generation amount becomes relatively smaller at the heater upper part than at the heater lower part.

Single crystal semiconductor manufacturing apparatus and manufacturing method

A Czochralski single crystal manufacturing apparatus uses multiple heaters to improve the controllability of crystal diameter. The power supplied to the multiple heaters is controlled so as to bring the pulling up speed close to a predetermined speed set value, and so as to bring the heater temperatures close to predetermined target temperature values. The ratio of electrical power between the heaters is controlled to agree with a predetermined power ratio set value which varies according to the crystal pulling up length, and the heater temperatures change along with this change, which causes disturbance to the diameter control. To compensate for this, heater temperature changes along with the power ratio set value change are taken into account in advance in the temperature set values. Accordingly, along with change of the power ratio set value, the temperature set values change to values appropriate for the current power ratio set value.

Single crystal manufacturing apparatus and method

A method for eliminating slip dislocations in producing single crystal silicon, a seed crystal capable of eliminating the slip dislocations, a single crystal silicon ingot from which the slip dislocations have been eliminated and a single crystal silicon wafer, are disclosed. Single crystal silicon is produced by dipping a seed crystal in a melt and pulling the seed crystal up along the axis of the seed crystal, using a single crystal () in which the &#x3c;110&#x3e; crystal orientation () is inclined at a predetermined angle &#x3b8; with respect to the axial direction () so that the edge direction () of the {111} crystal plane is inclined with respect to the axial direction (). When single crystal silicon is grown while pulling up a seed crystal by the CZ method, a single crystal silicon ingot of a large diameter and a heavy weight can be pulled up by eliminating slip dislocations from the thick crystal.

Single crystal silicon producing method, single crystal silicon wafer producing method, seed crystal for producing single crystal silicon, single crystal silicon ingot, and single crystal silicon wafer

A method for fabricating a single-crystal semiconductor by means of CZ method is disclosed. The method separates the single-crystal semiconductor from the melt by increasing the lift rate when the growth of a crystal body is finished. By controlling the lift rate, the single-crystal semiconductor is then gradually cooled within a range of an arbitrary crystal temperature, thereby forming a concave separated surface. The single-crystal semiconductor is cooled at a rate of lower than 35.degree. C./min when the temperature of the separated surface is within a range between the melting point and 1000.degree. C., or by keeping the temperature of the separated surface within a range between 1250.degree. C. and 1000.degree. C. for more than 30 minutes. Therefore, no dislocation is introduced in the crystal body, and productivity is improved.

Method for fabricating a single-crystal semiconductor

In the manufacture of a single crystal using a semiconductor single-crystal pulling apparatus equipped with a radiation screen, the time of passage of the single crystal through the high-temperature region of 1050.degree. C. and above is made to be long and the time of passage of the single crystal through the temperature region of about 900.degree. C.-500.degree. C. is made to be short. The semiconductor single-crystal pulling apparatus is so constructed that a radiation screen comprises an upper screen of 3-layer construction consisting of a heat-insulating member made of graphite or ceramics fiber clad with outer members made of graphite and a lower screen 3 of single-layer construction made of graphite, quartz or fine ceramics. Radiant heat from the molten liquid heats the lower part of single crystal as it passes through lower screen, thereby prolonging its period of passage through the high-temperature region. The radiant heat cannot reach single crystal when it is surrounded by upper screen, so it is cooled comparatively abruptly and can pass through the temperature region of about 900-500.degree. C. in a short time.

Growing community of inventors

Hiratsuka, Japan

Tetsuhiro Iida