Shin-etsu Handotai Co., Ltd.

Chihiro Tashiro

Michiaki Oda

Naoki Nagai

Atsushi Ozaki

Isamu Harada

Shiniti Sugai

In a pulling apparatus operated according to the multi-pulling method or CCZ method, granular silicon material is first fed to a feed pipe from a feeder so as to form stagnation of the granular silicon material in the feed pipe. The feeding of the granular silicon material from the feeder to the feed pipe is repeatedly commenced and stopped so as to maintain the stagnation of the granular silicon material. The feed rate of the granular silicon material from the feeder to the feed pipe is increased with time until the feed of the silicon material is completed. This prevents abrasion of a coating or lining provided on the inner surface of the feeder and also prevents damage of the feeder. In a pulling apparatus operated according to the Czochralski method, after causing granular silicon material to stagnate in the feed pipe, the crucible is lowered or the feed pipe is raised, while the stagnation of the granular silicon material is maintained, so as to form an unmolten layer of the granular silicon material on the molten or solidified surface of the silicon melt. The unmolten layer is then melted, and the granular silicon material is fed onto the unmolten layer through the feed pipe while the stagnation of the granular silicon material in the feed pipe is maintained. Accordingly, silicon material can be recharged without damaging the crucible, so that productivity and manufacturing yield of silicon monocrystals can be improved.

Method for feeding granular silicon material, feed pipe used in the

A feeding reservoir 11 for intermittently or continuously feeding granular raw material into a pulling apparatus 1, a chamber 13 connected to the feeding reservoir 11 through a gate valve 12, a granular raw material supply section 15 by which the granular raw material is supplied to the chamber 13 through a gate valve 14 and a pressure adjustment means 20 which adjusts the inner pressure of the chamber 13 is provided, and the granular raw material is fed to the feeding reservoir 11 while maintaining the inner pressure of the feeding reservoir 11 as the same as the inner pressure of the single crystal pulling apparatus 1. This feeding method and structure makes it possible to feed an additional amount of granular raw material even during the continuous charging process and or the recharging process without interrupting the process and also to pull a heavy single crystal rod with a large diameter without increasing the capacity of the feeding reservoir.

Method for feeding a granular raw material and feeding apparatus

An automatic metering/supplying apparatus is used for subdividing a granular silicon material. A cone member is placed on the upper opening portion of a drum, which contains the granular silicon material, so as to hold the drum. Subsequently, the drum is turned upside down by a rotary-type drum-inverting machine. Meanwhile, a quartz recharge tube into which the granular silicon material is to be discharged is placed on an electronic scale so as to measure the amount of the silicon material supplied to the quartz recharge tube. A valve control unit opens the valve to start the supply of the silicon material and closes the valve when the measured weight reaches a predetermined weight. Dust produced in the vicinity of the valve is sucked by a dust collection mechanism. The automatic metering/supplying apparatus can automate work for subdividing the granular silicon material contained in the drum. Further, collection of dust maintains the working environment clean.

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Annaka, Japan

Chihiro Tashiro