SEED HOLDING MEMBER AND METHOD FOR PRODUCING POLYCRYSTALLINE SILICON USING THE SEED HOLDING MEMBER

摘要

A depressed section to be bent and separated is formed in an optional place so as to cause stress concentration in the depressed section when a breaking load is applied, thereby making it possible to bend the depressed section with a smaller load than is conventional. Disclosed are a seed holding member which is capable of preventing cracks from spreading to an unintended place of the seed holding member to lighten time and effort of the isolation work of the seed holding member and polycrystalline silicon by making the cracks spread along the depressed section, and a method for producing polycrystalline silicon using the seed holding member. A groove (16) to be bent and separated is formed on the outer peripheral surface of a graphite-made seed holding member (6) which is disposed at the bottom of a furnace for producing the polycrystalline silicon by a Siemens method so as to hold the bottom end of a seed (4) serving as a seed rod. The seed holding member (6) comprises a cylindrical base section (6a) having a first fitting hole (10) into which an electrode section (5) is inserted, a cylindrical barrel section (6b) having a smaller diameter than that of the base section (6a), and a truncated conical tip (6c) which is continued into the barrel section (6b), and which has a second fitting hole (13) into which the bottom end of the seed (4) is inserted.