| 摘要 |
PROBLEM TO BE SOLVED: To solve the problem of causing breakage of the holder due to its insufficient strength at the time of pulling up a single crystal having about 300kg large gravity by using a seed crystal holder made of conventional graphite, or the problem of causing breakage of the holder due to comparatively small tensile strength among fiber layers of the holder material and an applied force greater than the withstand load to among fiber layers depending on the holder shape at the time of pulling up a single crystal by using a seed crystal holder made of carbon fiber cloth reinforced graphite in order to solve the former problems. SOLUTION: This holder 15 made of carbon fiber cloth reinforced graphite consists of an upper section 151 having a large-diameter cavity 151a, a lower section 153 having a small-diameter cavity 153a and an intermediate section 152 for connecting the upper section 151 and the lower section 153 to each other. In the holder 15, the angle (θ) between the wall inner surface 152b of the intermediate section 152 and the horizontal plane, the total vertical-sectional area (S) of the intermediate section 152 and the lower section 153, the tensile strength (σ) among fiber layers and the load (W) of a single crystal to be pulled up are set respectively so as to meet the relational expressionπσS/(sinθ.cosθ)>W.
|
