Verfahren zum Ziehen von Einkristallen.

摘要

In a method for pulling a single crystal, employing a double crucible assembly (6), the dopent concentration of the molten raw material in an inner crucible (11) prior to the pulling, is raised to a value higher than the dopant concentration C of the molten raw material in the inner crucible (11) at the steady state. Furthermore, at the initial stage of the pulling, the raw material having a dopant content ration of no greater than kC is introduced into the outer crucible (10) at a rate greater than the rate of decrease of the molten raw material within the inner crucible (11) during the pulling, to achieve a concentration ratio of dopant between the inner and outer crucibles (11, 10) at a target value. Subsequently, the raw material having kC as the dopant content ratio is introduced into the outer crucible (10), at a rate equal to the rate of decrease of the motlen raw material during the pulling.