A method for controlling of the specific resistance of a single crystal.

摘要

PURPOSE:To enable the control of specific resistance within a prescribed allowable range over the whole length of a single crystal by controlling the pressure in a chamber or the flow rate of inert gas supplied to the chamber according to a specific controlling pattern. CONSTITUTION:With the progress of pulling-up of an Si single crystal 9, the liquid level of molten Si 10 in a crucible 4 is lowered and, accordingly, the specific resistance of the pulled-up single crystal 9 is lowered. The evaporation rate of Sb increases with progress of the pulling up of the single crystal 9 and the lowering of the specific resistance of the single crystal 9 can be suppressed by adopting a controlling pattern to decrease the pressure in a chamber 2 with the pulling up of the single crystal 9 by adjusting the opening degree of a needle valve 22 and a mass-flow controller 15. The specific resistance of the pulled-up single crystal 9 can arbitrarily be controlled by controlling the pressure in the chamber 2 according to a prescribed controlling pattern inputted to a computer 25 and the resistance can be adjusted within a prescribed allowable range over the whole length of the single crystal 9.