Patent ID: 8936679
Filing Date: 2015-01-20
Classification: C30B,Y10T

Abstract:
1. A single crystal pulling-up apparatus of pulling-up silicon single crystals by a Czochralski method by bringing seed crystals into contact with a molten silicon liquid in a crucible and by growing a neck portion where an enlarged diameter portion and a reduced diameter portion are formed alternately, the apparatus comprising: a neck diameter measuring portion which measures a diameter of a grown neck portion; a first compensation portion which outputs a first compensated pulling-up speed for the seed crystals based on a difference between a measured value of the diameter of the neck portion obtained from the neck diameter measuring portion and a target value of the neck portion diameter previously stored in a storage portion; a second compensation portion which outputs a second pulling-up speed while limiting an upper limit of the first pulling-up speed to a first limit value; and a crucible rotation number compensation portion which lowers a number of a rotation of the crucible at least in a period where the upper limit of the first pulling-up speed is limited to the first limit value.