Twisting vibration detector for silicon@ monocrystal

摘要

The twisting vibration detector comprises a camera unit (1) placed at the outside of a silicon monocrystal growing chamber (2) so as to detect a rotation of a monocrystal (6) in the chamber, a memory unit (22) for processing and memorizing signals from the camera unit, and an arithmetic processing unit (21) for comparing signals from the camera unit and signals from the memory unit so as to decide a generation of an abnormal vibration of the silicon monocrystal. The twisting vibration detection method comprises detecting a seam portion (61) of a rotating silicon monocrystal by the camera unit, a step for memorizing time intervals of signals generated by detecting the seam portion, finding a mean value of the memorised time intervals, comparing time intervals of new signals from the camera unit and the calculated mean value, and deciding a generation of the abnormal vibration of the monocrystal when the deviation exceeding a specific value. The manufacture method feeds a signal to a silicon rotation drive unit when generation of an abnormal twisting vibration is decided so as to change the rotating speed of the silicon rotation drive unit.