公开(公告)号：US3621213A

公开(公告)日：1971-11-16

申请号：US3621213D

申请日：1969-11-26

Applicant: IBM

Inventor： JEN DIAN P ,  SLOCUM RICHARD A ,  VALENTINO CARL R

IPC: C30B15/22 ,  G06F15/46 ,  G06F9/06

CPC classification number: C30B15/22 ,  Y10T117/1008 ,  Y10T117/1068 ,  Y10T117/1072

Abstract: A Czochralski crystal puller is automatically controlled by a specially programmed digital computer to produce constant diameter, high-quality semiconductor crystals. Provision is made in the programming of the computer for the solution of partly theoretical and partly empirical mathematical models for simultaneously controlling heater temperature, crystal lift rate, crucible lift rate, crystal rotation rate and crucible rotation rate. Computer solutions of the equations are made in real time and the computer is an online integral component of the overall crystal growth system. The mathematical models concerned with heater temperature control and crystal lift control include data extrapolation for the anticipatory control of crystal diameter to compensate for the low dynamic response of the Czochralski crystal puller to changes in the heater control signals.