| 摘要 |
1311558 Programmed crystal-pulling INTERNATIONAL BUSINESS MACHINES CORP 9 Nov 1970 [26 Nov 1969] 53156/70 Heading B1S [Also in Division G3] An on-line computer-controlled system for growing a crystal from a melt includes means for adjusting the temperature of melt and pulling rate in dependence on idealised and compensating mathematical models. As shown, the Czochralski method for growing single structured crystals from a silicon melt is used in an apparatus comprising a quartz crucible 4, containing a silicon charge the temperature of which is raised by a heater 11, enclosed within a cylindrical chamber 25. A reed 1 is lifted and rotated by a hollow shaft 3, driven by motors 5, 6 to produce a crystal 10. The crucible is rotated and lifted by a hollow shaft 5 driven by motors 8, 9. The surface of the melt 2 is observed by an operative, through a viewing port 24, who initiates the automatic control of crystal growing by an on-line computer system 12. The computer system receives over connections 13, 14, 16, 17 information relating to the speeds of motors 6-9, an indication of temperature of the melt at the bottom of the crucible over a connection 18, from a radiation sensor 30 via the hollow shaft 5, and over a connection 15, the crystal diameter as determined by a radiation sensor 31. The computer system 12 is promrammed to control the motors 6-9 through lines 19-22 and the heater, through a line 23, in accordance mathematical models. The melt temperature control is based upon a first mathematical model describing the heat energy flow into and out of the apparatus and a second mathematical model which compensates the idealized model for the uncontrolled parameters which are present in a physically realisable system. |
