PREPARATION OF SINGLE CRYSTAL SEMICONDUCTOR

摘要

PURPOSE:To prepare as single crystal semiconductor having optionally controlled concn. of impurity and uniform distribution of impurity by impressing a magnetic field having a direction and strength controlled to a specified value to a melted semiconductor in a crucible supported freely rotatably. CONSTITUTION:Silicon starting materials are charged to a crucible 4 and the materials are heated by a heater 5 to cause melting. Then, seed crystal 9 is dipped in the melted silicon 10 and a chain 8 is pulled up while rotating the crucible 4 and the seed crystal 9 in the direction reverse to each other to grow single crystal of silicon 11. An annular superconductive magnet 15 is arranged to the outside of a chamber 1 with its axis inclined by a specified angle to the direction of gravity. Liquid helium is supplied from a liquid He refrigerator to the superconductive magnet 15. The growth of the single crystal silicon is performed by impressing a magnetic field to the melted silicon 10 by passing electric current through the superconductive magnet 15 and passing almost direct current of <=3% ripple factor through the heater 5.