| 摘要 |
<p><PICT:0827676/III/1> Semi-conductor material, such as silicon or germanium, is zone refined in an elongated hollow walled crucible C, shown in cross-section in Fig. 2, of metal of high electrical and thermal conductivity, by melting a limited zone of the material B by means of high - frequency heating coils A, and causing the molten zone to traverse the length of the material while circulating liquid F through the hollow walls of the crucible to cool the crucible. The crucible may be made of copper, silver or gold. When silicon is treated it may be heated initially by a susceptor to a temperature at which eddy currents are induced therein. The crucible may be arranged with the material below the centre of the coil so that the reaction between the electromagnetic field of the coil and the field due to the currents induced in the metal of the crucible with the field induced in the molten zone of the material, lifts the material out of contact with the crucible.</p> |
