| 摘要 |
<p>Reactive gas (207) is released through a crystal source material (15) or melt to react with impurities and carry the impurities away as gaseous products or as precipitates or in light or heavy form. The gaseous products are removed by vacuum and the heavy products fall to the bottom of the melt. Light products rise to the top of the melt. After purifying, dopants (17) are added to the melt. The melt moves away from the heater (13) and the crystal (29) is formed. Subsequent heating zones re-melt and refine the crystal, and a dopant is added in a final heating zone. The crystal is divided, and divided portions of the crystal are re-heated for heat treating and annealing.</p> |
