| 摘要 |
PURPOSE:To enable production of high-quality wafers substantially without waste, by heating a polycrystal Si plate partially having single crystal layers to convert at least a part into single crystal and doping the part with an impurity. CONSTITUTION:A polycrystal Si rod 1 is directly or after being crushed, melted in a heated quartz furnace 3 and extruded from the valve 4 at the bottom of the furnace 3 through casting nozzle 5 to form a polycrystal Si plate 2'. The plate 2' is introduced into CVD chamber 6 to form the CVD layer 7 of polycrystal Si on the surface. At this time, the layer 7 is made different in oxygen concentration from wafer plate 2'' or doped with dopants to form a layer having a polarization tendency to facilitate single crystallization. The layer 7 is irradiated with, e.g., electron beams 8 in the heat-treatment unit 11 to form a seed 9 of single crystal. Then, the intensity of beams 8 is controlled, when needed, heat is applied from the outside to convert the layer 7 from single crystal into single crystal Si 12.
|
