Thermal balancing via distributed inert-gas streams for high-meniscus ribbon crystal growth

Superior melt growth of ribbon crystals by thermal profile control that is continuously variable, inert, and capable of heat extraction has been achieved. In the device developed, multiple inert-gas jets are directed at various parts of the hot zone, each with individually controlled flow adjustment. In a furnace at 1200°C, the temperature at one edge of a 38-mm-wide ribbon growth zone can be varied at a rate of 6.8°C per liter per minute of argon flow. Asymmetrical temperature profiles in the zone can be flattened to within ±1°C or symmetrically tailored. Silicon ribbons having uniform widths of 38 and 50 mm and grown with a high melt meniscus have been produced by the capillary action shaping technique with inert-gas thermal balancing. Such crystals show minority carrier lifetime values of up to about 300 μs.