WET-TIP DIE FOR EFG CRYSTAL GROWTH APPARATUS

摘要

2064748 9201090 PCTABS00010 A novel capillary die and crystal growing method are provided for growing a hollow cristalline body by EFG. Inner and outer annular moats (114, 116) surround the die tip. Passageways (180) are provided for supplying melt (29) to those moats from a crucible (24), so that melt (29) in said moats will wet and cover the inner and outer exterior surfaces of the die tip during growth of a hollow crystalline body. The novel die may be constructed so as to have a lower die tip and a shorter capillary than EFG dies heretofore used to successfully grow hollow bodies. The die design facilitates keeping the temperature of the die tip substantially uniform about its circumference, thereby improving uniformity of thickness of the wall of the crystalline body (112) grown from a film of melt (110) on the die tip. The moats reduce the likelihood of the growth process being interrupted or adversely affected by flooding of the die. In the event the growth meniscus breaks, liquid silicon is captured in the moats, thereby preventing or reducing the likelihood of flooding of the die.