Phosphorus concentration limitation in czochralski silicon crystals

摘要

The maximum phosphorus concentration that can be incorporated into a silicon crystal using Czochralski crystal growth method was investigated. The value was found to be related to hot zone configuration and is about 1.11 x 10~(20) atoms/cm~3 for 100 m (111) crystals grown from a short tank grower with an 18 kg charge size. This doping concentration corresponds to a resistivity value of 0.00071 #OMEGA#centre dotcm. When the tang-end of a growing crystal reached this doping concentration, dislocations were generated at the center of the crystal about 50 m above the solid/melt interface. The dislocation spropagated down to the solid/melt interface and resulted in growing a dislocated crystal from that point on. Dislocation loop clusters were observed int eh centers of wafers with resistivity lower than 0.00092 #OMEGA#centre dotcm. These clusters most likely were the slip dislocation sources.