Large size semiconductor crystal with low dislocation density

摘要

A large semiconductor crystal has a diameter of at least 6 inches and a low dislocation density of not more than 1x10<4 >cm<-2>. The crystal is preferably a single crystal of GaAs, or one of CdTe, InAs, GaSb, Si or Ge, and may have a positive boron concentration of not more than 1x10<16 >cm<-3 >and a carbon concentration of 0.5x10<15 >cm<-3 >to 1.5x10<15 >cm<-3 >with a very uniform concentration throughout the crystal. Such a crystal can form a very thin wafer with a low dislocation density. A special method and apparatus for producing such a crystal is also disclosed.