| 摘要 |
PURPOSE:To allow liquid phase growth of a compound semiconductor crystal with a good reproducibility, which is of low carrier concentration and semi- insulating, by adding two kinds of impurities that create a shallow energy level and a deep energy level to a common molten liquid for crystal growth. CONSTITUTION:A donor impurity such as Cr which creates a level at the depth of 450meV below the conduction band CB in the forbidden band gap BG and an acceptor impurity such as Cd which creates a shallow energy level at the depth of 40-50meV higher above the valance band VB in the forbidden band gap BG are used as impurities to be added. A certain quantity of molten liquid 9 for crystal growth is prepared by adding a quantity of Cr giving the concentra tion of about 1X10<-6> and a quantity of Cd giving the concentration of about 1X10<-4> both in the state of molten liquid to a prescribed weight of InP crystal followed by mixing. The molten liquid 9 thus prepared is placed on a InP sub strate 8 to accomplish crystal growth. In this way, a InP single crystal of low carrier concentration -4X10<14>cm<-3>- is obtained with a good reproducibility even in a growing system in which background impurities are mingled at a high concentration. |
