METHOD OF GROWTH OF GAAS SINGLE CRYSTAL HAVING SEMIINSULATING PROPERTY

摘要

PURPOSE:To make a compensation ratio of a doped donor impurity constant in the direction of crystal growth, by removing a part rich in impurity from a GaAs polycrystalline ingot having a specific composition containing oxygen, regrowing single crystal from the melt of polycrystal. CONSTITUTION:Horizontal Bridgeman method is used. (i) The boat 3 having the seed crystal 2 of GaAs and the Ga-As mixture 4 containing the oxygen 5 is arranged in one side of the reaction tube 1, and As powder is placed on the other side of the diffusion barrier 6. Then, the tube 1 is heated, the melt of the mixture 4 and the As vapor 8 are formed, and cooled successively from part that is brought into contact with the seed crystal 2, to grow a polycrystalline ingot having a ratio of Ga/As of 1.0000001-1.1276598 and an oxygen concentration of 6X1015-1X1018cm-3. (ii) Then, ends including a tail side are removed from the ingot, and (iii) the prepared polycrystalline ingot 41 is melted by the same procedure as that of the process i to regrow the single crystal of GaAs.