Study on microscopic defects in Fe-doped InP single crystals

Effect of crystal growth conditions on the density of microscopic defects, observed on as-polished Fe-doped InP LEC single crystal wafers, has been investigated by an interference contrast microscope and a laser scattering tomography (LST) system. It was found that crystal rotation speeds affect the density of microscopic defects. In addition, the density depends on the duration for which the InP melt is held in molten state before crystal growth. On the other hand, it was found that the H ₂O concentration in B₂O₃ has no correlation with the generation of microscopic defects. The relationship between the microscopic defects and the stoichiometry of grown crystals was investigated by coulometric titration analysis for the indium concentration. The density of microscopic defects is reduced as the indium concentration decreased. From the present results, it is speculated that the origin of microscopic defects is indium or indium oxide