DIFFUSION OF BOTH GA AND BI INTO INSB SEEDS DURING GROWTH OF INGASBBI

In1-xGaxSb1-yBiy (0 < x less-than-or-equal-to 0.21, 0 < y less-than-or -equal-to 0.005) quaternary bulk single crystals were grown on InSb se ed crystals using a rotary Bridgman method. In order to investigate th e quality of these crystals, various kinds of measurements were carrie d out, such as optical microscope, x-ray topograph, four-crystal x-ray diffractometry, electron-probe microanalysis, energy-dispersive spect roscopy, and secondary-ion-mass spectroscopy. All grown crystals were 10 mm in diameter and more than 10 mm in length. This indicates that t he rotary Bridgman method was useful to grow quaternary bulk single cr ystals. Owing to segregation, the compositional ratio of Bi (y) increa sed and that of Ga (x) decreased as crystals grew. During growth of In GaSbBi, both Ga and Bi diffused into the InSb seed and there appeared domains of InBi. For comparison, InSb1-yBiy (0 < y less-than-or-equal- to 0.05) and In1-xGaxSb (0 < x less-than-or-equal-to 0.16) were grown on InSb. It turned out that Bi did not diffuse into InSb without Ga, b ut Ga diffused without Bi. The incorporation of Ga produced the excess In and as a result InBi domains were formed.