PRECIPITATION IN FE-DOPED SEMI-INSULATING INP EPITAXIAL LAYER GROWN BY METALORGANIC CHEMICAL VAPOR-DEPOSITION (MOCVD)

The authors report the observation of small coherent precipitates in Fe-doped semi-insulating InP epitaxial layer grown by MOCVD on S-doped (001) InP substrate. Within the iron concentration range of 3 multiplied by 10**1**7 to 2 multiplied by 10**1**9 cm** minus **3, the density of precipitate increases with increasing iron concentration, while the size of precipitates (100-250A) remains more or less constant. These are identified as FeP. Due to the differences in lattice structures, precipitation of FeP instead of FeP//2 observed in bulk crystal can be rationalized in terms of the minimization of the misfit strain energy. Occasionally, slip-type dislocation structures were observed associated with the precipitates.