Scanning IR microscopy and transmission electron microscopy studies of inhomogeneities in LEC S-doped InP

Inhomogeneities in S-doped InP wafers from LEC-grown ingots were characterized by both scanning IR microscopy (SIRM) and transmission electron microscopy (TEM). The main inhomogeneities revealed were dislocations, both decorated with particles and non-decorated, interior and surface particles, and dopant striations. It was found that higher S doping gave a significantly lower dislocation density and more pronounced dislocation decoration. Post-grown annealing at 1000 °C resulted in a higher dislocation density and the formation of small interior precipitate particles of high density. The SIRM and TEM observations correlated well with each other.