TEM study of dislocations structure in In(0.82)Ga(0.18)As/InP heterostructure with InGaAs as buffer layer

In order to improve the quality of detector, In_x Ga_(1-x)As(x=0.82) buffer layer has been introduced in In_(0.82)Ga_(0.18)As/In P heterostructure. Dislocation behavior of the multilayer is analyzed through plane and cross section [110] by transmission electron microscopy(TEM) and high resolution transmission electron microscopy(HRTEM). The dislocations are effectively suppressed in In_x Ga_(1-x)As(x=0.82) buffer layer, and the density of dislocations in epilayer is reduced obviously. No lattice mismatch between buffer layer and epilayer results in no misfit dislocation(MD). The threading dislocations(TDs) are directly related to the multiplication of the MDs in buffer layer.

Structure optimization of high indium content InGaAs/InP heterostructure for the growth of In_(0.82)Ga_(0.18)As buffer layer

Microstructure and misfit dislocation behavior in In_xGa_(1-x)As/InP heteroepitaxial materials grown by low pressure metal organic chemical vapor deposition(LP-MOCVD) were analyzed by high resolution transmission electron microscopy(HRTEM), scanning electron microscopy(SEM), atomic force microscopy(AFM), Raman spectroscopy and Hall effect measurements. To optimize the structure of In_(0.82)Ga_(0.18)As/InP heterostructure, the In_xGa_(1-x)As buffer layer was grown. The residual strain of the In_(0.82)Ga_(0.18)As epitaxial layer was calculated. Further, the periodic growth pattern of the misfit dislocation at the interface was discovered and verified. Then the effects of misfit dislocation on the surface morphology and microstructure of the material were studied. It is found that the misfit dislocation of high indium(In) content In_(0.82)Ga_(0.18)As epitaxial layer has significant influence on the carrier concentration.