Research On Microstructures And Properties Of InGaAs/InP Heterojunction Materials With A High In Conten

InxGa1-xAs is the typical representative of Ⅲ-Ⅴ Semiconductors. The cutoff wavelength changes with the change of In content, the corresponding spectrum response range from 0.87μm to 3.5μm. InP is the substrate of InxGa1-xAs heterostructure materials, with increasing In contents, the InxGa1-xAs epitaxial layer will grow with large lattice mismatch on InP substrate. The quality of the epitaxial layer is seriously affected. Therefore, it is a great significance to study and prepare the high In component InxGa1-xAs semiconductor materials with excelent properties.In this paper, InxGa1-xAs/InP heterostructures with different In content and high In component InxGa1-xAs hetero epitaxial material with different thickness of the epitaxial layer were grown on InP substrate by metalorganic chemical vapor deposition(MOCVD) technique; The In0.83Ga0.17 As heterostructure materials prepared with graded buffer layer and the superlattice structure by molecular beam epitaxy(MBE). Using scanning electron microscope(SEM) and transmission electron microscopy(TEM) and Air Force Manual(AFM) and XRD and Holzer instrument and Raman scattering spectra as research tools, by studying the microstructure of the surface morphologies and interior microstructure, to study the effects of lattice mismatch on the material surface quality and interface structure, to analyze the formation mechanism of the dislocation and dislocation types and explore the methods to reduce the misfit dislocation.As the experimental results suggest: With the change of the In content, the surface quality of InxGa1-xAs epitaxial layer changed obviously; The larger the content of In component, the larger the lattice mismatch between the InxGa1-xAs epitaxial layer and the InP substrate; The greater the degree of mismatch, the mismatch stress is larger at the interface and the dislocation density is larger; When the content of In component is the same, the change of the thickness of the epitaxial layer will also affect the dislocation density at the surface of the material. No matter what kind of situation, dislocations in the epitaxial layer mainly from in the interface mismatch stress resulting from the loss of misfit dislocations and the substrate itself carries a small amount of defects; Graded buffer layer and superlattice structure can inhibit misfit dislocations and reduced the number of dislocations in the epitaxial layer.