Structural and compositional analysis of strain relaxed InGaAs/InP multi quantum wells

The structural and compositional analysis of strain relaxed InGaAs/InP multi quantum wells (MQWs) have been carried out using high resolution X-ray diffraction (HRXRD), Raman spectroscopy (RS) and Rutherford backscattering spectrometry (RBS). The surface morphology has been investigated by atomic force microscopy (AFM). No satellite peaks have been observed in the symmetrical X-ray scans indicating strong strain relaxation, highly mixed InGaAs/InP interfaces and no multilayer characteristics. This limits the structural as well as compositional analysis. Dynamical scattering theory based simulation package has been used to simulate the respective spectra and compared. The RS study shows huge Raleigh scattering induced background resulting low intense phonon modes. In spite of the background we could observe the GaAs and InAs type phonon modes which have been used for the analysis. The RBS studies also indicate the mixed InGaAs/InP interfaces with preferential GaAs and InP precipitation/segregation and the results are discussed in detail comparing with other complementary techniques. Also, AFM analysis has been utilized to obtain the composition in comparison with related literature