Origin of crystallographic tilt in InGaAs/GaAs(001) heterostructure

Abstract

X-ray rocking curve measurements showed a significant crystallographic tilt in relaxed InGaAs layer grown on (001) GaAs. Transmission electron microscopy revealed that the origin of tilt is 60° dislocations generated having Burgers vectors of a same vertical edge component. Calculations using anisotropic elasticity show that this configuration of 60° dislocation array is energetically favorable when the tilt of epilayer is present as to remove the long range stress field induced by the vertical edge components at the interface.

Evolution of epilayer tilt in thick In Ga1−As metamorphic buffer layers grown by hydride vapor phase epitaxy

“…[110] substrates exhibiting a tendency to tilt [10][11][12][13]. The finding that the tilt varied with position is consistent with the in previous reports on In x Ga 1 À x As MBLs grown by MBE [8][9][10].…”

Lattice-mismatched InGaAs layers grown by OMVPE on GaAs based compliant substrates

“…Figure 3 shows the (004) rocking curves for 600 nm In 0.18 Ga 0.82 As grown on conventional and TB compliant GaAs substrates. 19 Whereas normally no tilt should be observed for layers grown on (001)-oriented substrates 20 , other authors did find tilt for such substrates. The (004) peak separation oscillation amplitude for the investigated InGaAs lattice-mismatch thickness window is given in Fig.…”

“…A signifi-cant reduction in peak separation oscillation for the azimuthal angles is seen for the InGaAs layer on the TB compliant substrate compared to the conventional GaAs substrate. 19,21 Recently tilting of InGaAs layers grown on bulk layers was observed for conventional GaAs substrates, whereas a significant decrease of the tilt was found for GaAs/Al x O y /GaAs compliant susbtrates. 4.…”

Tilt investigation of In(Al,Ga)As metamorphic buffer layers on GaAs (001) substrate: A novel technique for tilt determination

“…Structural investigation of the In(Al,Ga)As/GaAs heteroepitaxial system has been extensively performed due to its significance in electronic and optical device application . However, structural changes in these heterostructures after nucleation and glide of dislocations is yet to be explored . In this work, employing atomic force microscopy (AFM) and high resolution x‐ray diffraction (HRXRD), epitaxial tilt in the epilayer with respect to GaAs (001) oriented substrate has been explored.…”

“…Kang et al. show that the elastic energy associated with the MD is reduced if the MD Burgers vectors are preferentially oriented. According to this model, lattice tilt over the large area of the wafer is the result of elastic energy minimization.…”