Dislocation Filter Based on LT-GaAs Layers for Monolithic GaAs/Si Integration

Abstract

The use of low-temperature (LT) GaAs layers as dislocation filters in GaAs/Si heterostructures (HSs) was investigated in this study. The effects of intermediate LT-GaAs layers and of the post-growth and cyclic in situ annealing on the structural properties of GaAs/LT-GaAs/GaAs/Si(001) HSs were studied. It was found that the introduction of LT-GaAs layers, in combination with post-growth cyclic annealing, reduced the threading dislocation density down to 5 × 106 cm−2, the root-mean-square roughness of the GaAs surface down to 1.1 nm, and the concentration of non-radiative recombination centers in the near-surface GaAs/Si regions down to the homoepitaxial GaAs level. Possible reasons for the improvement in the quality of near-surface GaAs layers are discussed. On the one hand, the presence of elastic deformations in the GaAs/LT-GaAs system led to dislocation line bending. On the other hand, gallium vacancies, formed in the LT-GaAs layers, diffused into the overlying GaAs layers and led to an increase in the dislocation glide rate. It was demonstrated that the GaAs/Si HSs obtained with these techniques are suitable for growing high-quality light-emitting HSs with self-assembled quantum dots.

Dynamics of Vacancy Formation and Distribution in Semiconductor Heterostructures: Effect of Thermally Generated Intrinsic Electrons

“…The high-temperature post-growth annealing of heterostructures is useful for the engineering of semiconductor devices because it allows band-gap structure modification [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 ] and an oscillator strength [ 10 , 11 ], controls hyperfine interaction [ 12 ], adjusts the dephasing time of excitons [ 13 ], and reduces strain gradients [ 14 , 15 , 16 , 17 , 18 , 19 ]. For III-V semiconductor heterostructures, the changes occurring at the annealing are based on the intermixing that proceeds via the vacancy-mediated mechanism in which the atom jumps into a vacancy induced by high-temperature heating at a neighboring lattice site [ 2 , 3 , 20 , 21 ].…”

Reduction of GaAs Buffer Thickness and Its Impact on Epitaxially Integrated III–V Quantum Dot Lasers on a Si Substrate

“…Electron channeling contrast images of (a) 3000 nm GaAs buffer, (b) 1500 nm GaAs buffer, and (c) 700 nm GaAs buffer on Si. (d) Recent TDD results of different research groups. ,− …”

Rationally Engineered Vertically Aligned β‐Ga2−xWxO3 Nanocomposites for Self‐Biased Solar‐Blind Ultraviolet Photodetectors with Ultrafast Response

“…PL spectroscopy reveals the recombination dynamics of photogenerated carriers. [42][43][44][45] Depending on the trap-state density and thermodynamically favorable transitions, the PL peak position and spectrum intensity are modulated according to the optimized growth conditions. Such characterization plays an essential role while tailoring and optimizing the material synthesis for photonic and optoelectronic applications.…”