Study On The Growth Of InGaAs Quantum Dots By Intermittent Source Disruption

Optoelectronics devices manufactured by quantum dots materials exhibitadvantageous performance, which derives from their discrete carrier energy levels.Direct energy gap materials supply high electron transition probability, compoundsemiconductor material InGaAs represents for a typical one. InGaAs material couldserve as active layer in laser diode and detector, its high carrier mobility draws a greatnumber of attentions. It is widely understood that their active layers ascertained mostdevices’ performances, therefore, how to obtain high-quality epitaxial InGaAsquantum dots surface on GaAs substrate should be a primary issue in the relevantstudies.The thesis mainly focused on two aspects: growth process of In0.5Ga0.5Asquantum dots and ripening time of single-layer In0.15Ga0.85As islands.First, In0.5Ga0.5As quantum dots are grown on GaAs(001) by molecular beamepitaxy in three various growth processes, which are Gallium template method,multi-periods method and chain-like quantum dots. Scanning turning microscopyimages illustrate the surface morphology. The growth principles of these three growthprocesses are illustrated and analyzed in detail.Second, the prediction of ripening time of single-layer In0.15Ga0.85As islands isstudied. Based on thermodynamic theory, a half-terrace diffusion theoretical modelwas proposed to estimate the annealing time for obtaining flat morphology.In conclusion, the size of In0.5Ga0.5As quantum dots increase as the substratetemperature rises. The distribution of In0.5Ga0.5As quantum dots differ from each otherbetween the three growth processes, and the annealing time calculated by theproposed ripening theory is in agreement with the experimental results.