Title :
Quantitative model for the kinetics of compositional intermixing in GaAs-AlGaAs quantum-confined heterostructures
Author :
Helmy, Amr Saher ; Aitchison, J.Stewart ; Marsh, John H.
Author_Institution :
Dept. of Electron. & Electr. Eng., Glasgow Univ., UK
Abstract :
A quantitative atomic-scale model for the kinetics of intermixing in GaAs-AlGaAs quantum-confined heterostructures is presented. The model takes into account the statistical nature of the defect diffusion through heterostructures and calculates its effect on the Ga-Al interdiffusion across the associated interfaces. The model has been validated by successfully predicting the observed amounts of bandgap shift induced by the process of hydrogen plasma induced defect layer intermixing, as well as for the process of impurity-free vacancy disordering using SiO2 caps. Good agreement between calculated and measured bandgap shifts has been observed. Values of the group-III vacancy diffusion coefficient, where the agreement took place, are between 2 and 3×exp[-2.72/kBT] cm2·s-1
Keywords :
III-V semiconductors; aluminium compounds; chemical interdiffusion; diffusion; energy gap; gallium arsenide; semiconductor device models; semiconductor quantum wells; vacancies (crystal); Ga-Al; Ga-Al interdiffusion; GaAs-AlGaAs; GaAs-AlGaAs quantum-confined heterostructures; SiO2; SiO2 caps; associated interfaces; bandgap shift; compositional intermixing; defect diffusion; group-III vacancy diffusion coefficient; heterostructures; hydrogen plasma induced defect layer intermixing; impurity-free vacancy disordering; intermixing kinetics; measured bandgap shifts; quantitative atomic-scale model; quantitative model; statistical nature; Diffusion processes; Helium; Hydrogen; Kinetic theory; Photonic band gap; Plasma measurements; Plasma temperature; Predictive models; Process control; Quantum wells;
Journal_Title :
Selected Topics in Quantum Electronics, IEEE Journal of
DOI :
10.1109/2944.720476
