INTERDIFFUSION IN INGAAS GAAS AND INGAAS/GAASP QUANTUM-WELLS/

The shape of In0.22Ga0.78As single quantum wells (SQW) grown by metal- organic vapour phase epitaxy (MOVPE) is changed by rapid thermal annea ling (RTA). Samples with GaAs barriers were compared with strain-compe nsated ones with GaAs0.82P0.18 barriers using high-resolution X-ray di ffraction (HRXRD), Auger electron spectroscopy (AES) and photoluminesc ence spectroscopy (PL). After annealing, the PL wavelength is decrease d and the luminescence intensity increased. In bare strain-compensated layers, In diffusion is slightly reduced at 850 degrees C annealing t emperature. Encapsulation with SiO2 leads to an increase of the In dif fusion up to a factor of 10. In this case, the diffusion process is do minated by vacancies and strain compensation is no longer effective. ( C) 1997 Elsevier Science S.A.