Abstract
Authors report the diffusion and quantum well intermixing (QWI) effects of neutral F and B impurities in p- and n-type AlGaAs in the title system. B diffuses significantly in p-doped AlGaAs but only slightly in n-type AlGaAs after furnace annealing. B retards intermixing in p-AlGaAs. This may be due to interstitial B, which may reduce the native group III interstitial concentration. The mechanism of B impurity-induced disordering (IID) in n-AlGaAs may be attributed to both the diffusion of point defects generated during ion implantation and the Fermi level effect from the deep acceptor B subAS sup-. Extremely fast F diffusion rates, which may be correlated to an interstitial diffusion mechanism, are observed. Results from F IID suggest the possibility of F ionization, which gives rise to a higher electron concentration during annealing and leads to higher degrees of intermixing in n-AlGaAs. The intermixing rate of impurity-free vacancy disordering (IFVD) using an SiO2 cap is higher in n-type and intrinsic AlGaAs than in p-type AlGaAs, which suggests that diffusion of the group III vacancy is inhibited in p-type material that has a higher group III interstitial concentration. Results imply that n-i-p structures should be more effective than conventional p-i-n structures for the IFVD process. 16 refs.