Stability of AlAs in AlxGa1minus;xAshyphen;AlAshyphen;GaAs quantum well heterostructures

摘要

Data are presented on the longhyphen;term (gsim;8 yr) degradation of AlxGa1minus;xAshyphen;AlAs hyphen;GaAs quantum well heterostructure material because of the instability of underlying (internal) AlAs layers. Material containing thicker (0.4 mgr;m) AlAs lsquo;lsquo;buriedrsquo;rsquo; layers (confining layers) is found to be much less stable than material containing thinner (lsim;200 Aring;) AlAs layers. Hydrolysis of the AlAs layers because of cleaved edges and pinholes in the cap layers leads to the deterioration.