Structural and transport properties of Mn /spl delta/-doped GaAs layers

Delta(/spl delta/)-doping of magnetic ions in III-V semiconductors allows locally high concentration of magnetic moments, which can lead to higher ferromagnetic transition temperature as is expected in III-V-based random-alloy magnetic semiconductors. We have recently found that a Mn /spl delta/-doped GaAs layer only with 0.3 ML Mn concentration showed ferromagnetic ordering when selective p-type doping was introduced. Curie temperature T/sub C/ was found to be as high as 172 K, far above T/sub C/ of random-alloy magnetic semiconductors (e.g. 110 K for GaMnAs. We investigate MBE growth, structural and transport properties of Mn /spl delta/-doped GaAs and its heterostructures.