MICROSTRUCTURE OF AL GAAS INTERFACE STUDIED BY SLOW POSITRON BEAM/

The interface models were founded, and the expressions of the relation between Doppler broadening S-parameter and the implanted energy of po sitrons were got based on the diffusion equation of positrons. Interfa ces formed between Al overlayer and the (110) surface of GaAs were stu died with slow positron beam. We found the system of Al/GaAs interface s could be well described by the perfectly absorbing linear interface model. From the results fitted by this model, we obtained the relation between the S-parameter of the interface and the annealing temperatur es or the overlayer thickness. The microstructure of interfaces and it s dynamical characters were discussed.