Angle-dependent magnetoresistance measurements on epitaxial GaAs layers grown on conductive substrates
The well known geometrical magnetoresistance effect was applied to metal-semiconductor-metal and GaAs Gunn device-type structures as angle-dependent magnetoresistance measurement and it has been proved to be an effective tool. Using samples rotated in magnetic field, the method makes possible the simultaneous determination of the electron mobility in an epitaxial layer grown on a conductive substrate and the resistance of the contacts, as has been demonstrated by a great number of experimental results. Questions which arose during the experiments have been studied by computer simulations for a wide range of sample parameters. Model calculations have shown the requirements on the samples, on the conditions of the measurement and the limitations to the correctness of the fitted and resultant data. In practice limitations are not very severe for different real metal-semiconductor-metal structures.