Magnetoresistance measurements of different geometries on epitaxial InP and GaInAs/InP layers

Summary form only given. Two aspects of magnetoresistance measurements and their use are demonstrated. First "classical" geometrical magnetoresistance measurements on InP are studied. Three different sample geometries are used and results are compared: van der Pauw clover leaf type samples, classical six contact Hall bars and Corbino disks were used. Mobility results and their dependence on magnetic field intensity for different sample geometries are compared. Mobility values obtained by magnetoresistance and by Hall measurements are also compared. For these studies, highly doped InP layers have been obtained by vapour phase epitaxy on semi-insulating InP substrates. A method is presented and applied to sandwich structures in order to measure the geometrical magnetoresistance on epitaxial layers grown on conducting substrates. The resistance of metal-epitaxial layer-substrate-metal structures is measured as a function of the angle between the current and magnetic field vectors.