PERPENDICULAR GIANT MAGNETORESISTANCE USING MICROLITHOGRAPHY AND SUBSTRATE PATTERNING TECHNIQUES

We present experimental results on the giant magnetoresistance effect in magnetic multilayers measured with the current perpendicular to the multilayer plane. Two different experimental techniques are used, whi ch both allow the study of the perpendicular magnetoresistance from 4 to 300 K. The first technique is based on the fabrication of pillar-li ke microstructures of Fe/Cr and Co/Cu multilayers using microlithograp hy and reactive ion etching. In the second technique we use holographi c laser interference nanofabrication and wet anisotropic etching to pa ttern V-shaped grooves of 0.2 mu m width into semi-insulating InP subs trates. Subsequently, a Co/Cu multilayer is evaporated al an angle wit h the substrate normal, naturally resulting in a perpendicular magneto resistance configuration. Both experimental techniques demonstrate tha t the perpendicular magnetoresistance is a factor 2 to 4 larger than t he conventional current-in-plane magnetoresistance.