Design, fabrication and characterization of nonometer-scale variable-geometry MIM tunnel junctions

Abstract

There is growing interest in a phenomenon known as magnetoresistance in such applications as high-density hard disk drives and magnetic read-heads. The structure used in these applications is a tunnel junction containing ferromagnetic materials and an insulating barrier tunnel oxide. The turmel oxide is typically an Aluminum oxide (AI2O3) film. The growth process for anodic AI2O3 was developed and characterized. Nonmagnetic tunnel junction test structure were designed and fabricated to test the electrical characteristics of the tunnel oxide. Current-voltage plots obtained from devices of different oxide thickness and area were used to determine the tunneling mechanism and to investigate possible fringe effects.