EXCHANGE-BIASED MAGNETIC TUNNEL JUNCTIONS PREPARED BY IN-SITU NATURAL OXIDATION

Magnetic tunnel junctions, showing spin-dependent tunneling, are considered for future implementation in high density magnetic memories. A low device resistance is a key criterium for the implementation. In this paper, we discuss the transport properties of low-resistance tunnel barriers realized by in-situ natural oxidation of thin Al layers (< 1.3 nm). The resistance and magnetoresistance of the tunnel junctions is evaluated for different Al thickness and different oxidation times, showing tunnel magnetoresistance values of 20% for 1 kΩ.μm2. The voltage bias and temperature dependence of the transport properties is addressed, as well as the influence of thermal post-treatment.