Magnetic tunnel junction stack

Abstract

A magnetic tunnel junction (300) structure includes a layer (308) of iron having a thickness in the range of 1.0 to 5.0 Å disposed between a tunnel barrier (306) and a free magnetic element (310) resulting in high magnetoresistance (MR), low damping and an improved ratio Vc/Vbd of critical switching voltage to tunnel barrier breakdown voltage for improved spin torque yield and reliability while requiring only a low temperature anneal. This improved structure (300) also has a very low resistance-area product MgON diffusion barrier (312) between the free magnetic element (310) and an electrode (314) to prevent diffusion of the electrode into the free layer, which assists in keeping the damping, and therefore also the switching voltage, low. With the low annealing temperature, the breakdown voltage is high, resulting in a favorable ratio of Vc/Vbd and in a high proportion of devices switching before breakdown, therefore improving the yield and reliability of the devices.

Dependencies are inferred from the claim text.