MRAM memory gets new recipe
Categorie(s) : Life @ MINATEC, News, Research
Published : 1 June 2019
Researchers at Spintec have come up with a new way to improve MRAM memory retention, using tungsten instead of tantalum in the magnetic tunnel junction stacks. When the stacks are made, they must be annealed to crystallize the junctions. During annealing, the tantalum tends to diffuse toward the tunnel barrier, absorbing oxygen in the process. It also absorbs some of the iron in the magnetic electrode, modifying the electrode’s chemical composition. These phenomena alter MRAM magnetoresistance and retention (how long information can be stored).
This undesirable effect occurs at temperatures greater than 300 °C; annealing can take place at temperatures of 400 °C. Therefore, it is a good idea to replace the tantalum with tungsten, which migrates less and captures less iron during annealing.