Patent · US Expired

Oxidation structure/method to fabricate a high-performance magnetic tunneling junction MRAM

US6974708B2 · kind B2 · utility

35Cited by
3References
13Claims
0Family size

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Key dates

Filing dateApr 8, 2004
Grant dateDec 13, 2005
Priority date
Expiry dateApr 8, 2024

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH10N50/01

Abstract

An MTJ (magnetic tunneling junction) MRAM (magnetic random access memory) has a tunneling barrier layer of substantially uniform and homogeneous Al2O3 stoichiometry. The barrier layer is formed by depositing Al on a CoFe layer or a CoFe—NiFe bilayer having an oxygen surfactant layer formed thereon, then oxidizing the Al by radical oxidation. The underlying surfactant layer contributes oxygen to the bottom surface of the Al, forming an initial amorphous Al2O3 layer. This layer produces small, uniform grains in the remaining Al layer, which promotes a uniform oxidation of the Al between its upper and lower surfaces by the subsequent radical oxidation. A final annealing process to set a pinned layer magnetization enhances the homogeneous oxidation of the layer.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.