Patent · US Expired

Method of forming a magnetic tunneling junction (MTJ) MRAM device and a tunneling magnetoresistive (TMR) read head

US6960480B1 · kind B1 · utility

36Cited by
8References
19Claims
0Family size

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Key dates

Filing dateMay 19, 2004
Grant dateNov 1, 2005
Priority date
Expiry dateMay 19, 2024

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH10N50/10
  • WIPO fieldElectrical machinery, apparatus, energy
  • WIPO sectorElectrical engineering

Abstract

An MTJ (magnetic tunneling junction) device particularly suitable for use as an MRAM (magnetic random access memory) or a tunneling magnetoresistive (TMR) read sensor, is formed on a seed layer which allows the tunneling barrier layer to be ultra-thin, smooth, and to have a high breakdown voltage. The seed layer is a layer of NiCr which is formed on a sputter-etched layer of Ta. The tunneling barrier layer for the MRAM is formed from a thin layer of Al which is radically oxidized (ROX), in-situ, to form the layer with characteristics described above. The tunneling barrier layer for the read sensor formed from a thin layer of Al or a HfAl bilayer which is naturally oxidized (NOX), in situ, to form the barrier layer. The resulting device has generally improved performance characteristics in terms of GMR ratio and junction resistance.

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