Method of manufacturing a magnetoresistive random access memory device

A method of manufacturing an MRAM device, the method comprising:

• forming a first magnetic layer on a substrate;
• forming a first metal layer on the first magnetic layer by performing a DC sputtering process;
• forming a first tunnel barrier layer that includes a first metal oxide by oxidizing the first metal layer at a first temperature with a mixed gas that includes an inert gas and oxygen gas;
• forming a second metal layer on the first tunnel barrier layer by performing a DC sputtering process;
• forming a second tunnel barrier layer that includes a second metal oxide by oxidizing the second metal layer with the mixed gas at a second temperature, that is greater than the first temperature;
• and
• forming a second magnetic layer on the second tunnel barrier layer.

A method of manufacturing an MRAM device, the method comprising:

• forming a first magnetic layer on a substrate;
• forming a first tunnel barrier layer on the first magnetic layer such that the first tunnel barrier layer includes a first metal oxide, the first metal oxide being formed by oxidizing a first metal layer;
• forming a second tunnel barrier layer on the first tunnel barrier layer such that the second tunnel barrier layer includes a second metal oxide, the second metal oxide being formed by oxidizing a second metal layer that includes a same metal as that of the first metal layer, such that the second tunnel barrier layer has a metal content that is less than a metal content of the first tunnel barrier layer;
• and
• forming a second magnetic layer on the second tunnel barrier layer.