Magnetic memory device with multiple sidewall spacers covering sidewall of mtj element and method for manufacturing the same

A method for forming a magnetic memory device, comprising:

• providing a substrate;
• forming at least a magnetic tunneling junction (MTJ) stack on said substrate and etching said MTJ stack in a high-density plasma chemical vapor deposition (HDPCVD) chamber to pattern said MTJ stack into MTJ elements, wherein each of said MTJ elements comprises a reference layer, a tunnel barrier layer, and a free layer, and wherein said reference layer comprises at least one sub-layer that protrudes beyond a sidewall of said tunnel barrier layer, and wherein said tunnel barrier layer protrudes beyond a sidewall of at least one sub-layer of said free layer;
• and
• forming an in-situ sidewall protection layer when etching said MTJ stack, comprising:
• forming at least a first sidewall spacer on said sidewall of said free layer;
• forming at least a second sidewall spacer on said first sidewall spacer and said sidewall of said tunnel barrier layer;
• and forming at least a third sidewall spacer on said second sidewall spacer and at least a sidewall of said at least one sub-layer of said reference layer, wherein said etching of the MTJ stack and formation of said in-situ sidewall protection layer are carried out in said HDPCVD chamber without breaking vacuum thereof.